Journal articles on the topic 'Polymer/nanocrystals composite material'
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Havryliuk, Yevhenii, Volodymyr Dzhagan, Anatolii Karnaukhov, Oleksandr Selyshchev, Julia Hann, and Dietrich R. T. Zahn. "Raman Spectroscopy and Thermoelectric Characterization of Composite Thin Films of Cu2ZnSnS4 Nanocrystals Embedded in a Conductive Polymer PEDOT:PSS." Nanomaterials 13, no. 1 (December 22, 2022): 41. http://dx.doi.org/10.3390/nano13010041.
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Cu2ZnSnS4 (CZTS) is an intensively studied potential solar cell absorber and a promising thermoelectric (TE) material. In the form of colloidal nanocrystals (NCs), it is very convenient to form thin films on various substrates. Here, we investigate composites of CZTS NCs with PEDOT:PSS, a widely used photovoltaics polymer. We focus on the investigation of the structural stability of both NCs and polymers in composite thin films with different NC-to-polymer ratios. We studied both pristine films and those subjected to flash lamp annealing (FLA) or laser irradiation with various power densities. Raman spectroscopy was used as the main characterization technique because the vibrational modes of CZTS NCs and the polymer can be acquired in one spectrum and thus allow the properties of both parts of the composite to be monitored simultaneously. We found that CZTS NCs and PEDOT:PSS mutually influence each other in the composite. The thermoelectric properties of PEDOT:PSS/CZTS composite films were found to be higher compared to the films consisting of bare materials, and they can be further improved by adding DMSO. However, the presence of NCs in the polymer deteriorates its structural stability when subjected to FLA or laser treatment.
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Choi, YongJae, and John Simonsen. "Cellulose Nanocrystal-Filled Carboxymethyl Cellulose Nanocomposites." Journal of Nanoscience and Nanotechnology 6, no. 3 (March 1, 2006): 633–39. http://dx.doi.org/10.1166/jnn.2006.132.
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Polymer nanocomposites are one of the important application areas for nanotechnology. Naturally derived organic nanophase materials are of special interest in the case of polymer nanocomposites. Carboxymethyl cellulose is a polyelectrolyte derived from natural materials. It has been extensively studied as a hydrogel polymer. Methods to modify the mechanical properties of gels and films made from CMC are of interest in our lab and in the commercial marketplace. The effect of nano-sized fillers on the properties of CMC-based composites is of interest in the development of novel or improved applications for hydrogel polymers in general and CMC in particular. This project investigated cellulose nanocrystals (CNXLs) as a filler in CMC and compared the effects to microcrystalline cellulose (MCC). The composite material was composed of CMC, MCC or CNXL, with glycerin as a plasticizer. CNXL and MCC concentrations ranged from 5% to 30%. Glycerin concentrations were kept constant at 10%. CNXLs improved the strength and stiffness of the resulting composite compared to MCC. In addition, a simple heat treatment was found to render the nanocomposite water resistant.
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WEI, Haotong, and Bai YANG. "POLYMER-NANOCRYSTALS COMPOSITE MATERIALS AND PERFORMANCE OPTIMIZATION." Acta Polymerica Sinica 011, no. 9 (September 21, 2011): 939–49. http://dx.doi.org/10.3724/sp.j.1105.2011.11136.
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Dutta, Sayan Deb, Dinesh K. Patel, Yu-Ri Seo, Chan-Woo Park, Seung-Hwan Lee, Jin-Woo Kim, Jangho Kim, Hoon Seonwoo, and Ki-Taek Lim. "In Vitro Biocompatibility of Electrospun Poly(ε-Caprolactone)/Cellulose Nanocrystals-Nanofibers for Tissue Engineering." Journal of Nanomaterials 2019 (October 15, 2019): 1–11. http://dx.doi.org/10.1155/2019/2061545.
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Cellulose nanocrystals (CNCs) have emerged as promising materials for the fabrication of micro/nanoplatforms that can replace tissues more effectively. CNCs offer interesting properties that facilitate the enhancement of polymer properties. Cytotoxicity of rice husk-derived CNCs was evaluated through WST-1 assay in the presence of human mesenchymal stem cells. Electrospinning technique was used to fabricate nanofibers of poly-ε-caprolactone and its composites. Significant improvement in the mechanical property was observed in the composites relative to the pure polymer. This improvement was attributed to the better interfacial interactions between the polymer matrix and CNCs. Notably, better cell viability and differentiation were observed with the composite nanofibers than with the pure polymers. The osteogenic potential of the fabricated nanofibers was assessed by alizarin red S staining and real-time PCR. Enhanced mineralization occurred in the presence of the composite rather than pure polymer nanofibers. Furthermore, the higher levels of osteogenic markers observed with the media containing the composites clearly indicated their osteogenic potential. These results suggested that fabricated composites have the potential to be used as a biomaterial for tissue engineering applications.
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Su, Si, Shaoying Hu, and Qi Liu. "Application of Polypyrrole Cellulose Nanocrystalline Composite Conductive Material in Garment Design." Advances in Materials Science and Engineering 2022 (September 21, 2022): 1–11. http://dx.doi.org/10.1155/2022/4187826.
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The Chinese nation has a long cultural history and has deep attainments in food, clothing, art, and other cultural fields. With the development of science, technology, economy, and culture, new materials continue to appear, providing new ideas for clothing design. Polypyrrole is a common conductive polymer. The pure pyrrole monomer presents a colorless oily liquid at room temperature, slightly soluble in water and nontoxic. Nanocrystals, also called nanoscale crystals, use high-energy polymer spheres to pack calcium, magnesium ions, and bicarbonate in water to produce a water-insoluble crystal structure. Conductive composite materials mainly refer to composite conductive polymer materials, which are composed of polymers and various conductive substances through a certain composite method. This article aims to study the application of polypyrrole cellulose nanocrystalline composite conductive material in clothing design. Starting from the structural characteristics of the polypyrrole cellulose nanocrystalline composite conductive material, this article uses case analysis to study deeply the suitable polypyrrole cellulose nanocrystalline composite conductive material. This article can effectively use the innovative application method of its appearance style, so as to realize its application in clothing design. Starting from the functional properties of the polypyrrole cellulose nanocrystalline composite conductive material, the specific application of the polypyrrole cellulose nanocrystalline composite conductive material in different clothing designs is analyzed. Combining the postmodernist clothing style characteristics, aesthetic habits, and the characteristics of polypyrrole cellulose nanocrystalline composite conductive materials, this paper studies the innovative style design of polypyrrole cellulose nanocrystalline composite conductive materials. The experimental results in this paper show that when the reaction time is 2 min, the reaction rate at this time is zero, indicating that this time is in the initial stage of the reaction. After 4 minutes, as the reaction time increases, the reaction rate shows an increasing trend; when the reaction time is longer than 10 minutes, the reaction rate increases slowly and has a downward trend, which indicates the end of the reaction. The highest average reaction rate is about 7.5 mg/min.
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Barkane, Anda, Edgars Kampe, Oskars Platnieks, and Sergejs Gaidukovs. "Cellulose Nanocrystals vs. Cellulose Nanofibers: A Comparative Study of Reinforcing Effects in UV-Cured Vegetable Oil Nanocomposites." Nanomaterials 11, no. 7 (July 9, 2021): 1791. http://dx.doi.org/10.3390/nano11071791.
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There is an opportunity to use nanocellulose as an efficient renewable reinforcing filler for polymer composites. There have been many investigations to prove the reinforcement concept of different nanocellulose sources for thermoplastic and thermoset polymers. The present comparative study highlighted the beneficial effects of selecting cellulose nanofibers (CNFs) and nanocrystals (CNCs) on the exploitation properties of vegetable oil-based thermoset composite materials—thermal, thermomechanical, and structural characteristics. The proposed UV-light-curable resin consists of an acrylated epoxidized soybean oil polymer matrix and two different nanocellulose reinforcements. High loadings of up to 30 wt% of CNFs and CNCs in irradiation-cured vegetable oil-based thermoset composites were reported. Infrared spectroscopy analysis indicated developed hydrogen-bonding interactions between the nanocellulose and polymer matrix. CNCs yielded a homogeneous nanocrystal dispersion, while CNFs revealed a nanofiber agglomeration in the polymer matrix, as shown by scanning electron microscopy. Thermal degradation showed that nanocellulose reduced the maximum degradation temperature by 5 °C for the 30 wt% CNC and CNF nanocomposites. Above the glass transition temperature at 80 °C, the storage modulus values increased 6-fold and 2-fold for the 30 wt% CNC and CNF nanocomposites, respectively. In addition, the achieved reinforcement efficiency factor r value for CNCs was 8.7, which was significantly higher than that of CNFs of 2.2. The obtained nanocomposites with enhanced properties show great potential for applications such as UV-light-processed coatings, adhesives, and additive manufacturing inks.
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Wijaya, Christian J., Felycia E. Soetaredjo, Suryadi Ismadji, and Setiyo Gunawan. "Synthesis of Cellulose Nanocrystals/HKUST-1 Composites and Their Applications: Crystal Violet Removal and Doxorubicin Loading." Polymers 14, no. 22 (November 18, 2022): 4991. http://dx.doi.org/10.3390/polym14224991.
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This study developed a novel composite material containing cellulose nanocrystals (CNCs) and HKUST-1. Here, the addition of CNCs was used to enhance the characteristics of HKUST-1 in terms of surface area, adsorption ability, and functional groups. Here, the fabrication of CNCs@HKUST-1 composites was carried out by adding CNCs into the fabrication process of HKUST-1. The addition of CNCs provides additional functional groups on the surface of composite material which can be used to attach other organic compounds, such as in waste management and drug delivery systems. Here, CNCs@HKUST-1 composites were tested as a material for crystal violet (CV) removal and doxorubicin (DOX) loading. The removal capacity of CNCs@HKUST-1 composite towards CV molecules reached 1182.25 ± 27.74 mg/g, while the loading capacity for DOX drugs was around 1514.94 ± 11.67 mg/g. Both applications showed that CNCs@HKUST-1 composite had higher adsorption capacity and ability compared to its precursor materials, i.e., CNCs and HKUST-1.
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Yu, Hongquan, Hongwei Song, Guohui Pan, Libo Fan, Suwen Li, Xue Bai, Shaozhe Lu, and Haifeng Zhao. "Preparation and Luminescent Properties of Polymer Fibers Containing Y2O3:Eu Nanoparticles by Electrospinning." Journal of Nanoscience and Nanotechnology 8, no. 11 (November 1, 2008): 6017–22. http://dx.doi.org/10.1166/jnn.2008.480.
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In this paper, composite fibers of polyvinylpyrrolidone (PVP) and Y2O3:Eu3+ nanocrytals were prepared by electrospinning and characterized by electron microscope, Fourier transform infrared spectra (FT-IR) and X-ray diffraction (XRD). The composite fibers are in random orientation and with average diameter of ∼300 nm and length up to several ten micrometers. The luminescent properties were investigated and compared with the pure Y2O3:Eu3+ nanocrystals. Due to certain weak interactions between nanocrystals and PVP matrix, charge transfer band in the excitation spectra show slightly red shift for the fibers relative to in the case of pure Y2O3:Eu3+ nanocrystals. The PVP polymer may modified the surface defect states of nanocrystals, yielding decreased intensity ratio of 5D0–7F2 to 5D0–7F1 transition in the emission spectra. The fluorescence lifetimes of 5D0 level for Eu3+ in the composite fibers and Y2O3:Eu3+ nanocrystals were respectively determined to be 1.40 and 1.74 ms. The decreased fluorescence lifetime in the composite fibers was attributed to increased radiative transition rate, as result of the influence of refractive index of the surrounding PVP media instead of air.
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Rasheed, Masrat, Mohammad Jawaid, and Bisma Parveez. "Bamboo Fiber Based Cellulose Nanocrystals/Poly(Lactic Acid)/Poly(Butylene Succinate) Nanocomposites: Morphological, Mechanical and Thermal Properties." Polymers 13, no. 7 (March 29, 2021): 1076. http://dx.doi.org/10.3390/polym13071076.
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The purpose of this work was to investigate the effect of cellulose nanocrystals (CNC) from bamboo fiber on the properties of poly (lactic acid) (PLA)/poly (butylene succinate) (PBS) composites fabricated by melt mixing at 175 °C and then hot pressing at 180 °C. PBS and CNC (0.5, 0.75, 1, 1.5 wt.%) were added to improvise the properties of PLA. The morphological, physiochemical and crystallinity properties of nanocomposites were analysed by field emission scanning electron microscope (FESEM), Fourier-transform infrared spectroscopy (FTIR) and X-ray diffractometry (XRD), respectively. The thermal and tensile properties were analysed by thermogravimetic analysis (TGA), Differential scanning calorimetry (DSC) and Universal testing machine (UTM). PLA-PBS blend shows homogeneous morphology while the composite shows rod-like CNC particles, which are embedded in the polymer matrix. The uniform distribution of CNC particles in the nanocomposites improves their thermal stability, tensile strength and tensile modulus up to 1 wt.%; however, their elongation at break decreases. Thus, CNC addition in PLA-PBS matrix improves structural and thermal properties of the composite. The composite, thus developed, using CNC (a natural fiber) and PLA-PBS (biodegradable polymers) could be of immense importance as they could allow complete degradation in soil, making it a potential alternative material to existing packaging materials in the market that could be environment friendly.
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Thompson, Lachlan, Jalal Azadmanjiri, Mostafa Nikzad, Igor Sbarski, James Wang, and Aimin Yu. "Cellulose Nanocrystals: Production, Functionalization and Advanced Applications." REVIEWS ON ADVANCED MATERIALS SCIENCE 58, no. 1 (April 1, 2019): 1–16. http://dx.doi.org/10.1515/rams-2019-0001.
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Abstract Cellulose nanocrystals (CNC) are a class of nanoscale biopolymers produced from cellulose sources. CNC materials have gained growing interests which can be attributed to their excellent properties such as excellent biocompatibility, good mechanical properties and high aspect ratio whilst also being an inexpensive material that can be produced from green and renewable sources. Due to the abundant hydroxyl functional groups, the surface of CNC materials are ready to be tuned and functionalized via chemical reactions allowing for many different applications, such as being a reinforcing agent to be incorporated into a hydrophobic polymer matrix. In this review paper,we firstly introduce the general methods for producing CNC from different sources. Different strategies used for surface modification ofCNCare then discussed. Finally, the recent progress on the applications of CNC and CNC composite materials are described in detail.
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Zhu, Chunxia, Shuyu Pang, Zhaoxia Chen, Lehua Bi, Shuangfei Wang, Chen Liang, and Chengrong Qin. "Synthesis of Covalent Organic Frameworks (COFs)-Nanocellulose Composite and Its Thermal Degradation Studied by TGA/FTIR." Polymers 14, no. 15 (August 2, 2022): 3158. http://dx.doi.org/10.3390/polym14153158.
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At present, the synthesis methods of crystalline porous materials often involve powder products, which not only affects the practical application but also has complex synthesis operations and limited scale. Based on the mechanochemical method, we choose COF-TpPa-1, preparing TpPa-1-DANC composites. Covalent organic frameworks (COFs) are a kind of crystalline material formed by covalent bonds of light elements. COFs possess well pore structure and high thermal stability. However, the state of synthesized powders limits their application. Cellulose nanocrystals (CNCs) are promising renewable micron materials with abundant hydroxyl groups on their surface. It is possible to prepare high-strength materials such as film, water, and aerogel. Firstly, the nanocellulose was oxidized by the sodium periodate method to obtain aldehyde cellulose nanocrystals (DANC). TpPa-1-DANC not only had the crystal characteristic peak of COFs at 2θ ≈ 5° but also had a BET surface area of 247 m2/g. The chemical bonds between COFs and DANC formed by Schiff base reaction appeared in FTIR and XPS. The pyrolysis behavior of the composite was characterized by TG-IR, which showed that the composite had good thermal stability. With the advantages of nanocellulose as a material in every dimension, we believe that this method can be conducive to the large-scale synthesis of COFs composites, and has the possibility of multi-form synthesis of COFs.
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Ramrakhiani, Meera, Nitendra Kumar Gautam, Kamal Kushwaha, Sakshi Sahare, and Pranav Singh. "Electroluminescence in Chalcogenide Nanocrystals and Nanocomposites." Defect and Diffusion Forum 357 (July 2014): 127–69. http://dx.doi.org/10.4028/www.scientific.net/ddf.357.127.
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Several research groups have reported that nanocrystalline II-VI semiconductors show enhanced luminescence, increased oscillator strength and shorter response time. Nanocrystalline powder samples of CdS, CdSe, ZnS and ZnSe nanocrystals and their composites with PVA and PVK have been prepared by chemical route. SEM. TEM and AFM images indicate agglomeration of particles. XRD reveal the crystal structure and size in nanometer range and absorption spectra show increased band gap due to quantum confinement.The EL studies on nanocrystalline powder samples and nanocrystal/polymer composites have shown that the light emission starts at certain threshold voltage, different for different specimens and then increases with increasing voltage. It is found that smaller nanocrystals have lower threshold voltage and higher EL brightness. It is observed that nanocomposite give much higher electroluminescence starting at lower voltage and increasing very fast with the voltage as compared to nanocrystalline powder. The emission spectra are found to depend on the material, crystalline size and doping. Electroluminescence in undoped and doped chalcogenide nanocrystals and nanocomposites is reviewed in this paper. In nanosize regime, electroluminescence (EL) is governed by the size quantization effect. Contents of Paper
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Ferreira, Filipe, Ivanei Pinheiro, Sivoney de Souza, Lucia Mei, and Liliane Lona. "Polymer Composites Reinforced with Natural Fibers and Nanocellulose in the Automotive Industry: A Short Review." Journal of Composites Science 3, no. 2 (May 13, 2019): 51. http://dx.doi.org/10.3390/jcs3020051.
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Environmental concerns and cost reduction have encouraged the use of natural fillers as reinforcement in polymer composites. Currently, a wide variety of reinforcement, such as natural fibers and nanocellulose, are used for this purpose. Composite materials with natural fillers have not only met the environmental appeal, but also contribute to developing low-density materials with improved properties. The production of natural fillers is unlimited around the world, and many species are still to be discovered. Their processing is considered beneficial since the natural fillers do not cause corrosion or great wear of the equipment. For these reasons, polymer reinforced with natural fillers has been considered a good alternative for obtaining ecofriendly materials for several applications, including the automotive industry. This review explores the use of natural fillers (natural fibers, cellulose nanocrystals, and nanofibrillated cellulose) as reinforcement in polymer composites for the automotive industry.
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SCHNEIDER-POLLACK, SAMANTHA, MONA DOSHI, JEFF GELDMEIER, and ANDRE J. GESQUIERE. "P3HT CHAIN MORPHOLOGY IN COMPOSITE P3HT/PCBM NANOPARTICLES STUDIED BY SINGLE PARTICLE FLUORESCENCE EXCITATION POLARIZATION SPECTROSCOPY." Biophysical Reviews and Letters 08, no. 03n04 (December 2013): 243–53. http://dx.doi.org/10.1142/s1793048013500082.
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The use of conjugated polymers such as poly(3-hexylthiophene) (P3HT) in the active layers of plastic electronic devices could provide a more practical and accessible form of energy production and storage. The efficiency of these devices is intimately connected to the morphology of the polymer chains in the active layer materials, as polymer folding affects mesoscale material morphology. The latter in turn influences electronic structure and thus performance of the active layer. It is, however, highly challenging to determine molecular structure and folding properties in a bulk material. Here, it is shown that through the use of nanoparticles as a model system for the bulk material insight in molecular morphology can be gained through single particle fluorescence excitation spectroscopy. The study of P3HT chain morphologies was accomplished through the investigation of neat (0 wt% PCBM) P3HT nanoparticles and 25, 50 and 75 wt% PCBM blended P3HT nanoparticles. A striking discontinuous trend in P3HT chain morphology as a function of PCBM blending ratio was observed, where P3HT morphologies at 25 wt% and 75 wt% blending ratios appear to be more disordered than those observed for the 50 wt% blending ratio. These data suggest that at least from the morphological perspective, the 1:1 blending ratio appears to yield the better P3HT chain alignment. [Formula: see text]Special Issue Comment: This paper about solving single molecule conformations is related to the papers in this Special Issue on mathematical models for treatment of single molecule trajectories,1 nonblinking inorganic nanocrystals,2 and hybrid quantom dot–fullerence composite nanoparticles.3
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Xiong, Sha, Shihua Huang, Aiwei Tang, and Feng Teng. "Electroluminescence from Light-Emitting Diodes by Using Water-Dispersed ZnSe Nanocrystals and Polymer." Journal of Nanoscience and Nanotechnology 8, no. 3 (March 1, 2008): 1341–45. http://dx.doi.org/10.1166/jnn.2008.18193.
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Electroluminescence was obtained from an indium-tin-oxide/poly[2-methoxy-5-(2′-ethylhexyloxy)-1,4-phenylene vinylene] (MEH-PPV): ZnSe/2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP)/8-tris-hydroxyquinoline (Alq3)/LiF/Al structured device, in which ZnSe nanocrystals were synthesized in aqueous solution by using mercapto-acetate acid as stabilizer. The mechanical, electrical, and optical properties of the device were established. The photoluminescence and electroluminescence spectra changed with the mass ratio of ZnSe to MEH-PPV in the composite. Comparison between the absorption spectra and photoluminescence spectra of the ZnSe nanocrystals and the MEH-PPV thin film exhibited an effective energy transfer from ZnSe nanocrystals to MEH-PPV, which was one reason for the difference between the photoluminescence and electroluminescence spectra of the MEH-PPV: ZnSe composite film. The recombination mechanism of ZnSe nanocrystals under photo excitation and electric injection was investigated with the help of a single layer device structure of indium-tin-oxide/ZnSe/LiF/Al.
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Kan, Hong Min, Ning Zhang, Xiao Yang Wang, and Hong Sun. "Recent Advances in Hydrogen Storage Materials." Advanced Materials Research 512-515 (May 2012): 1438–41. http://dx.doi.org/10.4028/www.scientific.net/amr.512-515.1438.
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An overview of recent advances in hydrogen storage is presented in this review. The main focus is on metal hydrides, liquid-phase hydrogen storage material, alkaline earth metal NC/polymer composites and lithium borohydride ammoniate. Boron-nitrogen-based liquid-phase hydrogen storage material is a liquid under ambient conditions, air- and moisture-stable, recyclable and releases H2controllably and cleanly. It is not a solid material. It is easy storage and transport. The development of a liquid-phase hydrogen storage material has the potential to take advantage of the existing liquid-based distribution infrastructure. An air-stable composite material that consists of metallic Mg nanocrystals (NCs) in a gas-barrier polymer matrix that enables both the storage of a high density of hydrogen and rapid kinetics (loading in <30 min at 200°C). Moreover, nanostructuring of Mg provides rapid storage kinetics without using expensive heavy-metal catalysts. The Co-catalyzed lithium borohydride ammoniate, Li(NH3)4/3BH4 releases 17.8 wt% of hydrogen in the temperature range of 135 to 250 °C in a closed vessel. This is the maximum amount of dehydrogenation in all reports. These will reduce economy cost of the global transition from fossil fuels to hydrogen energy.
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Lahariya, Vikas. "Study of Electroluminescence in Cadmium Sulfide Polymer Nanocomposite Films." Journal of Nano Research 49 (September 2017): 181–89. http://dx.doi.org/10.4028/www.scientific.net/jnanor.49.181.
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Nanocrystalline cadmium sulfide/Polyvinyl alcohol composite films were prepared by chemical route using Cadmium acetate and hydrogen sulfide gas as cadmium and sulfur source respectively. Poly vinyl Alcohal (PVA) used as polymer matrix. The initially loading of cadmium precursor influences the size as well as photoluminescence and electroluminescence properties of the Composite film. The films were characterized by X Ray Diffraction (XRD), Atomic Force Microscopy (AFM) and UV-Visible Absorption spectra. The X-ray Diffraction result showed that CdS nanocrystals embedded in polymer matrix were in a zinc blend cubic structure. The UV-Visible absorption spectra of composite film reveal the blue shift in the band gap energy with respect to CdS bulk (2.42eV) material owing to quantum confinement effect. The Photoluminescence emission spectra show the green light emission at 510 nm arising from the defects states due to excess of cadmium or sulfur anion vacancies. Electroluminescence study indicates enhanced emission with low turn on voltage for higher loading of cadmium in polymer matrix due to increased oscillator strength. When higher electric field is applied, light emission start due to acceleration collision mechanism by charge carries inside the composite film.
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Liu, Xiaohong, Ming Li, Xuemei Zheng, Elias Retulainen, and Shiyu Fu. "Dual Light- and pH-Responsive Composite of Polyazo-Derivative Grafted Cellulose Nanocrystals." Materials 11, no. 9 (September 14, 2018): 1725. http://dx.doi.org/10.3390/ma11091725.
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As a type of functional group, azo-derivatives are commonly used to synthesize responsive materials. Cellulose nanocrystals (CNCs), prepared by acid hydrolysis of cotton, were dewatered and reacted with 2-bromoisobuturyl bromide to form a macro-initiator, which grafted 6-[4-(4-methoxyphenyl-azo) phenoxy] hexyl methacrylate (MMAZO) via atom transfer radical polymerization. The successful grafting was supported by Fourier transform infrared spectroscopy (FT-IR) and Solid magnetic resonance carbon spectrum (MAS 13C-NMR). The morphology and surface composition of the poly{6-[4-(4-methoxyphenylazo) phenoxy] hexyl methacrylate} (PMMAZO)-grafted CNCs were confirmed with Transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The grafting rate on the macro-initiator of CNCs was over 870%, and the polydispersities of branched polymers were narrow. The crystal structure of CNCs did not change after grafting, as determined by X-ray diffraction (XRD). The polymer PMMAZO improved the thermal stability of cellulose nanocrystals, as shown by thermogravimetry analysis (TGA). Then the PMMAZO-grafted CNCs were mixed with polyurethane and casted to form a composite film. The film showed a significant light and pH response, which may be suitable for visual acid-alkali measurement and reversible optical storage.
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Hartati, Nina, Tetty Kemala, Komar Sutriah, and Obie Farobie. "Compatibility of Celluloce Nanocrystal Modified Cetrimmonium Chloride (CTAC) in Polylactic Acid Matrix as Packaging Material." Jurnal Kimia Sains dan Aplikasi 22, no. 4 (July 20, 2019): 157–63. http://dx.doi.org/10.14710/jksa.22.4.157-163.
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Growth of population increases the consumption of nonbiodegradable plastic which causes waste buildup. Diversion of plastic material from nonbiodegradable material to biodegradable is an important alternatif. PLA is a plastic polymer that is easily degraded but very brittle. Palm oil waste containing oil palm empty bunches has the potential as a reinforcement material because the cellulose content is 30-40%. Minimizing size to nanoscale will increase the surface area and dispersion ability of cellulose dispersibility into the PLA polymer matrix, thus increasing compatibility in terms of and mechanical properties and surface morphology of the composite. Hydrolysis by strong acid and centrifugation at 5000 rpm succeeded in making cellulose nanocrystal with index of polidisperse 0.5 and average particle diameter of 7.967 nm. CTAC as a solubilizer and surface modifier agent successfully made interaction to cellulose nanocrystal as confirmed on absorption at wave number 2850 cm-1, 2960 cm-1 and 720 cm-1. Modified At the fixed CTAC concentration of 0.2 mol, the best mechanical properties of CNC-PLA composites were obtained in the composition ratio of 90: 10 with tensile strength of 26.295 MPa, elongation break of 68.18%, and Young modulus of 0.387 Gpa. The greater the CTAC added to nanocrystal cellulose, the lower the reinforcement value and the less reduction. Based on the results of morphology surface characterization, PLA surfaces required for degradation were obtained.
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Huo, Ying, Yingying Liu, Mingfeng Xia, Hong Du, Zhaoyun Lin, Bin Li, and Hongbin Liu. "Nanocellulose-Based Composite Materials Used in Drug Delivery Systems." Polymers 14, no. 13 (June 29, 2022): 2648. http://dx.doi.org/10.3390/polym14132648.
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Nanocellulose has lately emerged as one of the most promising “green” materials due to its unique properties. Nanocellulose can be mainly divided into three types, i.e., cellulose nanocrystals (CNCs), cellulose nanofibrils (CNFs), and bacterial cellulose (BC). With the rapid development of technology, nanocellulose has been designed into multidimensional structures, including 1D (nanofibers, microparticles), 2D (films), and 3D (hydrogels, aerogels) materials. Due to its adaptable surface chemistry, high surface area, biocompatibility, and biodegradability, nanocellulose-based composite materials can be further transformed as drug delivery carriers. Herein, nanocellulose-based composite material used for drug delivery was reviewed. The typical drug release behaviors and the drug release mechanisms of nanocellulose-based composite materials were further summarized, and the potential application of nanocellulose-based composite materials was prospected as well.
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Ma, Kangzhe, Xiang-Yun Du, Ya-Wen Zhang, and Su Chen. "In situ fabrication of halide perovskite nanocrystals embedded in polymer composites via microfluidic spinning microreactors." Journal of Materials Chemistry C 5, no. 36 (2017): 9398–404. http://dx.doi.org/10.1039/c7tc02847d.
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We demonstrated a green avenue to continuous mass production of stably fluorescent perovskite nanocrystal composite materials via a microfluidic spinning technique, potentially useful for application in WLEDs and displays.
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Smith, Ethan, Keith Hendren, James Haag, E. Foster, and Stephen Martin. "Functionalized Cellulose Nanocrystal Nanocomposite Membranes with Controlled Interfacial Transport for Improved Reverse Osmosis Performance." Nanomaterials 9, no. 1 (January 20, 2019): 125. http://dx.doi.org/10.3390/nano9010125.
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Thin-film nanocomposite membranes (TFNs) are a recent class of materials that use nanoparticles to provide improvements over traditional thin-film composite (TFC) reverse osmosis membranes by addressing various design challenges, e.g., low flux for brackish water sources, biofouling, etc. In this study, TFNs were produced using as-received cellulose nanocrystals (CNCs) and 2,2,6,6-Tetramethylpiperidine-1-oxyl (TEMPO)-oxidized cellulose nanocrystals (TOCNs) as nanoparticle additives. Cellulose nanocrystals are broadly interesting due to their high aspect ratios, low cost, sustainability, and potential for surface modification. Two methods of membrane fabrication were used in order to study the effects of nanoparticle dispersion on membrane flux and salt rejection: a vacuum filtration method and a monomer dispersion method. In both cases, various quantities of CNCs and TOCNs were incorporated into a polyamide TFC membrane via in-situ interfacial polymerization. The flux and rejection performance of the resulting membranes was evaluated, and the membranes were characterized via attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), transmission electron microscopy (TEM), and atomic force microscopy (AFM). The vacuum filtration method resulted in inconsistent TFN formation with poor nanocrystal dispersion in the polymer. In contrast, the dispersion method resulted in more consistent TFN formation with improvements in both water flux and salt rejection observed. The best improvement was obtained via the monomer dispersion method at 0.5 wt% TOCN loading resulting in a 260% increase in water flux and an increase in salt rejection to 98.98 ± 0.41% compared to 97.53 ± 0.31% for the plain polyamide membrane. The increased flux is attributed to the formation of nanochannels at the interface between the high aspect ratio nanocrystals and the polyamide matrix. These nanochannels serve as rapid transport pathways through the membrane, and can be used to tune selectivity via control of particle/polymer interactions.
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Bonavolontà, Carmela, Carla Aramo, Massimo Valentino, Giampiero Pepe, Sergio De Nicola, Gianfranco Carotenuto, Angela Longo, Mariano Palomba, Simone Boccardi, and Carosena Meola. "Graphene–polymer coating for the realization of strain sensors." Beilstein Journal of Nanotechnology 8 (January 3, 2017): 21–27. http://dx.doi.org/10.3762/bjnano.8.3.
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In this work we present a novel route to produce a graphene-based film on a polymer substrate. A transparent graphite colloidal suspension was applied to a slat of poly(methyl methacrylate) (PMMA). The good adhesion to the PMMA surface, combined with the shear stress, allows a uniform and continuous spreading of the graphite nanocrystals, resulting in a very uniform graphene multilayer coating on the substrate surface. The fabrication process is simple and yields thin coatings characterized by high optical transparency and large electrical piezoresitivity. Such properties envisage potential applications of this polymer-supported coating for use in strain sensing. The electrical and mechanical properties of these PMMA/graphene coatings were characterized by bending tests. The electrical transport was investigated as a function of the applied stress. The structural and strain properties of the polymer composite material were studied under stress by infrared thermography and micro-Raman spectroscopy.
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Gallardo, D. E., C. Bertoni, S. Dunn, N. Gaponik, and A. Eychmüller. "Cathodic and Anodic Material Diffusion in Polymer/Semiconductor-Nanocrystal Composite Devices." Advanced Materials 19, no. 20 (September 20, 2007): 3364–67. http://dx.doi.org/10.1002/adma.200700394.
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Tabassum, Madeeha, Qasim Zia, Jiashen Li, Muhammad Tauseef Khawar, Sameen Aslam, and Lei Su. "FAPbBr3 Perovskite Nanocrystals Embedded in Poly(L–lactic acid) Nanofibrous Membranes for Enhanced Air and Water Stability." Membranes 13, no. 3 (February 26, 2023): 279. http://dx.doi.org/10.3390/membranes13030279.
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Formamidinium lead bromide (FAPbBr3) nanocrystals have emerged as a powerful platform for optoelectronic applications due to their pure green photoluminescence (PL). However, their low colloidal stability under storage and operation reduces the potential use of FAPbBr3 perovskite nanocrystals (PeNCs) in various applications. In this study, we prepared the poly(L–lactic acid) (PLLA) nanofibrous membrane embedded with FAPbBr3 perovskite nanocrystals by electrospinning the perovskite and PLLA precursor solution. This is a simple and low-cost technique for the direct confinement of nano-sized functional materials in the continuous polymer nanofibres. PLLA as a polymer matrix provided a high surface framework to fully encapsulate the perovskite NCs. In addition, we found that FAPbBr3 PeNCs crystallize spontaneously inside the PLLA nanofibre. The resultant PLLA-FAPbBr3 nanofibrous membranes were stable and remained in the water for about 45 days without any evident decomposition. The results of this research support the idea of new possibilities for the production of air-stable FAPbBr3 PeNCs by forming a composite with PLLA polymer. The authors believe this study is a new milestone in the development of highly stable metal halide perovskite-based nanofibres, which allow for potential use in lasers, waveguides, and flexible energy harvesters.
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Tripathi, S. K., Jagdish Kaur, and Ramneek Kaur. "Photoluminescence Studies in II-VI Nanoparticles Embedded in Polymer Matrix." Defect and Diffusion Forum 357 (July 2014): 95–126. http://dx.doi.org/10.4028/www.scientific.net/ddf.357.95.
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Recently, organic-inorganic hybrid nanocomposite materials have been of great interest for their extraordinary performances due to the combination of the advantageous properties of polymers and the size dependent properties of nanocrystals (NCs). Interaction between the polymer matrix and nanocrystalline fillers produces wonderful features, viz. thermal, magnetic, mechanical, electrical and optical properties to these materials. Modern applications require a new design of responsive functional coatings which is capable of changing their properties in a controlled way. However, the synthesis of II-VI nanoparticles into the polymer matrix of its nanocomposites with adjustable sizes and protected from photo-oxidation is a big challenge to the scientific community. It is difficult to synthesize the highly enhanced luminescence in polymers and its semiconductor nanocomposite systems. Luminescence from the polymer embedded II-VI nanoparticles is greatly enhanced and better stability can be achieved from the composite compared to bulk materials. The formation of nanocomposites can be confirmed by photoluminescence (PL) spectroscopy. It is an important technique for determining the optical gap, purity, crystalline quality defects and analysis of the quantum confinement in these nanocomposite materials. In this paper, we have reviewed the present status of II-VI polymer nanocomposites from the photoluminescence studies point of view. We have also shown the results of the PL of these nanocomposite materials and the results will be compared with the reported literature by other groups.Contents of Paper
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Poulose, Aiswarya, Jyotishkumar Parameswaranpillai, Jinu Jacob George, Jineesh Ayippadath Gopi, Senthilkumar Krishnasamy, Midhun Dominic C. D., Nishar Hameed, Nisa V. Salim, Sabarish Radoor, and Natalia Sienkiewicz. "Nanocellulose: A Fundamental Material for Science and Technology Applications." Molecules 27, no. 22 (November 19, 2022): 8032. http://dx.doi.org/10.3390/molecules27228032.
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Recently, considerable interest has been focused on developing greener and biodegradable materials due to growing environmental concerns. Owing to their low cost, biodegradability, and good mechanical properties, plant fibers have substituted synthetic fibers in the preparation of composites. However, the poor interfacial adhesion due to the hydrophilic nature and high-water absorption limits the use of plant fibers as a reinforcing agent in polymer matrices. The hydrophilic nature of the plant fibers can be overcome by chemical treatments. Cellulose the most abundant natural polymer obtained from sources such as plants, wood, and bacteria has gained wider attention these days. Different methods, such as mechanical, chemical, and chemical treatments in combination with mechanical treatments, have been adopted by researchers for the extraction of cellulose from plants, bacteria, algae, etc. Cellulose nanocrystals (CNC), cellulose nanofibrils (CNF), and microcrystalline cellulose (MCC) have been extracted and used for different applications such as food packaging, water purification, drug delivery, and in composites. In this review, updated information on the methods of isolation of nanocellulose, classification, characterization, and application of nanocellulose has been highlighted. The characteristics and the current status of cellulose-based fiber-reinforced polymer composites in the industry have also been discussed in detail.
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Sanders, J. Elliott, Yousoo Han, Todd S. Rushing, and Douglas J. Gardner. "Electrospinning of Cellulose Nanocrystal-Filled Poly (Vinyl Alcohol) Solutions: Material Property Assessment." Nanomaterials 9, no. 5 (May 27, 2019): 805. http://dx.doi.org/10.3390/nano9050805.
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Poly (vinyl alcohol) (PVA) and cellulose nanocrystals (CNC) random composite mats were prepared using the electrospinning method. PVA/CNC mats were reinforced with weight concentrations of 0, 20 and 50% CNC (w/w) relative to PVA. Scanning electron microscopy was used to measure the fiber diameter, which ranged from 377 to 416 nm. Thermogravimetric analysis (TGA) confirmed the presence of CNC fibers in the mat fibers which were not visible by scanning electron microscope (SEM). Mechanical testing was conducted using ASTM D 638 on each sample group at 10 mm min−1. Neat PVA and PVA/CNC mats were heat treated at 170 °C for 2h hours, and the morphological structure was maintained with some fiber diameter reduction. Mechanical property results after heat treatment showed a decrease in tensile strength, an increase in tensile stiffness and a decrease in strain to yield (%). This effect was attributable to enhanced diffusion bonding of the mat fiber intersections. The CNC fibers also increased mat stiffness, and reduced strain to yield in non-treated mats. The use of CNCs show potential for compounding into bulk polymer composites as a reinforcement filler, and also show promise for chemical crosslinking attributable to the –OH groups on both the PVA, in addition to esterification of the vinyl group, and CNC.
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Chen, Shenggui, Junzhong Yang, Yong-Guang Jia, Bingheng Lu, and Li Ren. "A Study of 3D-Printable Reinforced Composite Resin: PMMA Modified with Silver Nanoparticles Loaded Cellulose Nanocrystal." Materials 11, no. 12 (December 3, 2018): 2444. http://dx.doi.org/10.3390/ma11122444.
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With the rapid application of light-curing 3D printing technology, the demand for high-performance polymer resins is increasing. Existing light-curable resins often have drawbacks limiting their clinical applications. This study aims to develop a new type of polymethyl methacrylate (PMMA) composite resins with enhanced mechanical properties, high antibacterial activities and excellent biocompatibilities. A series of reinforced composite resins were prepared by mechanically mixing PMMA with modified cellulose nanocrystals (CNCs), which were coated with polydopamine and decorated by silver nanoparticles (AgNPs) via Tollen reaction. The morphology of CNCs-Ag was observed by transmission electron microscopy and the formation of AgNPs on CNCs was confirmed by X-Ray photoelectron spectroscopy analyses. Functional groups in PMMA-CNCs-Ag composites were verified by Fourier Transform infrared spectroscopy (FTIR) spectroscopy. The mechanical assessment and scanning electron microscopy analysis suggested that the evenly distributed CNCs-AgNPs composite effectively improve mechanical properties of PMMA resin. Cytotoxicity assay and antibacterial activity tests indicated excellent biocompatibility and high antibacterial activities. Furthermore, PMMA with CNCs-AgNPs of 0.1 wt.% (PMMA-CNCs-AgNPs-0.1) possessed the most desirable mechanical properties owing to the homogeneous distribution of AgNPs throughout the resin matrix. This specific composite resin can be used as a functional dental restoration material with potential of other medical applications.
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Jo, Jaemin, Hyeyun Kim, So-Yeon Jeong, Chulhwan Park, Ha Soo Hwang, and Bonwook Koo. "Changes in Mechanical Properties of Polyhydroxyalkanoate with Double Silanized Cellulose Nanocrystals Using Different Organosiloxanes." Nanomaterials 11, no. 6 (June 11, 2021): 1542. http://dx.doi.org/10.3390/nano11061542.
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Polyhydroxyalkanoate (PHA) is a biodegradable plastic with great potential for tackling plastic waste and marine pollution issues, but its commercial applications have been limited due to its poor processability. In this study, surface-modified cellulose nanocrystals were used to improve the mechanical properties of PHA composites produced via a melt-extrusion process. Double silanization was conducted to obtain hydrophobically treated CNC-based fillers, using tetraethyl orthosilicate (TEOS) and methyltrimethoxysilane (MTMS). The morphology, particle size distributions, and surface characteristics of the silanized CNCs and their compatibility with a PHA polymer matrix differed by the organosiloxane treatment and drying method. It was confirmed that the double silanized CNCs had hydrophobic surface characteristics and narrow particle size distributions, and thereby showed excellent dispersibility in a PHA matrix. Adding hydrophobically treated CNCs to form a PHA composite, the elongation at break of the PHA composites was improved up to 301%, with little reduction of Young’s modulus, compared to pure PHA. Seemingly, the double silanized CNCs added played a similar role to a nucleation agent in the PHA composite. It is expected that such high ductility can improve the mechanical properties of PHA composites, making them more suitable for commercial applications.
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Baptista, Rosa M. F., Bruna Silva, João Oliveira, Vahideh B. Isfahani, Bernardo Almeida, Mário R. Pereira, Nuno Cerca, et al. "High Piezoelectric Output Voltage from Blue Fluorescent N,N-Dimethyl-4-nitroaniline Nano Crystals in Poly-L-Lactic Acid Electrospun Fibers." Materials 15, no. 22 (November 10, 2022): 7958. http://dx.doi.org/10.3390/ma15227958.
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N,N-dimethyl-4-nitroaniline is a piezoelectric organic superplastic and superelastic charge transfer molecular crystal that crystallizes in an acentric structure. Organic mechanical flexible crystals are of great importance as they stand between soft matter and inorganic crystals. Highly aligned poly-l-lactic acid polymer microfibers with embedded N,N-dimethyl-4-nitroaniline nanocrystals are fabricated using the electrospinning technique, and their piezoelectric and optical properties are explored as hybrid systems. The composite fibers display an extraordinarily high piezoelectric output response, where for a small stress of 5.0 × 103 Nm−2, an effective piezoelectric voltage coefficient of geff = 4.1 VmN−1 is obtained, which is one of the highest among piezoelectric polymers and organic lead perovskites. Mechanically, they exhibit an average increase of 67% in the Young modulus compared to polymer microfibers alone, reaching 55 MPa, while the tensile strength reaches 2.8 MPa. Furthermore, the fibers show solid-state blue fluorescence, important for emission applications, with a long lifetime decay (147 ns) lifetime decay. The present results show that nanocrystals from small organic molecules with luminescent, elastic and piezoelectric properties form a mechanically strong hybrid functional 2-dimensional array, promising for applications in energy harvesting through the piezoelectric effect and as solid-state blue emitters.
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Xin, Yi, Zijiang Jiang, Wenwen Li, Zonghao Huang, and Cheng Wang. "Preparation and characterization of in situ electrospun ZnS nanoparticles/PPV nanofibers." Pigment & Resin Technology 44, no. 2 (March 2, 2015): 74–78. http://dx.doi.org/10.1108/prt-09-2013-0084.
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Purpose – This paper aimed to prepare a kind of ZnS nanoparticles/poly(phenylene vinylene) (PPV) nanofibre and investigate its properties. Because the ZnS nanoparticles are important optoelectronic materials, their incorporation into one-dimensional (1D) nanoscale polymer matrices should be a meaningful subject for electrospinning. Design/methodology/approach – ZnS/PPV composite nanofibres with an average diameter of 600 nm were successfully prepared by a combination of the in situ method and electrospinning technique. The nanofibres were electrospun from Zn(CH3COO)2·2H2O and PPV precursor composite solution, and the ZnS/PPV fibres were obtained by exposure of the electrospun fibres to H2S gas to prepare ZnS nanoparticles in situ. Such fibres were characterised using X-ray Diffraction (XRD), Fourier transform infrared, transmission electron microscope (TEM), scanning electron microscope and photoluminescence (PL). The photoelectric properties of the fibres obtained were also investigated. Findings – XRD patterns proved that ZnS nanocrystals generated in the composite nanofibres. The TEM image showed that the nanocrystals were homogeneously dispersed in the nanofibres. The PL spectrum of ZnS/PPV composite nanofibres exhibited a blue shift relative to the PPV nanofibres. I-V curve of the single nanofibre device under 5.76 mW/cm2 light illumination showed that the composite nanofibres have good photoelectric properties. Research limitations/implications – The comparisons of advantages between ZnS/PPV nanofibres with similar nanofibres will be further expanded in a later research. Practical implications – Results demonstrate the promise of these novel nanostructures as ultraminiature photodetectors with the potential for integration into future hybrid nanophotonic devices and systems. Originality/value – The integration of inorganic semiconductor nanoparticles into organic conjugated polymers leads to composite materials with unique physical properties and important application potential. In this work, ZnS nanoparticles were introduced into PPV by an in situ method, so as to obtain a kind of novel 1D nanomaterials with good photoelectric properties.
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Yang, Heesun, Ji-Seung Lee, Seungmuk Bae, and Jin Ha Hwang. "Density-controlled growth of ZnO nanorods using ZnO nanocrystals-embedded polymer composite." Current Applied Physics 9, no. 4 (July 2009): 797–801. http://dx.doi.org/10.1016/j.cap.2008.07.016.
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LI, AI-DONG, JING TAN, JIN-BO CHENG, DI WU, and NAI-BEN MING. "PREPARATION AND CHARACTERIZATION OF POLED NANOCRYSTALS AND POLYMER COMPOSITE SrBi2Ta2O9/PC FILMS." Integrated Ferroelectrics 87, no. 1 (April 18, 2007): 59–66. http://dx.doi.org/10.1080/10584580601085461.
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Scano, Alessandra, Valentina Cabras, and Guido Ennas. "A New One-Pot Way to Prepare Enzyme-Containing Coordination Polymers by Sonochemistry." Journal of Nanoscience and Nanotechnology 21, no. 5 (May 1, 2021): 2935–38. http://dx.doi.org/10.1166/jnn.2021.19042.
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Enzyme-containing Coordination Polymers (CPs) were prepared by a one-pot sonochemical method, mixing Glucose Oxidase (GOx) enzyme, 4,4′-bipyridine as spacer ligand, and chloride zinc salt. The reaction took place in a very short time (a few minutes) with a minimum use of solvents compared to conventional methods. The obtained composite material, named GOx-[Zn(4,4′-bipy)Cl2]∞, resulted from embedding the GOx molecules into uniformly sized [Zn(4,4′-bipy)Cl2] nanocrystals. The structural and thermal characterization, confirmed that the adopted strategy allows the preparation of hybrid bio-nanomaterials in a very fast, facile and eco-friendly method, by simply synthesising the [Zn(4,4′-bipy)Cl2] nanocrystals in the presence of the enzyme.
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Fahma, F., I. Febiyanti, N. Lisdayana, I. W. Arnata, and D. Sartika. "Nanocellulose as a new sustainable material for various applications: a review." Archives of Materials Science and Engineering 2, no. 109 (June 1, 2021): 49–64. http://dx.doi.org/10.5604/01.3001.0015.2624.
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Purpose: This paper presents a comprehensive review of nanocellulose and its application in several applications, including composites, biomedical, and food packaging fields. Design/methodology/approach: General explanations about cellulose and nanocellulose have been described. Different types of nanocellulose (cellulose nanofibers, cellulose nanocrystals, bacterial nanocellulose) as well as their isolation processes (mechanical process, chemical process) have been reviewed. Several surface modifications have been explained to improve the dispersion of nanocellulose in non-polar polymers. The possible utilization of nanocellulose in composites, biomedical, and food packaging fields have also been analysed. Findings: This review presents three application fields at once, namely composites, biomedical, and food packaging fields. In the composite field, nanocellulose can be used as a reinforcing agent which increases the mehcnical properties such as tensile strength and toughness, and thermal stability of the final composites. In the biomedical field, nanocellulose is reinforced into hydrogel or composites which will be produced as tissue scaffolding, wound dressing, etc. It is found that the addition of nanocellulose can extend and control the drug release. While in the packaging field, nanocellulose is added into a biopolymer to improve the barrier properties and decrease the water and oxygen vapor transmission rates. Research limitations/implications: Nanocellulose has a hydrophilic nature, thus making it agglomerated and difficult to disperse in most non-polar polymers. Therefore, certain surface modification of nanocellulose are required prior to the preparation of composites or hydrogels.Practical implications: Further research regarding the toxicity of nanocellulose needs to be investigated, especially when applying it in the biomedical and food packaging fields. Originality/value: This review presents three application fields at once, namely composites, biomedical, and food packaging fields.
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Zhu, Ludan, Shuanglong Yuan, Jun Cheng, Long Chen, Chuanqi Liu, Hua Tong, Huidan Zeng, and Qiling Cheng. "Room Temperature In-Situ Synthesis of Inorganic Lead Halide Perovskite Nanocrystals Sol Using Ultraviolet Polymerized Acrylic Monomers as Solvent and Their Composites with High Stability." Applied Sciences 10, no. 9 (May 11, 2020): 3325. http://dx.doi.org/10.3390/app10093325.
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As a kind of promising optoelectrical material, all-inorganic perovskite nanocrystals CsPbX3 (X = Cl, Br, I) have attracted much attention, due to their excellent optoelectrical characteristics, in recent years. However, their synthesis approaches require rigorous conditions, including high temperature, eco-unfriendly solvent or complex post-synthesis process. Herein, to overcome these issues, we reported a novel facile room temperature in-situ strategy using ultraviolet polymerizable acrylic monomer as solvent to synthesis CsPbX3 nanocrystals without a complex post-synthesis process. In this strategy, adequate soluble precursors of Cs, Pb and Br and reaction terminating agent 3-aminopropyltriethoxysilane (APTES) were used. The obtained CsPbBr3 nanocrystals showed a high photoluminescence quantum yields (PLQY) of 87.5%. The corresponding polymer composites, by adding light initiator and oligomer under ultraviolet light radiation, performed excellent stability in light, air, moisture and high temperature. The reaction process and the effect of the reaction terminating agent have been investigated in detail. This strategy is a universal one for synthesizing CsPbX3 nanocrystals covering visible light range by introducing HCl and ZnI2.
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Kim, Wook Hyun, Jungyoun Bae, Kang-Pil Kim, and Sungho Woo. "Wavelength-Tunable and Water-Stable Cesium–Lead-Based All-Bromide Nanocrystal–Polymer Composite Films Using Ultraviolet-Curable Prepolymer as an Anti-Solvent." Polymers 14, no. 3 (January 19, 2022): 381. http://dx.doi.org/10.3390/polym14030381.
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All-inorganic metal halide perovskite nanocrystals (IPeNCs) have become one of the most promising luminescent materials for next-generation display and lighting technology owing to their excellent color expression ability. However, research on IPeNCs with stable blue emission is limited. In this paper, we report stable blue emissive all-bromide IPeNCs obtained through a modified ligand-assisted reprecipitation method using an ultraviolet (UV)-curable prepolymer as the anti-solvent at a low temperature. We found that the blue emission originates from quantum-confined CsPbBr3 nanoparticles formed together with the colorless wide-bandgap Cs4PbBr6 nanocrystals. When the temperature of the prepolymer was increased from 0 to 50 °C, CsPbBr3 nanoparticles became larger and more crystalline, thereby altering their emission color from blue to green. The synthesized all-bromide blue-emitting IPeNC solution remained stable for over 1 h. It also remained stable when it was mixed with the green-emitting IPeNC solution. By simply exposing the as-synthesized IPeNC–prepolymer solutions to UV light, we formed water-stable composite films that emitted red, green, blue, and white colors. We believe that this synthetic method can be used to develop color-emitting composite materials that are highly suitable for application as the color conversion films of full-color liquid crystal display backlight systems and lighting applications.
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Yuan, Quan, Xiao Dong Guo, Qi Xin Zheng, Ming Zhao, Zheng Qi Pan, Shun Guang Chen, and Da Ping Quan. "Bioinspired Growth of Hydroxyapatite Nanocrystals on PLGA- (PEG- ASP)n Scaffolds Modified with Oligopeptide Derived from BMP-2." Key Engineering Materials 334-335 (March 2007): 1261–64. http://dx.doi.org/10.4028/www.scientific.net/kem.334-335.1261.
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Natural bone is a typical example of an “organic matrix-mediated” biomineralization process which constituted of hydroxyapatite(HA) nanocrystals orderly grown in intimate contact with collagen fibers. Bone morphogenetic protein 2 (BMP2) is the most powerful osteogenic factor. But it is extremely difficult to be manufactured in large scale. In previous study, we have designed a novel oligopeptide (P24) derived from BMP2 knuckle epitope and it contained abundant Asp(aspartic acid) and phosphorylated Ser(serine) which may be helpful for self-assambly biomineralization and osteogenesis. Previous In vivo experiments have shown that this novel oligopeptide had excellent osteoinductive and ectopic bone formation property which was similar to that of BMP2. In this study, PLGA-(PEG-ASP)n scaffolds were modified with P24 and a new biomimetic bone tissue engineering scaffold material with enhanced bioactivity was synthesized by a biologically inspired mineralization approach. Peptide P24 was introduced into PLGA-(PEG-ASP)n scaffolds using cross-linkers. Then the P24 modified scaffolds and the simple PLGA-(PEG-ASP)n scaffolds were incubated in modified simulated body fluid (mSBF) for 10 days. Growth of HA nanocrystals on the materials was confirmed by observation SEM and measurements EDS and XRD. SEM analysis demonstrated the well growth of bonelike HA nanocrystals on P24 modified PLGA-(PEG-ASP)n scaffolds than that of the control scaffolds. The main component of mineral of the P24 modified scaffolds was hydroxyapatite containing low crystalline nanocrystals, and the Ca/P ratio was nearly 1.60, similar to that of natural bone, while that of the control scaffolds was 1.52. The introduction of peptide P24 into PLGA- (PEG- ASP)n copolymer provides abundant active sites to mediate the nucleation and self- ssembling of HA nanocrystals in mSBF. the resulted peptide P24 modified- HA/PLGA- (PEG- ASP)n composite shows some features of natural bone both in main composition and and hierarchical microstructure. This biomimetic treatment provides a simple method for surface functionalization and subsequent biomineralization on biodegradable polymer scaffolds for tissue engineering.
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Chou, Chun-Tu, Shih-Chen Shi, and Chih-Kuang Chen. "Sandwich-Structured, Hydrophobic, Nanocellulose-Reinforced Polyvinyl Alcohol as an Alternative Straw Material." Polymers 13, no. 24 (December 18, 2021): 4447. http://dx.doi.org/10.3390/polym13244447.
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An environmentally friendly, hydrophobic polyvinyl alcohol (PVA) film was developed as an alternative to commercial straws for mitigating the issue of plastic waste. Nontoxic and biodegradable cellulose nanocrystals (CNCs) and nanofibers (CNFs) were used to prepare PVA nanocomposite films by blade coating and solution casting. Double-sided solution casting of polyethylene-glycol–poly(lactic acid) (PEG–PLA) + neat PLA hydrophobic films was performed, which was followed by heat treatment at different temperatures and durations to hydrophobize the PVA composite films. The hydrophobic characteristics of the prepared composite films and a commercial straw were compared. The PVA nanocomposite films exhibited enhanced water vapor barrier and thermal properties owing to the hydrogen bonds and van der Waals forces between the substrate and the fillers. In the sandwich-structured PVA-based hydrophobic composite films, the crystallinity of PLA was increased by adjusting the temperature and duration of heat treatment, which significantly improved their contact angle and water vapor barrier. Finally, the initial contact angle and contact duration (at the contact angle of 20°) increased by 35% and 40%, respectively, which was a significant increase in the service life of the biodegradable material-based straw.
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Liu, W. C., A. D. Li, J. Tan, S. Huang, D. Wu, Z. R. Shen, H. Ye, and N. B. Ming. "Preparation and Electro-Optic Properties of Poled Nanocrystals and Polymer Composite BaTiO3/PC Films." Ferroelectrics 329, no. 1 (December 2005): 79–83. http://dx.doi.org/10.1080/00150190500315616.
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Feng, Chiao, and Sheng-Sheng Yu. "3D Printing of Thermal Insulating Polyimide/Cellulose Nanocrystal Composite Aerogels with Low Dimensional Shrinkage." Polymers 13, no. 21 (October 20, 2021): 3614. http://dx.doi.org/10.3390/polym13213614.
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Polyimide (PI)-based aerogels have been widely applied to aviation, automobiles, and thermal insulation because of their high porosity, low density, and excellent thermal insulating ability. However, the fabrication of PI aerogels is still restricted to the traditional molding process, and it is often challenging to prepare high-performance PI aerogels with complex 3D structures. Interestingly, renewable nanomaterials such as cellulose nanocrystals (CNCs) may provide a unique approach for 3D printing, mechanical reinforcement, and shape fidelity of the PI aerogels. Herein, we proposed a facile water-based 3D printable ink with sustainable nanofillers, cellulose nanocrystals (CNCs). Polyamic acid was first mixed with triethylamine to form an aqueous solution of polyamic acid ammonium salts (PAAS). CNCs were then dispersed in the aqueous PAAS solution to form a reversible physical network for direct ink writing (DIW). Further freeze-drying and thermal imidization produced porous PI/CNC composite aerogels with increased mechanical strength. The concentration of CNCs needed for DIW was reduced in the presence of PAAS, potentially because of the depletion effect of the polymer solution. Further analysis suggested that the physical network of CNCs lowered the shrinkage of aerogels during preparation and improved the shape-fidelity of the PI/CNC composite aerogels. In addition, the composite aerogels retained low thermal conductivity and may be used as heat management materials. Overall, our approach successfully utilized CNCs as rheological modifiers and reinforcement to 3D print strong PI/CNC composite aerogels for advanced thermal regulation.
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Li, Minjie, Hao Zhang, Junhu Zhang, Chunlei Wang, Kun Han, and Bai Yang. "Easy preparation and characterization of highly fluorescent polymer composite microspheres from aqueous CdTe nanocrystals." Journal of Colloid and Interface Science 300, no. 2 (August 2006): 564–68. http://dx.doi.org/10.1016/j.jcis.2006.04.031.
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Mármol, Gonzalo, Christian Gauss, and Raul Fangueiro. "Potential of Cellulose Microfibers for PHA and PLA Biopolymers Reinforcement." Molecules 25, no. 20 (October 13, 2020): 4653. http://dx.doi.org/10.3390/molecules25204653.
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Cellulose nanocrystals (CNC) have attracted the attention of many engineering fields and offered excellent mechanical and physical properties as polymer reinforcement. However, their application in composite products with high material demand is complex due to the current production costs. This work explores the use of cellulose microfibers (MF) obtained by a straightforward water dispersion of kraft paper to reinforce polyhydroxyalkanoate (PHA) and polylactic acid (PLA) films. To assess the influence of this type of filler material on the properties of biopolymers, films were cast and reinforced at different scales, with both CNC and MF separately, to compare their effectiveness. Regarding mechanical properties, CNC has a better reinforcing effect on the tensile strength of PLA samples, though up to 20 wt.% of MF may also lead to stronger PLA films. Moreover, PHA films reinforced with MF are 23% stronger than neat PHA samples. This gain in strength is accompanied by an increment of the stiffness of the material. Additionally, the addition of MF leads to an increase in the crystallinity of PHA that can be controlled by heat treatment followed by quenching. This change in the crystallinity of PHA affects the hygroscopicity of PHA samples, allowing the modification of the water barrier properties according to the required features. The addition of MF to both types of polymers also increases the surface roughness of the films, which may contribute to obtaining better interlaminar bonding in multi-layer composite applications. Due to the partial lignin content in MF from kraft paper, samples reinforced with MF present a UV blocking effect. Therefore, MF from kraft paper may be explored as a way to introduce high fiber concentrations (up to 20 wt.%) from other sources of recycled paper into biocomposite manufacturing with economic and technical benefits.
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Saatsakis, George, Nektarios Kalyvas, Christos Michail, Konstantinos Ninos, Athanasios Bakas, Christina Fountzoula, Ioannis Sianoudis, et al. "Optical Characteristics of ZnCuInS/ZnS (Core/Shell) Nanocrystal Flexible Films Under X-Ray Excitation." Crystals 9, no. 7 (July 4, 2019): 343. http://dx.doi.org/10.3390/cryst9070343.
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The aim of this article is to evaluate optical characteristics, such as the intrinsic conversion efficiency and the inherent light propagation efficiency of three polymethyl methacrylate (PMMA)/methyl methacrylate (MMA) composite ZnCuInS/ZnS (core/shell) nanocrystal flexible films. The concentrations of these were 100 mg/mL, 150 mg/mL, and 250 mg/mL, respectively. Composite films were prepared by homogeneously diluting dry powder quantum dot (QD) samples in toluene and subsequently mixing these with a PMMA/MMA polymer solution. The absolute luminescence efficiency (AE) of the films was measured using X-ray excitation. A theoretical model describing the optical photon propagation in scintillator materials was used to calculate the fraction of the generated optical photons passed through the different material layers. Finally, the intrinsic conversion efficiency was calculated by considering the QD quantum yield and the optical photon emission spectrum.
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Going, Ryan J., Dan E. Sameoto, and Cagri Ayranci. "Cellulose Nanocrystals: Dispersion in Co-Solvent Systems and Effects on Electrospun Polyvinylpyrrolidone Fiber Mats." Journal of Engineered Fibers and Fabrics 10, no. 3 (September 2015): 155892501501000. http://dx.doi.org/10.1177/155892501501000310.
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This study reports a method to achieve dispersion of freeze-dried Cellulose nanocrystals (CNCs) with polyvinylpyrrolidone (PVP) in a water-methanol co-solvent system using purely mechanical means; in this case, magnetic stirring and sonication. During this study, no chemical modifiers or surfactants of any kind were added during the dispersion process as they increase the cost and duration of the manufacturing process for CNC reinforced composites and nanocomposites. The effect of CNC loading (0-20wt% of PVP) and preparation method on solution viscosity, dispersion, and mechanical properties of electrospun PVP/CNC nanocomposite fiber mats were examined. In particular, this study demonstrates that pre-dispersion of the hydrophilic CNCs in pure deionized water before the addition of methanol and PVP is critical to improving dispersion and achieving greater homogeneity of the system. All samples were examined for birefringence by polarized light microscopy, which was correlated to the level of CNC dispersion within the polymer matrix. The effect of CNC loading on the mechanical properties of the composite mats was investigated via tensile testing. Humidity was identified as an important factor affecting the PVP nanofiber morphology and strength, though its effects were not characterized in this study.
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Guan, Bu Yuan, Le Yu, Ju Li, and Xiong Wen (David) Lou. "A universal cooperative assembly-directed method for coating of mesoporous TiO2 nanoshells with enhanced lithium storage properties." Science Advances 2, no. 3 (March 2016): e1501554. http://dx.doi.org/10.1126/sciadv.1501554.
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TiO2 is exceptionally useful, but it remains a great challenge to develop a universal method to coat TiO2 nanoshells on different functional materials. We report a one-pot, low-temperature, and facile method that can rapidly form mesoporous TiO2 shells on various inorganic, organic, and inorganic-organic composite materials, including silica-based, metal, metal oxide, organic polymer, carbon-based, and metal-organic framework nanomaterials via a cooperative assembly-directed strategy. In constructing hollow, core-shell, and yolk-shell geometries, both amorphous and crystalline TiO2 nanoshells are demonstrated with excellent control. When used as electrode materials for lithium ion batteries, these crystalline TiO2 nanoshells composed of very small nanocrystals exhibit remarkably long-term cycling stability over 1000 cycles. The electrochemical properties demonstrate that these TiO2 nanoshells are promising anode materials.
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Natarajan, Bharath, and Jeffrey W. Gilman. "Bioinspired Bouligand cellulose nanocrystal composites: a review of mechanical properties." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 376, no. 2112 (December 25, 2017): 20170050. http://dx.doi.org/10.1098/rsta.2017.0050.
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The twisted plywood, or Bouligand, structure is the most commonly observed microstructural motif in natural materials that possess high mechanical strength and toughness, such as that found in bone and the mantis shrimp dactyl club. These materials are isotropically toughened by a low volume fraction of soft, energy-dissipating polymer and by the Bouligand structure itself, through shear wave filtering and crack twisting, deflection and arrest. Cellulose nanocrystals (CNCs) are excellent candidates for the bottom-up fabrication of these structures, as they naturally self-assemble into ‘chiral nematic’ films when cast from solutions and possess outstanding mechanical properties. In this article, we present a review of the fabrication techniques and the corresponding mechanical properties of Bouligand biomimetic CNC nanocomposites, while drawing comparison to the performance standards set by tough natural composite materials. This article is part of a discussion meeting issue ‘New horizons for cellulose nanotechnology’.
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Mavropoulos, Elena, Maria Helena Rocha-Leão, Nilce C. C. da Rocha, Marcelo H. Prado da Silva, and Alexandre Malta Rossi. "Hydroxyapatite-alginate composite for lead removal in artificial gastric fluid." Journal of Materials Research 22, no. 12 (December 2007): 3371–77. http://dx.doi.org/10.1557/jmr.2007.0419.
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Millimetric spherical beads of a biocompatible composite were produced from sodium alginate, a natural polysaccharide, and nanostructured hydroxyapatite (HA). It was shown that the composite was effective in the removal of lead ions and lead phosphate nanoparticles from high-contaminated simulated gastric fluid. X-ray diffraction spectroscopy and scanning electron microscopy analyses performed on HA–alginate beads after the Pb2+ uptake showed that nanocrystals of a lead phosphate, [Pb10–xCax(PO4)6Cl2], were precipitated on the bead surface. The cross-linked polymer chain had a double role: (i) keep Pb2+ ions and lead phosphate nanoparticles bounded to the bead surface, preventing their bioavailability in stomach fluid; and (ii) delay HA dissolution in the acidic conditions of the stomach, assuring that an excess of Ca2+ will not be released to simulated gastric fluid. Desorption experiments in simulated enteric fluid revealed that lead remained immobilized in the calcium phosphate phase in the intestinal tract. These results indicate HA–alginate composite as a potential system for heavy metals removal from contaminated gastric and enteric human fluids, minimizing its adsorption by the human body.
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Shan, Chengwei, Zhuang Wang, Zhaojin Wang, Teng Wang, Dou Luo, Kai Wang, Xiao Wei Sun, and Aung Ko Ko Kyaw. "Screen printing strategy for fabricating flexible crystallized perovskite nanocomposite patterns with high photoluminescence." Flexible and Printed Electronics 7, no. 1 (March 1, 2022): 015010. http://dx.doi.org/10.1088/2058-8585/ac5fb5.
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Abstract Organohalide perovskites have been witnessed as an emerging class of solution processable semiconductor with huge potential for applications in optoelectronic devices. However, a low-cost and high-yield patterning of these materials needs to be further improved. Herein, we demonstrated a facile approach to pattern perovskite nanocrystals embedded in polymer matrix by screen printing strategy. Importantly, this strategy achieves a champion photoluminescence quantum yield up to 96.5% and exhibited an intense green emission band centered at 517 nm with narrow full width at half-maximum of 20 nm. In addition, the composite films show an extraordinary stability in various environments, such as air, water, high temperature (80 °C), and Ultraviolet -radiation. The photoluminescence intensity of composite films decreases only 1.4% after being stored in air with 85% relative humidity for 3 months and remains 81.6% of initial values after being submerged in water for 3 months. Finally, we printed high-resolution patterns of 175 µm, demonstrating that the screen printing is very promising for patterning perovskite composite microarrays.