Articles de revues : « POLYMER OXIDE »

1

Kausar, Ayesha. « Conjugated Polymer/Graphene Oxide Nanocomposites—State-of-the-Art ». Journal of Composites Science 5, n^o 11 (5 novembre 2021) : 292. http://dx.doi.org/10.3390/jcs5110292.

Texte intégral

Résumé :

Graphene oxide is an imperative modified form of graphene. Similar to graphene, graphene oxide has gained vast interest for the myriad of industrial applications. Conjugated polymers or conducting polymers are well known organic materials having conducting backbone. These polymers have semiconducting nature due to π-conjugation along the main chain. Doping and modification have been used to enhance the electrical conductivity of the conjugated polymers. The nanocomposites of the conjugated polymers have been reported with the nanocarbon nanofillers including graphene oxide. This review essentially presents the structure, properties, and advancements in the field of conducting polymer/graphene oxide nanocomposites. The facile synthesis, processability, and physical properties of the polymer/graphene oxide nanocomposites have been discussed. The conjugated polymer/graphene oxide nanocomposites have essential significance for the supercapacitors, solar cells, and anti-corrosion materials. Nevertheless, the further advanced properties and technical applications of the conjugated polymer/graphene oxide nanocomposites need to be explored to overcome the challenges related to the high performance.

Styles APA, Harvard, Vancouver, ISO, etc.

2

Tran, Vinh Van, Truong Thi Vu Nu, Hong-Ryun Jung et Mincheol Chang. « Advanced Photocatalysts Based on Conducting Polymer/Metal Oxide Composites for Environmental Applications ». Polymers 13, n^o 18 (8 septembre 2021) : 3031. http://dx.doi.org/10.3390/polym13183031.

Texte intégral

Résumé :

Photocatalysts provide a sustainable method of treating organic pollutants in wastewater and converting greenhouse gases. Many studies have been published on this topic in recent years, which signifies the great interest and attention that this topic inspires in the community, as well as in scientists. Composite photocatalysts based on conducting polymers and metal oxides have emerged as novel and promising photoactive materials. It has been demonstrated that conducting polymers can substantially improve the photocatalytic efficiency of metal oxides owing to their superior photocatalytic activities, high conductivities, and unique electrochemical and optical properties. Consequently, conducting polymer/metal oxide composites exhibit a high photoresponse and possess a higher surface area allowing for visible light absorption, low recombination of charge carriers, and high photocatalytic performance. Herein, we provide an overview of recent advances in the development of conducting polymer/metal oxide composite photocatalysts for organic pollutant degradation and CO2 conversion through photocatalytic processes.

Styles APA, Harvard, Vancouver, ISO, etc.

3

Tanaka, Takeshi, Osamu Terakado et Masahiro Hirasawa. « Thermochemical Approach for Screening of Alternative Metal Oxides as a Flame Retardant of Modacrylic Fiber ». High Temperature Materials and Processes 36, n^o 3 (1 mars 2017) : 233–42. http://dx.doi.org/10.1515/htmp-2015-0140.

Texte intégral

Résumé :

AbstractIn the view of the exploring novel flame retardants for polymers, modacrylic fibers, which consist of acrylonitrile and vinylidene dichloride, containing metal oxide have been investigated by thermogravimetric–mass spectrometry (TG-MS) analysis. It was found that, among the examined oxides, germanium and antimony oxides formed the corresponding volatile chlorides through the reactions of oxides with hydrogen chloride formed during thermal decomposition of the polymer. The results have been discussed in the framework of thermochemistry. Based on the equilibrium calculation of the polymer–oxide mixture, the predominance diagrams of the M-O-Cl systems (M = Sb and Ge) show that the chlorides are the most stable phases at 573 K, at which temperature the major decomposition of the polymer starts. These results suggest that GeO2 would be a possible candidate of a flame retardant for chlorinated polymers. However, combustion experiments revealed an insufficient performance of the oxide. The inductively coupled plasma with atomic emission spectroscopy (ICP-AES) analysis showed the reactivity of GeO2 for HCl was inferior to that of Sb2O3, and X-ray fluorescence spectrometer (XRF) analysis of the solid thermal decomposition products showed that the evaporation of germanium was less intense than that of the conventional antimony system. This result is presumably due to the smaller rate of the chlorination of GeO2 than that of Sb2O3.

Styles APA, Harvard, Vancouver, ISO, etc.

4

Chrissopoulou, Kiriaki, Krystalenia Androulaki, Massimiliano Labardi et Spiros H. Anastasiadis. « Static and Dynamic Behavior of Polymer/Graphite Oxide Nanocomposites before and after Thermal Reduction ». Polymers 13, n^o 7 (25 mars 2021) : 1008. http://dx.doi.org/10.3390/polym13071008.

Texte intégral

Résumé :

Nanocomposites of hyperbranched polymers with graphitic materials are investigated with respect to their structure and thermal properties as well as the dynamics of the polymer probing the effect of the different intercalated or exfoliated structure. Three generations of hyperbranched polyester polyols are mixed with graphite oxide (GO) and the favorable interactions between the polymers and the solid surfaces lead to intercalated structure. The thermal transitions of the confined chains are suppressed, whereas their dynamics show similarities and differences with the dynamics of the neat polymers. The three relaxation processes observed for the neat polymers are observed in the nanohybrids as well, but with different temperature dependencies. Thermal reduction of the graphite oxide in the presence of the polymer to produce reduced graphite oxide (rGO) reveals an increase in the reduction temperature, which is accompanied by decreased thermal stability of the polymer. The de-oxygenation of the graphite oxide leads to the destruction of the intercalated structure and to the dispersion of the rGO layers within the polymeric matrix because of the modification of the interactions between the polymer chains and the surfaces. A significant increase in the conductivity of the resulting nanocomposites, in comparison to both the polymers and the intercalated nanohybrids, indicates the formation of a percolated rGO network.

Styles APA, Harvard, Vancouver, ISO, etc.

5

Ahadzade, Sh M., I. A. Vakulenko et Kh Asgarov. « Factors Influence on Electrophysical Parameters of the Composite Varistors ». Science and Transport Progress, n^o 1(101) (14 mars 2023) : 29–36. http://dx.doi.org/10.15802/stp2023/283013.

Texte intégral

Résumé :

Purpose. Evaluation influence structural state polymer phase on the response voltage and coefficient nonlinearity of a multilayer varistor based on zinc oxide. Methodology. Zinc oxide consisted of 97% zinc oxide and 3% total oxides of Bi2O3, Co3O4, MnO2, B2O3, SbO3, ZrO2, Al2O3. At a temperature of 1573°K, the synthesis of semiconductor ceramics based on Zinc oxide was carried out. For composite of thermoplastic polymers and Zinc oxide, non-polar and polar polymers, high pressure polyethylene and polyvinylidene fluoride were used. The composites were obtained by hot pressing at the melting temperature of the polymer phase and a pressure of 15 MPa. After that, using silver paste, measuring electrodes 10 mm in diameter were applied to the surface of the synthesized samples, and then current–voltage characteristics were measured. Modification of composites under action of gas-discharge plasma was carried out in a special cell that creates a dielectric-gas-composite system. The structure of the composites was studied by X-ray diffraction analysis and IR spectroscopy. Findings. The obtained experimental results show that the size of the particles of the inorganic phase significantly affects the current-voltage characteristics of the composite varistor: at a given thickness of the composite varistor, the operation voltage decreases markedly, and the nonlinearity coefficient increases. Numerous experimental results obtained by us show that the impact of electric discharge plasma on the polymer Zinc oxide-composite leads to a significant change in the permittivity and the concentration of local levels at the interface of the composite. The results research showed that effect electrical plasma on the opening voltage depends on the polarity of polymer matrices. Moreover, plasma processing itself significantly changes the structure of the polymer phase at composite. Originality. The magnitude of the potential barrier at phase boundary is mainly determined by the volume fraction and size of the main structural element of ZnO ceramics. Changing the structural state of the polymer matrix allows the adjust response voltage and coefficient nonlinearity of volt-ampere characteristic of the multilayer varistor. Practical value. The discovered development of electron-ion processes at polymer phase of the varistor indicates the need to take into account change in its service characteristics from the duration and intensity of use. The result obtained has a certain practical significance, since it indicates not only the reason for the change in properties, but also the need to develop measures to increase the service life of the varistor.

Styles APA, Harvard, Vancouver, ISO, etc.

6

Barick, Barun K., Neta Shomrat, Uri Green, Zohar Katzman et Tamar Segal-Peretz. « Fabrication of Nanoscale Oxide Textured Surfaces on Polymers ». Polymers 13, n^o 13 (3 juillet 2021) : 2209. http://dx.doi.org/10.3390/polym13132209.

Texte intégral

Résumé :

Nanoscale textured surfaces play an important role in creating antibacterial surfaces, broadband anti-reflective properties, and super-hydrophobicity in many technological systems. Creating nanoscale oxide textures on polymer substrates for applications such as ophthalmic lenses and flexible electronics imposes additional challenges over conventional nanofabrication processes since polymer substrates are typically temperature-sensitive and chemically reactive. In this study, we investigated and developed nanofabrication methodologies to create highly ordered oxide nanostructures on top of polymer substrates without any lithography process. We developed suitable block copolymer self-assembly, sequential infiltration synthesis (SIS), and reactive ion etching (RIE) for processes on polymer substrates. Importantly, to prevent damage to the temperature-sensitive polymer and polymer/oxide interface, we developed the process to be entirely performed at low temperatures, that is, below 80 °C, using a combination of UV crosslinking, solvent annealing, and modified SIS and RIE processes. In addition, we developed a substrate passivation process to overcome reactivity between the polymer substrate and the SIS precursors as well as a high precision RIE process to enable deep etching into the thermally insulated substrate. These methodologies widen the possibilities of nanofabrication on polymers.

Styles APA, Harvard, Vancouver, ISO, etc.

7

El-Said, Waleed A., Muhammad Abdelshakour, Jin-Ha Choi et Jeong-Woo Choi. « Application of Conducting Polymer Nanostructures to Electrochemical Biosensors ». Molecules 25, n^o 2 (12 janvier 2020) : 307. http://dx.doi.org/10.3390/molecules25020307.

Texte intégral

Résumé :

Over the past few decades, nanostructured conducting polymers have received great attention in several application fields, including biosensors, microelectronics, polymer batteries, actuators, energy conversion, and biological applications due to their excellent conductivity, stability, and ease of preparation. In the bioengineering application field, the conducting polymers were reported as excellent matrixes for the functionalization of various biological molecules and thus enhanced their performances as biosensors. In addition, combinations of metals or metal oxides nanostructures with conducting polymers result in enhancing the stability and sensitivity as the biosensing platform. Therefore, several methods have been reported for developing homogeneous metal/metal oxide nanostructures thin layer on the conducting polymer surfaces. This review will introduce the fabrications of different conducting polymers nanostructures and their composites with different shapes. We will exhibit the different techniques that can be used to develop conducting polymers nanostructures and to investigate their chemical, physical and topographical effects. Among the various biosensors, we will focus on conducting polymer-integrated electrochemical biosensors for monitoring important biological targets such as DNA, proteins, peptides, and other biological biomarkers, in addition to their applications as cell-based chips. Furthermore, the fabrication and applications of the molecularly imprinted polymer-based biosensors will be addressed in this review.

Styles APA, Harvard, Vancouver, ISO, etc.

8

Kashytskyi, V. P., O. L. Sadova, M. D. Melnychuk, G. I. Golodyuk et O. B. Klymovets. « Structuring of Modified Epoxy Composite Materials by Infrared Spectroscopy ». Journal of Engineering Sciences 10, n^o 1 (2023) : C9—C16. http://dx.doi.org/10.21272/jes.2023.10(1).c2.

Texte intégral

Résumé :

A comparative evaluation of the structuring processes of the epoxy polymer system with epoxy polymers modified with polyvinyl chloride solution and epoxy composites filled with finely dispersed titanium oxide powder was carried out. Analysis of the infrared (IR) absorption spectra of the studied epoxy polymer and epoxy composite materials showed the presence of deformation and valence vibrations of certain groups of atoms. The oscillations of groups of atoms with double bonds and regions of existence of triple bonds were also revealed. In the region of high frequencies, absorption bands correspond to valence vibrations of groups containing a hydrogen atom. The presence of triple bonds in the epoxy polymer system was determined, indicating unreacted functional groups. This fact corresponds to the low content of the gel fraction of unmodified epoxy polymers after heat treatment and indicates the formation of a system with insufficient chemical bonds. The absorption bands of the epoxy composite material filled with titanium oxide powder are characterized by a lower optical density and a larger peak area compared to the bands of the unmodified epoxy polymer, which indicates the formation of a higher number of crosslinking nodes of the epoxy composite material. The introduction of polyvinyl chloride into the composition of the epoxy polymer system increases the degree of structuring of epoxy polymers. However, a smaller number of formed chemical bonds of the modified epoxy polymer was recorded compared to epoxy composites containing titanium oxide particles. The highest degree of structuring is provided in polyvinyl chloride-modified epoxy composites containing titanium oxide powder due to intensive structuring and formation of double and triple bonds.

Styles APA, Harvard, Vancouver, ISO, etc.

9

Florjanczyk, Zbigniew, Ewa Zygadlo-Monikowska, Justyna Ostrowska et Anita Frydrych. « Solid polymer electrolytes based on ethylene oxide polymers ». Polimery 59, n^o 01 (janvier 2014) : 80–87. http://dx.doi.org/10.14314/polimery.2014.080.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

10

Yu, Mei Hui, Hui Min Meng et Ying Xue. « Nano-Mesh Structured Mn-Based Oxide/Conducting Polymer Composite Electrode for Supercapacitor ». Materials Science Forum 859 (mai 2016) : 104–8. http://dx.doi.org/10.4028/www.scientific.net/msf.859.104.

Texte intégral

Résumé :

In this work, modified nano-mesh structured Mn-based oxide electrode material and the supercapacitors are researched. Three types of conducting polymers, i.e. polyaniline (PANI), polypyrrole (PPy) and polythiophene (PTs) are considered to modify Mn-based oxide electrodes. The results of field emission scanning electron microscope show that conducting polymer film can form porous structure on Mn-based oxide electrode, this special structure is beneficial to the improvement of specific surface area, so that the specific capacitance can be increased. The specific capacitance of the supercapacitors assembled by Mn-based oxide/conducting polymer composite electrodes are tested, resulting that the maximum initial specific capacitance is 843 F g-1, cycle life is 105 times. Compared to supercapacitors assembled by general Mn-based oxide electrodes, this Mn-based oxide/conducting polymer material electrode can improve the specific capacitance up to 1.4~1.9 times, and the conductivity and cycle stability can be increased at the same time.

Styles APA, Harvard, Vancouver, ISO, etc.

11

Hashim, A., et A. Hadi. « Novel Lead Oxide Polymer Nanocomposites for Nuclear Radiation Shielding Applications ». Ukrainian Journal of Physics 62, n^o 11 (décembre 2017) : 978–83. http://dx.doi.org/10.15407/ujpe62.11.0978.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

12

Colletti, Ronald F., Harvey S. Gold et Cecil Dybowski. « Characterization of the Adsorption of Poly(Acrylamide), Poly(4-methoxystyrene), and Poly(Acrylic Acid) on Aluminum Oxide by Inelastic Electron Tunneling Spectroscopy ». Applied Spectroscopy 41, n^o 7 (septembre 1987) : 1185–89. http://dx.doi.org/10.1366/0003702874447725.

Texte intégral

Résumé :

The adsorptions of polystyrene, poly(methoxystyrene), poly(acrylamide), and poly(acrylic acid) on aluminum oxide are investigated with inelastic electron tunneling spectroscopy. Comparison with infrared data for thin polymer films of the polymer samples gives insight into the adsorbed polymer configuration. Data indicate that poly(styrene) is weakly physisorbed to aluminum oxide, while poly(methoxystyrene), poly(acrylamide), and poly(acrylic acid) react to form strong bonds with the oxide surface. On the basis of this data, adsorption mechanisms are suggested for each of the polymers. Poly(acrylamide) adsorbs via a protonation of the amine group by the surface hydroxyl groups. Poly(4-methoxystyrene) forms a phenolate ion and can react further with the aluminum surface centers. Poly(acrylic acid) adsorbs to the oxide surface in a manner analogous to that of small organic acids such as the carboxylate ion.

Styles APA, Harvard, Vancouver, ISO, etc.

13

Arshad Fadhil Kadhim et Ahmed Hashim. « Recent review on metal oxides nanostructures doped polystyrene for biological and industrial applications ». World Journal of Advanced Research and Reviews 17, n^o 3 (30 mars 2023) : 412–23. http://dx.doi.org/10.30574/wjarr.2023.17.3.0404.

Texte intégral

Résumé :

Polymers have many applications in various medical and industrial approaches. One of these polymers is polystyrene which has special properties to be considered as promising material in different optics, biomedical, and electronics fields. The addition of metal oxides nanoparticles to polystyrene have huge applications in different approaches. This article includes a recent review on metal oxide NPs doped polymer (such as polystyrene). The previous studies demonstrated the polystyrene nanocomposites comprised numerous applications in the electronics, sensors, optical optoelectronics, and biomedical fields.

Styles APA, Harvard, Vancouver, ISO, etc.

14

Oh, Yoo Jin, Michael Hubauer-Brenner et Peter Hinterdorfer. « Influence of Surface Morphology on the Antimicrobial Effect of Transition Metal Oxides in Polymer Surface ». Journal of Nanoscience and Nanotechnology 15, n^o 10 (1 octobre 2015) : 7853–59. http://dx.doi.org/10.1166/jnn.2015.11215.

Texte intégral

Résumé :

In this study, the physical properties of transition metal oxide surfaces were examined using scanning probe microscopic (SPM) techniques for elucidating the antimicrobial activity of molybdenum trioxide (MoO3), tungsten trioxide (WO3), and zinc oxide (ZnO) embedded into the polymers thermoplastic polyurethane (TPU) and polypropylene (PP). We utilized atomic force microscopy (AFM) in the contact imaging mode and its derivative single-pass Kelvin probe force microscopy for investigating samples that were presumably identical in their compositions, but showed different antimicrobial activity in bacterial adhesion tests. Our results revealed that surfaces with larger roughness and higher surface potential variation showed stronger antimicrobial activities compared to smoother and homogeneously charge-distributed surfaces. In addition, capacitance gradient (dC/dZ) measurements were performed to elucidate the antimicrobial activity arising from the different dielectric behavior of the transition metal oxides in this heterogeneous polymer surface. We found that the nano-scale exposure of transition metal oxides on polymer surfaces provided strong antimicrobial effects. Applications arising from our studies will be useful for public and healthcare environments.

Styles APA, Harvard, Vancouver, ISO, etc.

15

Beyli, P. T., M. Doğan, Z. Gündüz, M. Alkan et Y. Turhan. « Synthesis, Characterization and Their Antimicrobial Activities of Boron Oxide/Poly(Acrylic Acid) Nanocomposites : Thermal and Antimicrobial Properties ». Advances in Materials Science 18, n^o 1 (1 mars 2018) : 28–36. http://dx.doi.org/10.1515/adms-2017-0025.

Texte intégral

Résumé :

AbstractBoron oxide (B2O3)/Poly(acrylic acid) (PAA) nanocomposites were synthesized by solution intercalation method, and characterized by Fourier transform infrared spectroscopy (FTIR-ATR), transmission electron microscopy (TEM), X-ray diffraction and thermogravimetric analysis (DTA/TG). The effect of boron oxide amount on the thermal stability of nanocomposites was investigated. Moreover, the antimicrobial activities of them were also determined by the serial dilution method against E. coli and S. aureus. XRD analysis showed that boron oxide was homogenously dispersed in polymer matrix; FTIR-ATR that there was interaction between PAA and boron oxide; and TEM that boron oxide particles had spherical structure, and dispersed in nano size in polymer matrix; DTA/TG that the thermal stability of polymers increased with the adding of boron oxide into polymer matrix, and changed the decomposition mechanism of PAA. B2O3/PAA nanocomposites exhibited higher decomposition temperature. The decomposition mechanisms of PAA and its nanocomposites occurred through three decomposition steps; dehydration, decarboxylation and chain scission. B2O3/PAA nanocomposites showed greater antimicrobial activity with increasing B2O3 amount.

Styles APA, Harvard, Vancouver, ISO, etc.

16

Ennis, BC, PJ Hanhela et DB Paul. « Organic Curing Agents for Polysulfide Sealants. III. A Mechanistic Interpretation of the Thermal Degradation of Nitrile Oxide-Cured Polysulfide Sealants ». Australian Journal of Chemistry 43, n^o 1 (1990) : 109. http://dx.doi.org/10.1071/ch9900109.

Texte intégral

Résumé :

Sealants obtained by cure of polysulfide liquid polymers with aryl bis ( nitrile oxides) possess the thiohydroximic acid ester structural feature. Unexpectedly these materials were found to exhibit poor thermal stability: when heated at 60° they soften within days and liquefy in 3 weeks. Products obtained with excess nitrile oxide degraded faster than those produced with equimolar amounts of reagents. Interpretations considered included (A) dissociation of the thiohydroximic acid group, (B) reaction between nitrile oxide and a reactive centre in the polysulfide structure, and (c) addition of nitrile oxide to the side chain. It was shown that neither of the first two possibilities was applicable. Moreover, spectroscopic studies demonstrated that, after an initial rapid addition between nitrile oxide and thiol , a second slower reaction occurred which consumed additional nitrile oxide. Although aldehyde oximes and a- chloro oximes do not participate in such processes unless catalysts are present, thiohydroximic acid derivatives were shown to react with nitrile oxides at ambient temperature to form 1,2,4-oxadiazole 4-oxides and alkyl thiol . For the case of a polysulfide sealant the equivalent rupture of a C-S bond to form the thiol involves cleavage of the polymer backbone. Continuation of the process would lead to degradation of the sealant. These observations were supported by thermal analysis studies on the polysulfide sealants and model polymers.

Styles APA, Harvard, Vancouver, ISO, etc.

17

Nawawi, Zainuddin, R. F. Kurnia, N. F. A. Isa, Z. Buntat, D. R. Yuniarti, M. I. Jambak et Muhammad Abu Bakar Sidik. « Electrical Potential Distribution in Polymethyl Methacrylate-Graphene Oxide Nanocomposites ». Indonesian Journal of Electrical Engineering and Computer Science 4, n^o 2 (1 novembre 2016) : 256. http://dx.doi.org/10.11591/ijeecs.v4.i2.pp256-262.

Texte intégral

Résumé :

<p>Research work of polymer nanocomposites in high voltage insulator becomes interest nowadays. Polymer based and nanofillers are the core components in polymer nanocomposites. By adding such a big amount of nanofiller it would enhance the electrical and mechanical properties of polymers. However as for today, a little percentage of nanofiller concentration could dramatically enhanced the properties of the polymeric material. Recent research of graphene oxide (GO) nanofiller has brought to this project interest. This paper presents several methods that have been published to development PMMA (poly methyl methacrylate)/GO nanocomposites and a simulation of PMMA/GO in order to investigate the potential distribution. </p>

Styles APA, Harvard, Vancouver, ISO, etc.

18

Alister G., Willis, et Saharudin Haron. « Synthesis of composite thin-film polymer consisting of tungsten and zinc oxide as hydrogen gas detector ». E3S Web of Conferences 90 (2019) : 01008. http://dx.doi.org/10.1051/e3sconf/20199001008.

Texte intégral

Résumé :

A composite polymer consisting of polyaniline (PANI) was synthesised via oxidative polymerisation by varying concentrations of transitional metal oxides and the presence of a hydrogen dissociation catalyst, palladium (Pd). The metal oxides chosen for this study were tungsten oxide (WO3) and zinc oxide (ZnO). The composite polymer samples were characterised using Fourier transform infrared (FTIR) spectroscopy where ultraviolet-visible (UV-Vis) spectroscopy was used to observe the optical changes of the thin films due to exposure to hydrogen. The FTIR spectra obtained confirmed the synthesis of PANI composite. Based on the UV-VIS analysis, PANI-ZnO composite polymer showed the highest difference in peak intensity before and after exposure to hydrogen with 11.4% difference.

Styles APA, Harvard, Vancouver, ISO, etc.

19

Moffatt, Dawne M., James P. Runt, Arvind Halliyal et Robert E. Newnham. « Metal oxide-polymer thermistors ». Journal of Materials Science 24, n^o 2 (février 1989) : 609–14. http://dx.doi.org/10.1007/bf01107449.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

20

Arthi Feiona, T., G. Sabeena, M. Sakthi Bagavathy, E. Pushpalaksmi, J. Jenson Samra et G. Annadurai. « Synthesis and Characterization of ZnO-MMT Nanocomposite for Antibacterial Activity Studies ». Journal of Applied Sciences and Environmental Management 24, n^o 6 (17 juillet 2020) : 1079–84. http://dx.doi.org/10.4314/jasem.v24i6.21.

Texte intégral

Résumé :

ZnO oxide Nanoparticle and ZnO oxide with Montmorillonite nanocomposite were prepared by an environmentally friendly, efficient, and inexpensive method that was synthesized using the chemical method. ZnO nanoparticles as an effective antibacterial material were immobilized on the surface of montmorillonite (MMT). The objectives of this paper are to summarize our research activities in (a) developing processes to dispersenanomaterials (undoped and doped zinc oxide powders) in the polymers matrix, (b) using X-ray diffraction (XRD), Fourier Transform Infra-Red Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM) and Thermo Gravimetric Analysis (TGA) techniques to characterize polymer matrix structures, (c) studying structure-property relationship of these types of new materials, and (d) evaluating the antibacterial performance of these materials for different applications. The results showed that the ZnO nanocomposite was uniformly dispersed in the polymer matrix and the particles remained their average size (20 - 150 nm) before incorporation into the polymer matrix. Keywords: Zinc Oxide nanoparticle, Montmorillonite, FTIR, Antibacterial activity

Styles APA, Harvard, Vancouver, ISO, etc.

21

Lee, Jung-Pil, Sinho Choi, Sungjin Cho, Woo-Jin Song et Soojin Park. « Fabrication of Carbon Nanofibers Decorated with Various Kinds of Metal Oxides for Battery Applications ». Energies 14, n^o 5 (2 mars 2021) : 1353. http://dx.doi.org/10.3390/en14051353.

Texte intégral

Résumé :

Carbon nanofibers decorated with various metal oxide nanoparticles were fabricated by combining an electrospinning technique of bicomponent polymer mixture and a sol-gel reaction and subsequent carbonization process. Electrospun polymer nanofibers consisting of polyacrylonitrile (PAN) and poly(vinyl pyrrolidone) (PVP) with controllable diameters were fabricated with PAN/PVP core/shell types via phase-separation due to the immiscibility between two polymers. The electrospun nanofibers served as supporting materials with binding sites of PVP to incorporate titanium oxide precursor. Subsequently, the carbonization of the fibers led to the formation of carbon nanofibers@TiO2 for energy application, in which rutile TiO2 nanoparticles were decorated on the surface of carbon nanofiber. Especially, this TiO2 decorated carbon nanofiber electrode exhibited excellent electrochemical property in lithium-ion batteries (≈600 mA h g−1 at C/5 rate for 100 cycles). Furthermore, the carbon nanofibers were also successfully modified with other metal oxides, including NiO, SnO2, and ZrO2 nanoparticles, in a similar manner.

Styles APA, Harvard, Vancouver, ISO, etc.

22

Mitchell, G. R., M. Belal, F. J. Davis, D. E. Elliott, M. Kariduraganavar, S. D. Mohan, R. H. Olley et Sujat Sen. « Defining Structure in Electrospun Polymer Fibres ». Advanced Materials Research 55-57 (août 2008) : 33–36. http://dx.doi.org/10.4028/www.scientific.net/amr.55-57.33.

Texte intégral

Résumé :

We use a combination of microscopy, x-ray scattering and neutron scattering to show how structure develops in micro and nano-size polymer fibres prepared by electrospinning. The technique has been applied to a range of different polymers, an amorphous system (polystyrene), a crystallisable polymer (poly-ε-caprolactone), a composite systems (polyethylene oxide or poly vinyl alcohol containing polypyrrole) and consider the possibility of self assembly (gelatin).

Styles APA, Harvard, Vancouver, ISO, etc.

23

Qiao, Jun, Yiyan Chen et Gregory L. Baker. « Polymer Electrolytes Based on Unsaturated Ethylene Oxide-Segmented Polymers ». Chemistry of Materials 11, n^o 9 (septembre 1999) : 2542–47. http://dx.doi.org/10.1021/cm990250i.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

24

Shcherbakov, Alexander B., Vladimir V. Reukov, Alexander V. Yakimansky, Elena L. Krasnopeeva, Olga S. Ivanova, Anton L. Popov et Vladimir K. Ivanov. « CeO2 Nanoparticle-Containing Polymers for Biomedical Applications : A Review ». Polymers 13, n^o 6 (17 mars 2021) : 924. http://dx.doi.org/10.3390/polym13060924.

Texte intégral

Résumé :

The development of advanced composite biomaterials combining the versatility and biodegradability of polymers and the unique characteristics of metal oxide nanoparticles unveils new horizons in emerging biomedical applications, including tissue regeneration, drug delivery and gene therapy, theranostics and medical imaging. Nanocrystalline cerium(IV) oxide, or nanoceria, stands out from a crowd of other metal oxides as being a truly unique material, showing great potential in biomedicine due to its low systemic toxicity and numerous beneficial effects on living systems. The combination of nanoceria with new generations of biomedical polymers, such as PolyHEMA (poly(2-hydroxyethyl methacrylate)-based hydrogels, electrospun nanofibrous polycaprolactone or natural-based chitosan or cellulose, helps to expand the prospective area of applications by facilitating their bioavailability and averting potential negative effects. This review describes recent advances in biomedical polymeric material practices, highlights up-to-the-minute cerium oxide nanoparticle applications, as well as polymer-nanoceria composites, and aims to address the question: how can nanoceria enhance the biomedical potential of modern polymeric materials?

Styles APA, Harvard, Vancouver, ISO, etc.

25

Rubin Pedrazzo, Alberto, Claudio Cecone, Sara Morandi, Maela Manzoli, Pierangiola Bracco et Marco Zanetti. « Nanosized SnO2 Prepared by Electrospinning : Influence of the Polymer on Both Morphology and Microstructure ». Polymers 13, n^o 6 (23 mars 2021) : 977. http://dx.doi.org/10.3390/polym13060977.

Texte intégral

Résumé :

An electrospinning (ES) procedure of polymeric solutions containing metal oxide precursors, followed by thermal treatments, was exploited to obtain SnO2 nanofibers. Attention was focused on the effect of different templating polymers (polyvinyl pyrrolidone (PVP), polyethylene oxide (PEO) and polyvinyl acetate (PVAc)) on the morphologies and particle size distributions of SnO2. We demonstrated that with different polymers, the final oxide’s morphology and crystallite size change. Defined fibers, with homogeneous diameter, were obtained with each polymer, but, after calcination, the morphology of the oxide changes, leading to fibers, “flakes” or “sphere-shaped” particles when PVP, PEO or PVAc were used, respectively, as evidenced by SEM images. Data from HR-TEM and XRD measurements confirm that SnO2 samples consist of crystalline cassiterite, with small mean particle dimensions calculated by Debye–Scherrer equation, i.e., 30, 11 and 25 nm with PVP, PEO and PVAc, respectively. TEM measurements put in evidence lower average particle sizes and for SnO2 obtained with PEO average size of 8.5 nm with a standard deviation of ±4.9 nm was evidenced. By applying different calcination temperatures on fiber mat obtained by the same polymer, i.e., PEO, the influence of polymer not only on the final shape of the oxide particles but also on the crystallite size was definitively demonstrated.

Styles APA, Harvard, Vancouver, ISO, etc.

26

Singh, Sudhanshu, Deepshikha Rathore et Umesh Kumar Dwivedi. « Metal Oxide Hybrids and their Polymer Nanocomposites with its Various Properties ». Journal of Advanced Research in Dynamical and Control Systems 11, n^o 10-SPECIAL ISSUE (31 octobre 2019) : 964–70. http://dx.doi.org/10.5373/jardcs/v11sp10/20192893.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

27

Morita, Mayu, Yutaka Oya, Nobuhiko Kato, Kazuki Mori et Jun Koyanagi. « Effect of Electrostatic Interactions on the Interfacial Energy between Thermoplastic Polymers and Graphene Oxide : A Molecular Dynamics Study ». Polymers 14, n^o 13 (25 juin 2022) : 2579. http://dx.doi.org/10.3390/polym14132579.

Texte intégral

Résumé :

In this study, the atomistic-scale mechanisms affecting the interfacial stability of a thermoplastic polymer/graphene oxide interface are investigated using molecular dynamics simulations. Different combinations of thermoplastic polymers (polyethersulfone (PES) and polyetherimide (PEI)) and graphene oxides modified with –O–, –OH, and –COOH are prepared. PES is found to be more strongly stabilized with modified/functionalized graphene oxide in the order of –COOH, –OH, –O–, which is opposite to the stability order of PEI. Our results suggest that these orders of stability are governed by a balance between the following two factors resulting from electrostatic interactions: (1) atoms with a strong charge bias attract each other, thereby stabilizing the interface; (2) the excluded-volume effect of the functional groups on graphene oxide destabilizes the interface by preventing π-π stacking of aromatic rings.

Styles APA, Harvard, Vancouver, ISO, etc.

28

Grebel, Haim, Liliana Stan, Anirudha Sumant, Yuzi Liu, David Gosztola, Leonidas Ocola et Brandon Fisher. « Transfer of Graphene with Protective Oxide Layers ». ChemEngineering 2, n^o 4 (3 décembre 2018) : 58. http://dx.doi.org/10.3390/chemengineering2040058.

Texte intégral

Résumé :

Transfer of graphene, grown by chemical vapor deposition (CVD), to a substrate of choice, typically involves the deposition of a polymeric layer (for example, poly(methyl methacrylate) (PMMA), or polydimethylsiloxane, PDMS). These polymers are quite hard to remove without leaving some residues behind. One method to improve the graphene transfer is to coat the graphene with a thin protective oxide layer, followed by the deposition of a very thin polymer layer on top of the oxide layer (much thinner than the usual thickness), followed by a more aggressive polymeric removal method, thus leaving the graphene intact. At the same time, having an oxide layer on graphene may serve applications, such as channeled transistors or sensing devices. Here, we study the transfer of graphene with a protective thin oxide layer grown by atomic layer deposition (ALD). We follow the transfer process from the graphene growth stage through oxide deposition until completion. We report on the nucleation growth process of oxides on graphene, their resultant strain and their optical transmission.

Styles APA, Harvard, Vancouver, ISO, etc.

29

Khan, Dost Muhammad, Ayesha Kausar et Syed M. Salman. « Exploitation of Nanobifiller in Polymer/Graphene Oxide–Carbon Nanotube, Polymer/Graphene Oxide–Nanodiamond, and Polymer/Graphene Oxide–Montmorillonite Composite : A Review ». Polymer-Plastics Technology and Engineering 55, n^o 7 (5 novembre 2015) : 744–68. http://dx.doi.org/10.1080/03602559.2015.1103266.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

30

Khramenkova, A. V., D. N. Ariskina et K. R. Yuzhakova. « Production of Hybrid Polymer-Oxide Materials Based on Molybdenum Oxide Compounds Using Transient Electrolysis Method ». Solid State Phenomena 299 (janvier 2020) : 316–20. http://dx.doi.org/10.4028/www.scientific.net/ssp.299.316.

Texte intégral

Résumé :

Сatalytically active hybrid polymer-oxide material, based on molybdenum oxide compounds with iron group (Fe, Ni, Co) metals and polyvinyl-pyrrolidone, is obtained by method of transient electrolysis. Surface morphology and elemental composition of the obtained hybrid polymer-oxide material are examined with an electron microscopy and X-ray micro-fluorescent microanalysis; its phase composition and its chemical bonds structure formation between metal oxide compounds and polymer macromolecules are determined by X-ray phase analysis and IR spectroscopy. High catalytic activity of the obtained hybrid polymer-oxide material in the model reaction of hydrogen peroxide decomposition by the gaso-metric method is shown, which allows us to conclude that it is possible to use the obtained hybrid polymer-oxide materials as catalysts for wastewater treatment to purify it from organic and inorganic impurities.

Styles APA, Harvard, Vancouver, ISO, etc.

31

Kancharla, Samhitha, Nathan A. Zoyhofski, Lucas Bufalini, Boris F. Chatelais et Paschalis Alexandridis. « Association between Nonionic Amphiphilic Polymer and Ionic Surfactant in Aqueous Solutions : Effect of Polymer Hydrophobicity and Micellization ». Polymers 12, n^o 8 (15 août 2020) : 1831. http://dx.doi.org/10.3390/polym12081831.

Texte intégral

Résumé :

The interaction in aqueous solutions of surfactants with amphiphilic polymers can be more complex than the surfactant interactions with homopolymers. Interactions between the common ionic surfactant sodium dodecyl sulfate (SDS) and nonionic amphiphilic polymers of the poly(ethylene oxide)–poly(propylene oxide)–poly(ethylene oxide) (PEO-PPO-PEO) type have been probed utilizing a variety of experimental techniques. The polymer amphiphiles studied here are Pluronic F127 (EO100PO65EO100) and Pluronic P123 (EO19PO69EO19), having the same length PPO block but different length PEO blocks and, accordingly, very different critical micellization concentrations (CMC). With increasing surfactant concentration in aqueous solutions of fixed polymer content, SDS interacts with unassociated PEO-PPO-PEO molecules to first form SDS-rich SDS/Pluronic assemblies and then free SDS micelles. SDS interacts with micellized PEO-PPO-PEO to form Pluronic-rich SDS/Pluronic assemblies, which upon further increase in surfactant concentration, break down and transition into SDS-rich SDS/Pluronic assemblies, followed by free SDS micelle formation. The SDS-rich SDS/Pluronic assemblies exhibit polyelectrolyte characteristics. The interactions and mode of association between nonionic macromolecular amphiphiles and short-chain ionic amphiphiles are affected by the polymer hydrophobicity and its concentration in the aqueous solution. For example, SDS binds to Pluronic F127 micelles at much lower concentrations (~0.01 mM) when compared to Pluronic P123 micelles (~1 mM). The critical association concentration (CAC) values of SDS in aqueous PEO-PPO-PEO solutions are much lower than CAC in aqueous PEO homopolymer solutions.

Styles APA, Harvard, Vancouver, ISO, etc.

32

Gervais, Matthieu, Anne-Laure Brocas, Alain Deffieux, Emmanuel Ibarboure et Stephane Carlotti. « Rapid and controlled synthesis of hydrophobic polyethers by monomer activation ». Pure and Applied Chemistry 84, n^o 10 (24 juin 2012) : 2103–11. http://dx.doi.org/10.1351/pac-con-11-11-16.

Texte intégral

Résumé :

A series of polyethers was prepared by monomer-activated anionic polymerization. The combination of an ammonium salt with triisobutylaluminum allowed the polymerization of epoxides containing various aliphatic side chains (1,2-butene oxide (BO), 1,2-hexene oxide (HO), and 1,2-octadecene oxide (ODO)) or a fluorinated group (3,3,3-trifluoro-1,2-epoxypropane (TFEP)). Polymers of molar masses up to 35 000 g/mol with relatively narrow molar mass distribution could be synthesized. Polymer structures were analyzed by 13C NMR, and the thermal behavior was studied by differential scanning calorimetry (DSC). The evolution of hydrophobicity was investigated according to the length and composition of the side chain. Using a long aliphatic side-chain epoxide (C16) imparted crystallinity to the resulting atactic polymer.

Styles APA, Harvard, Vancouver, ISO, etc.

33

Quirk, Roderic P., et Deanna L. Gomochak. « Recent Advances in Anionic Synthesis of Chain-End Functionalized Elastomers Using Epoxides and Related Compounds ». Rubber Chemistry and Technology 76, n^o 4 (1 septembre 2003) : 812–31. http://dx.doi.org/10.5254/1.3547774.

Texte intégral

Résumé :

Abstract Recent developments are reviewed for the applications of reactions of polymeric organolithium compounds with epoxides and oxetane to obtain the corresponding ω-hydroxy chain-end functionalized polymers. State-of-the-art characterization methods for ω-functionalized polymers are also reviewed. Investigations of the usefulness of functionalization reactions of polymeric organolithium compounds with ethylene oxide, propylene oxide, 1-butene oxide, styrene oxide, oxetane, 3,4-epoxy-1-butene, 3-glycidoxypropyltrimethoxysilane and other epoxides are described. In general, these functionalization reactions are very efficient (> 90% yields of ω-hydroxy-functionalized polymers). The use of substituted epoxides is shown to provide an efficient methodology for attachment of a variety of groups at the polymer chain end.

Styles APA, Harvard, Vancouver, ISO, etc.

34

Vergnat, Virginie, Benoît Heinrich, Michel Rawiso, René Muller, Geneviève Pourroy et Patrick Masson. « Iron Oxide/Polymer Core–Shell Nanomaterials with Star-like Behavior ». Nanomaterials 11, n^o 9 (21 septembre 2021) : 2453. http://dx.doi.org/10.3390/nano11092453.

Texte intégral

Résumé :

Embedding nanoparticles (NPs) with organic shells is a way to control their aggregation behavior. Using polymers allows reaching relatively high shell thicknesses but suffers from the difficulty of obtaining regular hybrid objects at gram scale. Here, we describe a three-step synthesis in which multi-gram NP batches are first obtained by thermal decomposition, prior to their covalent grafting by an atom transfer radical polymerization (ATRP) initiator and to the controlled growing of the polymer shell. Specifically, non-aggregated iron oxide NPs with a core principally composed of γ-Fe2O3 (maghemite) and either polystyrene (PS) or polymethyl methacrylate (PMMA) shell were elaborated. The oxide cores of about 13 nm diameter were characterized by dynamic light scattering (DLS), transmission electron microscopy (TEM), and small-angle X-ray scattering (SAXS). After the polymerization, the overall diameter reached 60 nm, as shown by small-angle neutron scattering (SANS). The behavior in solution as well as rheological properties in the molten state of the polymeric shell resemble those of star polymers. Strategies to further improve the screening of NP cores with the polymer shells are discussed.

Styles APA, Harvard, Vancouver, ISO, etc.

35

DiPaola-Baranyi, Giuseppa, Jocelyn Richer et William M. Prest Jr. « Thermodynamic miscibility of polystyrene–poly(2,6-dimethyl-1,4-phenylene oxide) blends ». Canadian Journal of Chemistry 63, n^o 1 (1 janvier 1985) : 223–27. http://dx.doi.org/10.1139/v85-036.

Texte intégral

Résumé :

Inverse gas chromatography was used to investigate the miscibility behaviour of molten polystyrene–poly(2,6-dimethyl-1,4-phenylene oxide) blends as a function of composition (0, 25, 50, 75, 85, and 100 wt.% PS). Specific retention volumes were measured for various solutes in pure and mixed stationary phases of these polymers at 240 °C. Infinite dilution weight fraction activity coefficients and Flory–Huggins polymer–solute (χ) and polymer–polymer (χ23′) interaction parameters were derived from these data.Negative polymer–polymer interaction parameters were obtained for blends containing more than 60 wt.% PS, suggesting strong intermolecular interactions in the molten state. This is in accord with the well-known compatibility of PS–PPO blends. However, positive χ23′ values were observed for blends containing less than 60 wt.% PS. This suggests weak intermolecular interactions, and perhaps some microheterogeneity in PS–PPO blends with a low PS content. In view of the single, composition dependent Tg measured for each of these blends the microheterogeneity or microphase separation must be on a finer scale than that measured by the glass transition.

Styles APA, Harvard, Vancouver, ISO, etc.

36

Vartanyan, Maria, Ilya Voytovich, Irina Gorbunova et Nikolay Makarov. « Preparation and Structural Characterization of Complex Oxide Eutectic Precursors from Polymer–Salt Xerogels Obtained by Microwave-Assisted Drying ». Materials 13, n^o 8 (11 avril 2020) : 1808. http://dx.doi.org/10.3390/ma13081808.

Texte intégral

Résumé :

Sol–gel synthesis is an acknowledged method for obtaining fine inorganic powders of a different nature. Implementation of water-soluble polymers as gel-forming media makes this technique even more readily available, especially in cases where conventional gel formation is suppressed. In polymer–salt solutions, polymers serve as scaffolds for salt constituents’ bulk crystallization. When dried, solid salt particles are deposited on the polymer surface or in polymer matrix pores, which leads to higher grain size uniformity. The present work discusses the effect of drying conditions on phase composition and structure characteristics of complex oxide eutectics in ternary systems, CaO–Al2O3–Y2O3 (CAY) and MgO–Al2O3–Y2O3 (MAY), obtained from polymer–salt compositions based on polyvinyl alcohol (PVA), Na-salt of carboxymethylcellulose (Na-CMC) or polyvinylpyrrolidone (PVP). Microwave-assisted drying proved to be more efficient compared to convective process; however such technique requires careful selection of gel-forming polymer.

Styles APA, Harvard, Vancouver, ISO, etc.

37

Mutlu, Mustafa Umut, Osman Akin, Mustafa M. Demir et Ümit Hakan Yildiz. « Fabrication of Polymer Nanofiber-Conducting Polymer Fabric and Noncontact Motion Sensing Platform ». Materials Science Forum 915 (mars 2018) : 207–12. http://dx.doi.org/10.4028/www.scientific.net/msf.915.207.

Texte intégral

Résumé :

Conductive polymer-electrospun polymer nanofiber network was combined to host iron oxide nanoparticles providing micrometer thick sensing interface. The sensor has fabricated as free-standing fabric exhibiting 10 to 100 KOhm base resistivity upon bias applied. The moving object has been sensed through the electrostatic interactions between fibers and object. The sensing range has been found to be 1-5 cm above the surface of fabric. By the controlled combination of conductive polymers electrospun polymer nanofibers effective device miniaturization has been provided without loss of performance. The noncontact motion sensor platform has unique flexibility and light weight holding a potential for wearable sensor technology.

Styles APA, Harvard, Vancouver, ISO, etc.

38

Varghese, Siby, Yosuke Katsumura, Keizo Makuuchi et Fumio Yoshi. « Effect of Water Soluble Polymers on Radiation Vulcanized Natural Rubber Latex Films ». Rubber Chemistry and Technology 72, n^o 2 (1 mai 1999) : 308–17. http://dx.doi.org/10.5254/1.3538803.

Texte intégral

Résumé :

Abstract Technological properties of radiation vulcanized latex after mixing with water soluble polymers (WSP) such as poly(vinyl alcohol), poly(ethylene oxide) etc. have been studied in detail. The properties of water soluble polymer incorporated vulcanizates depend mainly on the type of the polymer blended into the latex. Most of the polymers showed a drastic increase in tear strength with polymer content and a reduction in tackiness of the vulcanized films. Radiation processing increases the water soluble protein content in the serum phase whereas that in the rubber phase decreases. Addition of water soluble polymer causes the fast leaching of soluble proteins from the dried films, which reduces the prolonged leaching commonly adopted for rubber vulcanizates. Aging properties of radiation vulcanized films incorporated with water soluble polymers are excellent. The thermal degradation behavior of radiation vulcanized films and that of water soluble polymer incorporated films is almost the same. Transparency of the rubber films can be increased by the addition of suitable water soluble polymers.

Styles APA, Harvard, Vancouver, ISO, etc.

39

Galusek, D., Z. Lencés, P. Sajgalík et Ralf Riedel. « Thermal analysis study of polymer-to-ceramic conversion of organosilicon precursors ». Journal of Mining and Metallurgy, Section B : Metallurgy 44, n^o 1 (2008) : 35–38. http://dx.doi.org/10.2298/jmmb0801035g.

Texte intégral

Résumé :

The organosilicon precursors attract significant attention as substances, which upon heating in inert or reactive atmosphere convert directly to oxide or non-oxide ceramics, like nitrides, carbides, carbonitrides, boroncarbonitrides, oxycarbides, alons, etc. In characterisation, and in study of conversion of these polymers to ceramics thermal analysis plays an important role. The degree of cross-linking of the polymer vital for achievement of high ceramic yield is estimated with the use of thermal mechanical analysis (TMA). Decomposition of polymers and their conversion to ceramics is studied by the combination of differential thermal analysis (DTA), differential scanning calorimetry (DSC) thermogravimetry(TG), and mass spectrometry (MS). The use of these methods in study of the polymer-to-ceramic conversion is illustrated by case studies of a commercially available poly(allyl)carbosilane as the precursor of SiC, and a poly(hydridomethyl)silazane as the precursor of SiCN.

Styles APA, Harvard, Vancouver, ISO, etc.

40

Capelezzo, Ana Paula, Laura Cassol Mohr, Janayne Sander Godoy, Alessandra Sgnaulin Bellei, Luciano Luiz Silva, Maria Ana Pignatel Marcon Martins, Márcio Antônio Fiori et Josiane Maria Muneron Mello. « Addition of Zinc Oxide Nanoparticles in Biodegradable Polymer and Evaluation of its Antimicrobial Activity ». Materials Science Forum 930 (septembre 2018) : 230–35. http://dx.doi.org/10.4028/www.scientific.net/msf.930.230.

Texte intégral

Résumé :

The food contamination for pathogenic microorganisms is a serious problem for the food security. Many actions can be taken in order to reduce this pathogenic multiplication, highlighting the use of active packaging for the food conservation, which have antimicrobial agents dispersed in its surface. The metal oxides and its nanoparticles have been shown effective additives for this purpose. With the growing concern with the environmental and the use of less aggressive materials, biodegradable polymers emerge like a good alternative. This work has the goal to investigate the effect on antimicrobial activity against Gram negative (Escherichia coli) and Gram positive (Staphylococcus aureus) bacteria when added zinc oxide nanoparticles (ZnO NPs) in concentration of 1% (wt/wt) in the biodegrable polymer Ecoflex®. The system was homogenized and proccessed in industrial extruder single screw and the polymer’s antimicrobial activity was evaluated by the agar diffusion tests and counting surviving microorganisms with the time. The results showed that the biodegradable polymer Ecoflex®with ZnO NPs exhibit good antibacterial activity.

Styles APA, Harvard, Vancouver, ISO, etc.

41

Adamenko, N. A., G. V. Agafonova, D. V. Savin, A. I. Bogdanov, D. A. An et A. V. Kazurov. « RESEARCH OF THE CRYSTALLINE STRUCTURE OF POLYMERIC COMPOSITE MIXTURES AFTER EXPLOSIVE PRESSING ». IZVESTIA VOLGOGRAD STATE TECHNICAL UNIVERSITY, n^o 4(239) (22 avril 2020) : 23–27. http://dx.doi.org/10.35211/1990-5297-2020-4-239-23-27.

Texte intégral

Résumé :

The method of X-ray diffraction analysis was used to study polymer composites based on thermoplastic polymers of ultra-high molecular weight polyethylene UHMWPE with β-sialon and polytetrafluoroethylene PTFE with aluminum oxide Al2O3 after static and explosive pressing. The studies were carried out with the aim of developing explosive pressing technology for polymer composite materials with enhanced strength and antifriction properties.

Styles APA, Harvard, Vancouver, ISO, etc.

42

Zhang, Xiao Zhou, Xi Gao Jian et Li Wu Zu. « Efficient Photovoltaic Devices Using Zinc Oxide Nanowires Overlaid with Conjugated Polymers ». Applied Mechanics and Materials 151 (janvier 2012) : 231–34. http://dx.doi.org/10.4028/www.scientific.net/amm.151.231.

Texte intégral

Résumé :

Bulk heterojunction photovolataic devices based on blends of conjugated polymer poly (2- methoxyl-5- dodecoxyl p-phenyl vinylene) (PMODOPV) as electron donor and crystalline ZnO nanowires as electron acceptor have been studied. We show that photovoltaic devices using zinc oxide nanowires overlaid with conjugated polymers give improved performance compared with devices made only from polymer. The improvement is consistent with improved electron transport perpendicular to the plane of the film. Solar power conversion efficiency of 1.37% were achieved under AM1.5 illumination .

Styles APA, Harvard, Vancouver, ISO, etc.

43

Gobi, Ravichandran, Palanisamy Ravichandiran, Ravi Shanker Babu et Dong Jin Yoo. « Biopolymer and Synthetic Polymer-Based Nanocomposites in Wound Dressing Applications : A Review ». Polymers 13, n^o 12 (13 juin 2021) : 1962. http://dx.doi.org/10.3390/polym13121962.

Texte intégral

Résumé :

Biopolymers are materials obtained from a natural origin, such as plants, animals, microorganisms, or other living beings; they are flexible, elastic, or fibrous materials. Polysaccharides and proteins are some of the natural polymers that are widely used in wound dressing applications. In this review paper, we will provide an overview of biopolymers and synthetic polymer-based nanocomposites, which have promising applications in the biomedical research field, such as wound dressings, wound healing, tissue engineering, drug delivery, and medical implants. Since these polymers have intrinsic biocompatibility, low immunogenicity, non-toxicity, and biodegradable properties, they can be used for various clinical applications. The significant advancements in materials research, drug development, nanotechnology, and biotechnology have laid the foundation for changing the biopolymeric structural and functional properties. The properties of biopolymer and synthetic polymers were modified by blending them with nanoparticles, so that these materials can be used as a wound dressing application. Recent wound care issues, such as tissue repairs, scarless healing, and lost tissue integrity, can be treated with blended polymers. Currently, researchers are focusing on metal/metal oxide nanomaterials such as zinc oxide (ZnO), cerium oxide (CeO2), silver (Ag), titanium oxide (TiO2), iron oxide (Fe2O3), and other materials (graphene and carbon nanotubes (CNT)). These materials have good antimicrobial properties, as well as action as antibacterial agents. Due to the highly antimicrobial properties of the metal/metal oxide materials, they can be used for wound dressing applications.

Styles APA, Harvard, Vancouver, ISO, etc.

44

Díez-Pascual, Ana M., et José A. Luceño-Sánchez. « Antibacterial Activity of Polymer Nanocomposites Incorporating Graphene and Its Derivatives : A State of Art ». Polymers 13, n^o 13 (26 juin 2021) : 2105. http://dx.doi.org/10.3390/polym13132105.

Texte intégral

Résumé :

The incorporation of carbon-based nanostructures into polymer matrices is a relevant strategy for producing novel antimicrobial materials. By using nanofillers of different shapes and sizes, and polymers with different characteristics, novel antimicrobial nanocomposites with synergistic properties can be obtained. This article describes the state of art in the field of antimicrobial polymeric nanocomposites reinforced with graphene and its derivatives such as graphene oxide and reduced graphene oxide. Taking into account the vast number of articles published, only some representative examples are provided. A classification of the different nanocomposites is carried out, dividing them into acrylic and methacrylic matrices, biodegradable synthetic polymers and natural polymers. The mechanisms of antimicrobial activity of graphene and its derivatives are also reviewed. Finally, some applications of these antimicrobial nanocomposites are discussed. We aim to enhance understanding in the field and promote further work on the development of polymer-based antimicrobial nanocomposites incorporating graphene-based nanomaterials.

Styles APA, Harvard, Vancouver, ISO, etc.

45

Bahramnia, Hamed, Hamidreza Mohammadian Semnani, Ali Habibolahzadeh et Hassan Abdoos. « Epoxy/polyurethane nanocomposite coatings for anti-erosion/wear applications : A review ». Journal of Composite Materials 54, n^o 22 (12 mars 2020) : 3189–203. http://dx.doi.org/10.1177/0021998320908299.

Texte intégral

Résumé :

Offshore pipelines are vulnerable against erosion/wear deterioration mechanisms that can be controlled through the use of proper surface coatings, such as polymer matrix nano-composite (PMNC) coatings that are well-known for their ease of production, availability and applicability. Epoxy, as a versatile rigid and brittle resin and polyurethane with proper chemical/mechanical properties, are potential candidates to make the matrix of these composites. A combination of these polymers can also enhance the mechanical behaviors, glass transition temperature and flexibility. In addition, the desired coating characteristics, such as adhesion to metal substrate, mechanical properties, erosion/wear resistivity and UV absorbance, can be further improved through the addition of appropriate nanoparticles within the polymer matrix. Especially, nanoparticles can improve the erosion/wear resistance of polymers because of establishing high strength bonds between the polymer chains and the reinforcements besides enhancing other required properties. The present work is a review on PMNC coatings that contain epoxy, polyurethane or EP/polyurethane as a polymer matrix along with the details of the nanoparticle reinforcements, such as alumina, silica, titanium oxide, zinc oxide, clay and carbon-based materials. The effect of these nanoparticles on the properties of composite coatings has also been investigated.

Styles APA, Harvard, Vancouver, ISO, etc.

46

Wood, Nathan D., Lisa J. Gillie, David J. Cooke et Marco Molinari. « A Review of Key Properties of Thermoelectric Composites of Polymers and Inorganic Materials ». Materials 15, n^o 23 (5 décembre 2022) : 8672. http://dx.doi.org/10.3390/ma15238672.

Texte intégral

Résumé :

This review focusses on the development of thermoelectric composites made of oxide or conventional inorganic materials, and polymers, with specific emphasis on those containing oxides. Discussion of the current state-of-the-art thermoelectric materials, including the individual constituent materials, i.e., conventional materials, oxides and polymers, is firstly presented to provide the reader with a comparison of the top-performing thermoelectric materials. Then, individual materials used in the inorganic/polymer composites are discussed to provide a comparison of the performance of the composites themselves. Finally, the addition of carbon-based compounds is discussed as a route to improving the thermoelectric performance. For each topic discussed, key thermoelectric properties are tabulated and comparative figures are presented for a wide array of materials.

Styles APA, Harvard, Vancouver, ISO, etc.

47

Zhang, Xiaoxian, Jing Tian et Chunmei Jia. « Advances in the Study of Gel Polymer Electrolytes in Electrochromic Devices ». Journal of Progress in Engineering and Physical Science 2, n^o 1 (mars 2023) : 47–53. http://dx.doi.org/10.56397/jpeps.2023.03.06.

Texte intégral

Résumé :

The electrolytes in electrochromic devices (ECDs) serve as a conduction medium between electrodes and providing compensating ions for electrochromic reactions. Their characteristics directly affect the performance of electrochromic devices. Due to their ease of processing and encapsulation and high ionic conductivity, polymer gel electrolytes are widely used in electrochromic devices. As gel electrolyte polymers, polyethylene oxide (PEO), polymethyl methacrylate (PMMA), and polyvinylidene fluoride (PVDF) are reviewed according to their polymer matrix. Furthermore, future development trends in gel polymer electrolytes are discussed.

Styles APA, Harvard, Vancouver, ISO, etc.

48

Faeq Kareem, Fairooz, Asrar Abd. Saeed, Mahasin F. Hadi et Farah Jawad Kadhum. « Absorption Characteristics of Magnesium Oxide and Aluminium Oxide NPs/ Rhodamine 6G/ Polyvinyl Alcohol Films ». Journal of Kufa-Physics 13, n^o 02 (10 décembre 2021) : 51–57. http://dx.doi.org/10.31257/2018/jkp/2021/130207.

Texte intégral

Résumé :

Pure Polyvinyl Alcohol (PVA) film and PVA polymer film/ Rhodamine 6G(Rh6G) dye film in different volume ratios of (6, 12,18, 24 and 30) ml of Rh6G were prepared via casting method. The addition of Magnesium Oxide (MgO) and Aluminium Oxide (Al2O3) nanoparticles as a filler to the polymer matrix. The results demonstrated that there was a 10 nm red shift in the absorption spectra of Rh6G in PVA/ Rh6G polymer matrix due to add doping ratio of Rh6G dye solution to the transparent PVA matrix. Also, there was a 5 nm red shift in polymer matrix filled with Al2O3 NPs; this means that Al2O3 NPs absorb the water and that consequently enhance the optical properties of polymer matrix. The intensity of Rh6G doped PVA polymer film was seen to be enhanced when adding MgO NPs or Al2O3 NPs, noted that intensity of adding Al2O3 NPs more than it when adding MgO NP. The electronic transition was found to be π→π*.

Styles APA, Harvard, Vancouver, ISO, etc.

49

Ioni, Yu V., Yu A. Groshkova, S. P. Gubin et E. Yu Buslaeva. « Graphene Oxide as a Polymer ». Nanotechnologies in Russia 15, n^o 2 (mars 2020) : 163–68. http://dx.doi.org/10.1134/s1995078020020111.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

50

Herrmann, Wolfgang A., Roland M. Kratzer, Janet Blümel, Holger B. Friedrich, Richard W. Fischer, David C. Apperley, Janos Mink et Otto Berkesi. « Polymer-bound osmium oxide catalysts ». Journal of Molecular Catalysis A : Chemical 120, n^o 1-3 (juin 1997) : 197–205. http://dx.doi.org/10.1016/s1381-1169(96)00419-0.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Articles de revues sur le sujet « POLYMER OXIDE »

Créez une référence correcte selon les styles APA, MLA, Chicago, Harvard et plusieurs autres