Articles de revues : « Optical Properties - Nanocomposites »

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Sangawar, Vijaya S., et Manisha C. Golchha. « Optical Properties of ZnO/Low Density Polyethylene Nanocomposites ». International Journal of Scientific Research 2, n^o 7 (1 juin 2012) : 490–92. http://dx.doi.org/10.15373/22778179/july2013/169.

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Ramazanov, MA, FV Hajiyeva, YA Babayev, GV Valadova, SG Nuriyeva et HA Shirinova. « Synthesis and optical properties of PVC-CdS-based nanocomposites ». Journal of Elastomers & ; Plastics 52, n^o 2 (14 février 2019) : 159–66. http://dx.doi.org/10.1177/0095244319827989.

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Poly(vinyl chloride) (PVC)–cadmium sulfide (CdS) nanocomposite films were successfully synthesized by ex situ solution casting method. Scanning electron microscopy showed that CdS nanoparticles are well monodispersed in the PVC matrix. From the ultraviolet (UV) spectra of nanocomposites, the width of the forbidden band for polymer nanocomposites was determined by extrapolation method. UV-visible optical spectra revealed that the optical band of nanocomposites is increased with increasing concentration of CdS nanoparticles in the PVC matrix. It was found that the band gap is 3.8 eV for PVC-3% CdS nanocomposites, 2.7 eV for PVC-5% CdS, and 2.35 eV for PVC-10% CdS nanocomposites. Photoluminescence spectrum of PVC-CdS-based nanocomposites shows two luminescent peaks at the wavelengths of 436 nm and 472 nm at the luminescence spectrum which belongs to CdS nanoparticles. Photoluminescence study shows that PVC-CdS nanocomposites exhibit a great blue shift (approximately 100 nm) compared with bulk CdS nanoparticles.

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Musbah, Salah, Vesna Radojevic, Nadezda Borna, Dusica Stojanovic, Miroslav Dramicanin, Aleksandar Marinkovic et Radoslav Aleksic. « PMMA-Y2O3 (Eu3+) nanocomposites : Optical and mechanical properties ». Journal of the Serbian Chemical Society 76, n^o 8 (2011) : 1153–61. http://dx.doi.org/10.2298/jsc100330094m.

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The results of a study related to the processing and characterization of PMMA-Y2O3 (Eu3+) nanocomposites are presented herein. The nanocomposite samples were prepared using a laboratory mixing molder with different contents of Eu-ion doped Y2O3 nanophosphor powder. The influence of particle content on the optical and dynamic mechanical properties of the nanocomposites was investigated. The intensity of the luminescence emission spectra increased as the nanophosphor content in the composite increased. The results of dynamic mechanical analysis revealed that the storage modulus, loss modulus and glass transition temperature (Tg) of the polymer composites increased with increasing content of the nanophosphor powder. The microhardness data also confirmed that the hardness number increased with nanoparticles concentration in the PMMA nanocomposites. The obtained results revealed a relatively linear relationship between Tg and the Vickers hardness.

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Anitha, R., E. Kumar et S. C. Vella Durai. « Synthesis and Investigations of Structural, Optical and AC Conductivity Properties of PANI/CeO2 Nanocomposites ». Asian Journal of Chemistry 31, n^o 5 (28 mars 2019) : 1158–62. http://dx.doi.org/10.14233/ajchem.2019.21910.

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This paper explains the details on the preparation of polyaniline/CeO2 (10 wt %) nanocomposites using the method of in situ polymerization. The formation of PANI/CeO2 nanocomposites were proposed via oxidation of aniline and reduction of CeO2, respectively. The effect of CeO2 concentration on AC conductivity, morphological, optical and structural properties of the prepared PANI/CeO2 nanocomposites material were examined. The structural studies show the presence of CeO2 nanoparticles were occurred in PANI of nanocomposites. The average grain size of PANI/CeO2 nanocomposites varied with increasing and decreasing concentration due to the process of nucleation during the polymerization. The average particle grain sizes were measured from HRTEM. The morphology analysis was carried out from SEM. The UV absorption spectrum showed that the absorption peak of CeO2 nanoparticle at 341 nm, shifted to lower wavelength side, the nanocomposite absorption peaks at about 324, 368 and 858 nm was confirmed by the formation of PANI/CeO2 nanocomposites. The electronic structure of the band gap of the nanocomposite materials were calculated using ultraviolet visible absorption spectrum. The band gap energy of nanocomposite is 3.36 eV. The FTIR spectrum clearly showed the strong presence of CeO2 nanoparticles in PANI chain. The AC conductivity varied with varying the temperature and depends on the concentration due to the formation of PANI/CeO2 nanocomposite.

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Jawad, Yaqoob M., Mahasin F. Hadi Al-Kadhemy et Jehan Abdul Sattar Salman. « Synthesis Structural and Optical Properties of CMC/MgO Nanocomposites ». Materials Science Forum 1039 (20 juillet 2021) : 104–14. http://dx.doi.org/10.4028/www.scientific.net/msf.1039.104.

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Nanocomposites were prepared by the method of solution casting with different proportions of magnesium oxide nanoparticles (0, 1, 3, 5, 7 and 9) wt%. The structural and optical properties of nanocomposites of CMC/MgO have been studied. It was well known that the increased content of MgONPs in the method contributes to the peaks of MgONPs being completely integrated and/or disappearing within the CMC diffraction halos in the experimental results of XRD study. The differences in the XRD spectrum indicate that doping with nanoparticles induced a disparity in the microstructure of the polymer. Nanocomposite film scanning electron microscopy (SEM) reveals that MgONPs appear to form aggregates and scatter well in (CMC/MgO) nanocomposite films and at apply 9 wt. It forms a continuous network within the polymer for the percentage of MgONPs to (CMC) polymer. FTIR spectrum revealed the MgONPs has no destructive influence on the polymer structure as no covalent bonds formed between CMC and MgONPs. The optical properties of CMC/MgO nanocomposites were measured in wavelength range (200–900) nm. Experimental studies have shown that the absorbance, absorption coefficient, extinction coefficient, refractive index, actual and imaginary dielectric constant of CMC polymer is improved with an increase in concentrations of MgONPs in nanocomposites. The transmittance and energy gap of CMC polymer are decreased with the increase in the concentrations of MgONPs.

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Alam, Rabeya Binta, Md Hasive Ahmad, S. M. Nazmus Sakib Pias, Eashika Mahmud et Muhammad Rakibul Islam. « Improved optical, electrical, and thermal properties of bio-inspired gelatin/SWCNT composite ». AIP Advances 12, n^o 4 (1 avril 2022) : 045317. http://dx.doi.org/10.1063/5.0089118.

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In this study, we report a facile route to synthesize gelatin-based Single-Walled Carbon Nanotube (gelatin/SWCNT) nanocomposites using a simple solution casting process and investigate the impact of SWCNT filler on the structural, surface morphological, optical, electrical, and thermal features. According to the Fourier transform infrared spectroscopy study, the addition of SWCNTs improves the interaction between gelatin and SWCNTs. The field emission scanning electron microscope images showed the presence of the fillers increased with the increment of SWCNT. The roughness of the samples increased caused by high interfacial interactions between Gel and SWCNTs. The nanocomposite’s optical bandgap was observed to be reduced from 2.1 to 1.9 eV as the SWCNT was varied from 0% to 0.5 vol. %. The addition of SWCNTs significantly boosted the DC electrical conductivity of the prepared samples by four orders of magnitude. The incorporation of SWCNT into the gelatin matrix was also observed to improve the nanocomposite's melting enthalpy and degree of crystallinity up to 94.5%. The gelatin/SWCNT nanocomposites were found to be decomposed completely in 4 days in the soil in an open environment.

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Sharma, Deepali, B. S. Kaith et Jaspreet Rajput. « Single Step In Situ Synthesis and Optical Properties of Polyaniline/ZnO Nanocomposites ». Scientific World Journal 2014 (2014) : 1–13. http://dx.doi.org/10.1155/2014/904513.

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Polyaniline/ZnO nanocomposites were prepared by in situ oxidative polymerization of aniline monomer in the presence of different weight percentages of ZnO nanostructures. The steric stabilizer added to prevent the agglomeration of nanostructures in the polymer matrix was found to affect the final properties of the nanocomposite. ZnO nanostructures of various morphologies and sizes were prepared in the absence and presence of sodium lauryl sulphate (SLS) surfactant under different reaction conditions like in the presence of microwave radiation (microwave oven), under pressure (autoclave), under vacuum (vacuum oven), and at room temperature (ambient condition). The conductivity of these synthesized nanocomposites was evaluated using two-probe method and the effect of concentration of ZnO nanostructures on conductivity was observed. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and UV-visible (UV-VIS) spectroscopy techniques were used to characterize nanocomposites. The optical energy band gap of the nanocomposites was calculated from absorption spectra and ranged between 1.5 and 3.21 eV. The reported values depicted the blue shift in nanocomposites as compared to the band gap energies of synthesized ZnO nanostructures. The present work focuses on the one-step synthesis and potential use of PANI/ZnO nanocomposite in molecular electronics as well as in optical devices.

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AHMED, S. M., A. A. A. DARWISH, E. A. EL-SABAGH, N. A. MANSOUR, D. E. ABULYAZIED et E. S. ALI. « PHYSICOCHEMICAL PROPERTIES OF PREPARED ZnO/ POLYSTYRENE NANOCOMPOSITES : STRUCTURE, MECHANICAL AND OPTICAL ». Journal of Ovonic Research 16, n^o 1 (janvier 2020) : 71–81. http://dx.doi.org/10.15251/jor.2020.161.71.

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Nanocomposites of polystyrene nano sphere (PS) with different loading of nano zinc oxide (ZnO) were prepared by two different methods, blend and in situ method. The prepared films of the synthesized nanocomposites materials were characterized by energy dispersive investigation (EDX), X-ray diffraction (XRD) and the morphology of ZnO/PS nanocomposite were investigated by transmission electron microscope (TEM). Phase composition and microstructure analysis shows that ZnO nanoparticles content has an influence on the crystal structure and morphology of ZnO/PS nanocomposite. The effect of ZnO nanoparticles on linear optical properties was studied in the PS lattice. The obtained results indicate that, the refractive index has been increased while the energy gap decreased with increasing ZnO nanoparticles contents. The improving of mechanical properties of ZnO/PS nanocomposite is verified due to the addition of ZnO nanoparticles.

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Sudhakaran, Allwin, Ashwin Sudhakaran et E. Siva Senthil. « Study of Bandgap Energy of Novel Nanocomposite ». International Journal of Recent Technology and Engineering (IJRTE) 10, n^o 4 (30 novembre 2021) : 171–76. http://dx.doi.org/10.35940/ijrte.d6607.1110421.

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In this novel work, we have studied the optical properties of CuBaM-CZFO nanocomposites. (Cu0.5Ba0.5Fe12O19)1-x/ (Co0.6Zn0.4 Fe2O4) x [where x=0.1,0.2] nanocomposites were synthesized individually by sol-gel citrate method and then made into nanocomposites by physical mixing technique. Further characterization over their structural, morphological and optical properties were carried out in detail. With the help of UV analysis, the optical properties such as, the band gap energy was discovered which is found using Tauc’s plot. The bandgap energy is 2.6503eV for CuBaM-CZFO 90-10 which is lesser than CuBaM-CZFO 80-20 (2.8456eV). The structural, morphological and optical properties of novel CuBaM-CZFO nanocomposite are reported and compared with, both among themselves and from the literature review.

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Murugadoss, G., M. Rajesh Kumar, R. Jothi Ramalingam, Hamad Al-Lohedan, A. Ramesh Babu, A. Kathalingam et Ahmed M. Tawfeek. « Synthesis and study on optical properties of CeO2-Mg(OH)2 and inverted Mg(OH)2-CeO2 nanocomposites ». Digest Journal of Nanomaterials and Biostructures 16, n^o 4 (décembre 2021) : 1427–32. http://dx.doi.org/10.15251/djnb.2021.164.1427.

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Well-crystalline CeO2-Mg(OH)2 and inverted Mg(OH)2-CeO2 nanocomposites were successfully synthesized by a facile ‘one-pot’ chemical precipitation method at low temperature. The crystal structure, morphology and optical properties of the CeO2- Mg(OH)2 and inverted Mg(OH)2-CeO2 nanocomposites were investigated using X-ray diffraction, TEM, FTIR, UV-vis absorption and PL spectrometer. The photoluminescence study revealed visible light emission for the nanocomposite. Interestingly, significant red shift observed for Mg(OH)2-CeO2 nanocomposites. The optical tuning nanocomposites can be used for the optoelectronic applications.

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Ivkov, Sergey A., Konstantin A. Barkov, Evelina P. Domashevskaya, Elena A. Ganshina, Dmitry L. Goloshchapov, Stanislav V. Ryabtsev, Alexander V. Sitnikov et Pavel V. Seredin. « Nonlinear Transport and Magnetic/Magneto-Optical Properties of Cox(MgF2)100-x Nanostructures ». Applied Sciences 13, n^o 5 (26 février 2023) : 2992. http://dx.doi.org/10.3390/app13052992.

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The aim of this work was to comprehensively study the effect of the variable atomic composition and structural-phase state of Cox(MgF2)100-x nanocomposites on their nonlinear transport and magnetic/magneto-optical properties. Micrometer-thick nanocomposite layers on glass substrates were obtained by means of ion-beam sputtering of a composite target in the argon atmosphere in a wide range of compositions (x = 16–59 at.%). Using a low metal content in the nanocomposite, magnesium fluoride was kept in the nanocrystalline state. As the metal content increased, nanocrystalline cobalt was formed. The value of the resistive percolation threshold, xper = 37 at.%, determined from the concentration dependences of the electrical resistance of the nanocomposites coincided with the beginning of nucleation of the metallic nanocrystals in the MgF2 dielectric matrix. The absolute value of the maximum negative magnetoresistive effect in the nanocomposites was 5% in a magnetic field of 5.5 kG at a Co concentration of x = 27 at.%.

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Tamborra, M., M. Striccoli, M. L. Curri et A. Agostiano. « Hybrid Nanocomposites Based on Luminescent Colloidal Nanocrystals in Poly(methyl methacrylate) : Spectroscopical and Morphological Studies ». Journal of Nanoscience and Nanotechnology 8, n^o 2 (1 février 2008) : 628–34. http://dx.doi.org/10.1166/jnn.2008.a088.

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We report on preparation process and optical characterization of a nanocomposite material obtained dispersing colloidal semiconductor nanocrystals (NCs), namely CdS and CdSe@ZnS core–shell system in poly(methyl methacrylate) (PMMA). Such method allows a large flexibility on nanocrystal materials and on the choice of the polymer characteristics. Nanocomposite thin films were extensively investigated by means optical and morphological techniques. The effects on NC composition, concentration, size, and surface chemistry on the spectroscopical and structural behaviour of the nanocomposite properties were studied. The NC size dependent optical properties of the nanocomposites are mainly accounted by the NC composition and size, while the morphology of the films is explained on the base of the NC surface characteristics and their concentration in the nanocomposites.

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Mohaimeed, Ameen alwan. « The Study the Influence of TiO2-Nanoparticles Doped in Polyvinyl Alcohol by Measuring Optical Properties of PVA Films ». Iraqi Journal of Nanotechnology, n^o 3 (14 octobre 2022) : 59–70. http://dx.doi.org/10.47758/ijn.vi3.62.

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It was investigated how titanium dioxide nanoparticles affected the optical properties of polyvinyl alcohol. Polymer nanocomposites (PVA-TiO2) are created via stirring and casting. The results demonstrate that transmittance improves from 75% to 95% while titanium dioxide concentration enhances the absorbance of nanocomposites. Nanocomposite films made of PVA and TiO2 had reflectance values of 12 and 16 percent (weight percent=0.15 and 0.85%).The refractive index and coefficient of extinction rise with increasing density, and optical absorption and photon dispersion in the nanocomposite (PVA-TiO2) also rise as the concentration of titanium dioxide nanoparticles rises. Real dielectric (r) and imaginary dielectric I constants also rise as titanium dioxide nanoparticle concentration does. The results show that when the weight % of (TiO2) nanoparticles increased, the energy gap decreased from 3.32 to 2.23. Additionally, optical conductivity increased with the concentration of (TiO2) NPs. Nanocomposites of PVA and TiO2 are essential for optical applications.

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Kandulna, R., U. Das, Ms Rimpi, B. Kachhap et N. Prasad. « Hybrid Polymeric Nanocomposites Based High Performance Oleds : A Review ». Shodh Sankalp Journal 1, n^o 3 (1 septembre 2021) : 16–34. http://dx.doi.org/10.54051/shodh.2021.1.3.1.

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This review reports the recent significant progress for achieving the synthesis of various types of polymer-based nanocomposites and understanding of the basic principle which determine their optical, electronic and magnetic properties. Some of the polymeric nanocomposite materials show remarkable electrical as well as optical properties regarding towards interest for applications in OLEDs. Nanoparticles which are basically inorganic, plays important role in the opto-electronic field. A nanoparticle with conjugate polymer matrix makes polymer nanocomposite and that nanocomposite used as an active emissive layer between the structures of optoelectronic device like OLEDs, OPVs etc. Application of such polymeric nanocomposite materials are discussed in this present communication with their success and failure, towards their optical as well as electrical properties in the fabrication of OLEDs.

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Pavlenko, Mykola, Valerii Myndrul, Gloria Gottardi, Emerson Coy, Mariusz Jancelewicz et Igor Iatsunskyi. « Porous Silicon-Zinc Oxide Nanocomposites Prepared by Atomic Layer Deposition for Biophotonic Applications ». Materials 13, n^o 8 (24 avril 2020) : 1987. http://dx.doi.org/10.3390/ma13081987.

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In the current research, a porous silicon/zinc oxide (PSi/ZnO) nanocomposite produced by a combination of metal-assisted chemical etching (MACE) and atomic layer deposition (ALD) methods is presented. The applicability of the composite for biophotonics (optical biosensing) was investigated. To characterize the structural and optical properties of the produced PSi/ZnO nanocomposites, several studies were performed: scanning and transmission electron microscopy (SEM/TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), diffuse reflectance, and photoluminescence (PL). It was found that the ALD ZnO layer fully covers the PSi, and it possesses a polycrystalline wurtzite structure. The effect of the number of ALD cycles and the type of Si doping on the optical properties of nanocomposites was determined. PL measurements showed a “shoulder-shape” emission in the visible range. The mechanisms of the observed PL were discussed. It was demonstrated that the improved PL performance of the PSi/ZnO nanocomposites could be used for implementation in optical biosensor applications. Furthermore, the produced PSi/ZnO nanocomposite was tested for optical/PL biosensing towards mycotoxins (Aflatoxin B1) detection, confirming the applicability of the nanocomposites.

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Doğan, Mehmet, Hatice Yüksel et Berna Koçer Kizilduman. « Characterization and thermal properties of chitosan/perlite nanocomposites ». International Journal of Materials Research 112, n^o 5 (1 mai 2021) : 405–14. http://dx.doi.org/10.1515/ijmr-2020-8007.

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Abstract In this study, chitosan/perlite nanocomposites were synthesized using the solvent casting method and then characterized using Fourier transform infrared spectroscopy, X-ray diffraction, optical contact angle, differential thermal analysis/thermogravimetry, differential scanning calorimetry, atomic force microscopy, transmission electron microscopy and Zetasizer NanoS devices. Perlite was determined to be dispersed in nano size and homogeneously in the chitosan matrix. Chitosan/perlite nanocomposite was generally more thermally stable compared to pure chitosan polymer. The fact that the amount of perlite in the nanocomposite increased showed that the hydrophilic properties of nanocomposites increased. In addition, antibacterial activities of the samples were investigated using the agar-disk diffusion method and hemocompatibility testing was also performed.

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Kadhim, Mohammed Abdul, et Ehssan Al-Bermany. « New fabricated PMMA-PVA/graphene oxide nanocomposites : Structure, optical properties and application ». Journal of Composite Materials 55, n^o 20 (3 mars 2021) : 2793–806. http://dx.doi.org/10.1177/0021998321995912.

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Graphene oxide nanosheets (GO) bring more interest in the tunable bandgap and enhanced the optical properties of nanocomposites. The developed method successfully mixed the PMMA- dissolved in dimethylformamide (DMF) with PVA dissolved in distilled water (DW) and DMF. New (PMMA-DMF)-(PVA-DW-DMF)/GO nanocomposite was successfully fabricated with various loading ratios of GO nanosheets for the first time. Several factors were applied to get fine desperation and homogeneous using the acoustic-solution casting method. Optical Microscope (OM), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and UV–visible spectrophotometer were applied to investigate the structure and optical properties of the PMMA-PVA-GO nanocomposite. The OM images confirmed the fine homogenous matrix and GO distribution in the nanocomposites. FTIR spectra exhibited the most functional group of polymers and GO in the nanocomposites and strong interfacial interaction between the GO and matrix as confirmed by the shifting in the XRD patterns of the PMMA. The optical properties results of the PMMA-PVA/GO nanocomposites revealed an improvement up to 400% of the absorbance, 337% of the absorption coefficient, 51% of the refractive index, 210% of the real and 125% of the imaginary dielectric constants in terms to increase the GO concentrations, whereas the reduction in the transmittance and energy bandgap results of allowed and forbidden indirect transition were exhibited up to 9 and 16.4%, respectively. These results could grow for better and wide applications such as radiation shielding, specific optoelectronic applications, and filters ultraviolet also could use in landfilling the chemical, nuclear, and radioactive waste.

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ANANDAN, K., K. RAJESH, K. GAYATHRI, ANITHA REXALIN DEVARAJ, M. MOHANBABU et P. PRABHAKAR RAO. « Optical Properties of Heterostructured ZnO/NiO Nanocomposites Synthesized via Facile Precipitation Process ». Asian Journal of Chemistry 35, n^o 9 (31 août 2023) : 2171–75. http://dx.doi.org/10.14233/ajchem.2023.27794.

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The semiconductor zinc oxide/nickel oxide (ZnO/NiO) heterostructured nanocomposites have been successfully synthesized via facile and eco-friendly homogeneous precipitation process with ethanol and water as solvents. The prepared nanocomposites were studied by means of structural and optical characteristics by using X-ray diffraction, ultraviolet visible absorption and photoluminescence emission spectro-scopies. The peaks in the XRD pattern attributed to the hexagonal wurtzite structure of ZnO and face-centered cubic structure of NiO, as a result the XRD analysis further confirmed that the solvents play a powerful role in size of the crystallite of the synthesized nanocomposites. Strong UV absorption may be seen in UV-vis absorbance spectra and samples of ZnO/NiO nanocomposite materials had greater energy gap (Eg) values than those of pure NiO and ZnO materials. The synthesized materials have demonstrated high photoluminescence emission in UV-blue region in the range of 241-498 nm, it might be a valuable source for future display applications. According to the aforementioned finding, the ZnO/NiO nanocomposites showed significant promise and were a viable material for optoelectronic devices.

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Joshi, Hira, et S. Annapoorni. « Tuning Optical Properties in Nanocomposites ». International Journal of Nanoscience 19, n^o 04 (12 février 2020) : 1950026. http://dx.doi.org/10.1142/s0219581x19500261.

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Metal nanostructures and noble metal-based nanostructures, in particular, exhibit plasmonic resonance in the visible region. The resonance absorption can be tuned by varying the size of nanoparticle and the external matrix in which the plasmonic materials are embedded. Mie’s theory has been used to demonstrate the shift in the plasmonic resonance in gold nanoparticles embedded in different dielectric media. Two model systems, viz. Au–ZnO and Au–Al2O3, prepared by sputtering on quartz substrates were used to study the optical absorption. The plasmonic peaks were observed to be red shifted in Au–Al2O3 and Au–ZnO, as is also supported by Mie formalism. The dielectric constant of the external matrix viz., Al2O3 and ZnO, estimated using the experimental and the Mie simulations are 3.05 and 1.83, respectively.

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Srivastava, S., M. Haridas et J. K. Basu. « Optical properties of polymer nanocomposites ». Bulletin of Materials Science 31, n^o 3 (juin 2008) : 213–17. http://dx.doi.org/10.1007/s12034-008-0038-9.

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Run, Ming Tao, Qing Chang Zhang, Wen Zhou et Yu Zhong. « Crystal Morphology and Thermal Properties of PTT/POE/OMMT Nanocomposites ». Solid State Phenomena 181-182 (novembre 2011) : 39–42. http://dx.doi.org/10.4028/www.scientific.net/ssp.181-182.39.

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The crystal morphology, melt-crystallization and mechanical properties of poly (trimethylene terephthalate)/maleinized poly (octene-ethylene)/organo-montmorillonite nanocomposites were investigated by using polarized optical microscopy (POM), differential scanning calorimetry (DSC) and universal material testing machine, respectively. The results suggest that the nanocomposites form smaller or imperfect microcrystallites with lower melting point due to the influence of OMMT components and the nanocomposites have increased crystallization rate because OMMT is an effective nucleation agent. However, the crystallinity decreases because of the thickening effect of OMMT in the composites. The nanocomposite with 2%OMMT has the largest tensile and impact strength.

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Rahmatpanah, Zahra, Mir Mohammad Alavi Nikje et Maryam Dargahi. « Optical Active Thermal Stable Nanocomposites Using Polybutadiene-Based Polyurethane and Graphene Quantum Dot-MnO2 ». International Journal of Polymer Science 2022 (7 avril 2022) : 1–13. http://dx.doi.org/10.1155/2022/2377803.

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Synthesis and characterization of new polybutadiene-based polyurethane, graphene quantum dot-MnO2 nanoparticles, and relative nanocomposites were set as the aim of current artwork. For this purpose, a one-pot polymerization approach was employed in preparation of polyurethane through the reaction of amine polyol and toluene diisocyanate (TDI) in presence of DBTDL catalyst. Nanocomposites were synthesized using 1 to 3 incorporation percent of graphene quantum dot-MnO2 nanoparticles in polymer matrix. 1H-NMR and FT-IR spectroscopies confirmed successful synthesis of reaction products including graphene quantum dot-MnO2, polyurethane, and nanocomposites. UV-vis and PL spectrophotometry techniques were applied for achieving optical information of samples. Optical properties of nanocomposites were reserved properly with no great quenching. Thermal stabilities, degradation rates, and thermal characteristics of polyurethane and nanocomposites were investigated using TGA/DTG and DSC analysis. Thermal stability showed direct relationship to nanoparticle content, and 3%wt nanocomposite showed improved thermal behaviour in comparison with pure PU. SEM, XRD, and AFM techniques proved successful nanocomposite synthesis with detecting nanoparticle species and fine nanoparticle dispersion with improved topographic and morphologic characteristics making GQD-MnO2 polyurethane nanocomposites a good candidate for using in optical active and thermal stable coatings.

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Irimpan, Litty, V. P. N. Nampoori et P. Radhakrishnan. « Enhanced luminescence and nonlinear optical properties of nanocomposites of ZnO–Cu ». Journal of Materials Research 23, n^o 11 (novembre 2008) : 2836–45. http://dx.doi.org/10.1557/jmr.2008.0364.

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In this article, we present the spectral and nonlinear optical properties of ZnO–Cu nanocomposites prepared by colloidal chemical synthesis. The emission consisted of two peaks. The 385-nm ultraviolet (UV) peak is attributed to ZnO and the 550-nm visible peak is attributed to Cu nanocolloids. Obvious enhancement of UV and visible emission of the samples is observed and the strongest UV emission of a typical ZnO–Cu nanocomposite is over three times stronger than that of pure ZnO. Cu acts as a sensitizer and the enhancement of UV emission are caused by excitons formed at the interface between Cu and ZnO. As the volume fraction of Cu increases beyond a particular value, the intensity of the UV peak decreases while the intensity of the visible peak increases, and the strongest visible emission of a typical ZnO–Cu nanocomposite is over ten times stronger than that of pure Cu. The emission mechanism is discussed. Nonlinear optical response of these samples is studied using nanosecond laser pulses from a tunable laser in the wavelength range of 450–650 nm, which includes the surface plasmon absorption (SPA) band. The nonlinear response is wavelength dependent and switching from reverse saturable absorption (RSA) to saturable absorption (SA) has been observed for Cu nanocolloids as the excitation wavelength changes from the low absorption window region to higher absorption regime near the SPA band. However, ZnO colloids and ZnO–Cu nanocomposites exhibit induced absorption at this wavelength. Such a changeover in the sign of the nonlinearity of ZnO–Cu nanocomposites, with respect to Cu nanocolloids, is related to the interplay of plasmon band bleach and optical limiting mechanisms. The SA again changes back to RSA when we move over to the infrared region. The ZnO–Cu nanocomposites show self-defocusing nonlinearity and good nonlinear absorption behavior. The nonlinear refractive index and the nonlinear absorption increases with increasing Cu volume fraction at 532 nm. The observed nonlinear absorption is explained through two-photon absorption followed by weak free-carrier absorption and interband absorption mechanisms. This study is important in identifying the spectral range and composition over which the nonlinear material acts as a RSA-based optical limiter. ZnO–Cu is a potential nanocomposite material for the light emission and for the development of nonlinear optical devices with a relatively small limiting threshold.

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Ramazanov, M. A., A. M. Rahimli et F. V. Hajiyeva. « The influence of titanium dioxide (TiO2) nanoparticles on the structure, optical and dielectric properties of polyvinyl chloride (PVC) ». Modern Physics Letters B 34, n^o 28 (10 juin 2020) : 2050310. http://dx.doi.org/10.1142/s0217984920503108.

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The tendency to improve the properties of insulating materials by incorporating inorganic nanoparticles has become necessary in order to design new insulation systems. In this study, PVC/TiO2-based nanocomposites with different loadings (3, 5 and 10 wt.%) of TiO2 nanoparticles were prepared by the solution mixing method. The morphology of the prepared nanocomposites was studied by Atomic Force Microscope (AFM). Experimentally, it was found that as the concentration increases, the size of the surface structural elements and particle size increases. Photoluminescence (PL) analysis of samples shows improvement compared to the pristine polymer. Furthermore, PL intensity for nanocomposites increases depending on the concentration and saturation occurs at a certain amount of titanium dioxide nanoparticles. The increase in luminescence intensity till a certain nanoparticle content is due to the growth of the luminescent surface area. Further saturation is explained by the increase in particle size with no increase or a slight reduction in surface area. Dielectric properties of nanocomposites were studied. It was found that dielectric permittivity of the materials increases as the nanoparticle volume content increases and it reaches at its highest value for the nanocomposites with 3% nanoparticle content. The optical properties of the polymer and nanocomposite films were studied in the region 200 nm to 600 nm. It was found that the PVC/TiO2 nanocomposites showed enhancement in the absorbance intensities which was more significant for the nanocomposites with higher nanoparticle content compared to the pristine polymer. Furthermore, absorption spectra were used to calculate the optical bandgap of the prepared nanocomposite films and redshift observed in the calculated values of bandgap for nanocomposites. Consequently, it was proved that by incorporating TiO2 nanoparticles into the polymer matrix, the spectral region of the samples can be expanded resulting in broadened application of such systems in various fields of science and technology.

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Al-Qahtani, W. H., G. Murugadoss, K. Narthana, M. R. Kumar, J. R. Rajabathar et A. Kathalingam. « Structural, morphological, optical and electrochemical characterization of Ag2O/ZnO and ZnO/Ag2O nanocomposites ». Journal of Ovonic Research 18, n^o 2 (12 avril 2022) : 187–94. http://dx.doi.org/10.15251/jor.2022.182.187.

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In this paper, well-crystalline Ag2O/ZnO and ZnO/Ag2O nanocomposites were prepared by a facile chemical method. Structural, morphological and optical properties of the nanocomposite were studied using various advanced characterization techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), UV-Visible (UVVis) and photoluminescence (PL) spectroscopy. The Ag2O and ZnO were clearly identified in the composite from SEM and TEM. Significant shifting observed in the both UV-Vis and PL spectroscopy. In addition, electrocatalytic activity of the Ag2O/ZnO and ZnO/Ag2O nanocomposites studied by an electrochemical workstation. The ZnO/Ag2O nanocomposites showed better optical and electrochemical properties due to decorating the low-band gap Ag2O on the surface of hexagonal structure ZnO nanoparticles.

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Al-Hussein, Fatimah T., et Bahaa H. Rabee. « Optical Properties of (PS-TiO2-Al2O3) Nanocomposite Films Injected with Air Nano Bubbles ». NeuroQuantology 20, n^o 3 (26 mars 2022) : 01–07. http://dx.doi.org/10.14704/nq.2022.20.3.nq22032.

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In this work, the optical properties of (PS-TiO2-Al2O3) nanocomposites films prepared by casting method have studied. To use in different optical fields. The TiO2 and Al2O3 nano particles added with different weight percentages are (1,2, 3 and 4) wt% were injected air bubbles to generate Nano bubbles in the (PS-TiO2-Al2O3) nanocomposites. The results revealed that absorbance, absorption coefficient, extinction coefficient, and refractive index of the optical characteristics of nanocomposites for wavelength range (280-800) nm. Increase with increase TiO2 and Al2O3concentrations, while the Transmittance decreased with increase TiO2 and Al2O3 concentrations. Optical energy values gap from (3.62 – 1.50) eV, where the optical energy gap of produced films reduced as the number of TiO2 and Al2O3 nanoparticles increased.

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Al-Asbahi, Bandar Ali, Mohammad Hafizuddin Haji Jumali et Rashad Al-Gaashani. « Efficient Charge Transfer Mechanism in Polyfluorene/ZnO Nanocomposite Thin Films ». Journal of Nanomaterials 2014 (2014) : 1–8. http://dx.doi.org/10.1155/2014/608572.

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The optical properties and charge transfer mechanism of poly (9,9′-di-n-octylfluorenyl-2.7-diyl) (PFO)/ZnO thin films have been investigated. The ZnO nanorods (NRs) were prepared via a microwave technique. The solution blending method was used to prepare the PFO/ZnO nanocomposites. X-ray diffraction (XRD) and field emission scanning electron microscope (FE-SEM) were used to determine the structural properties, while UV-Vis and photoluminescence (PL) were employed to investigate the optical properties of the films. XRD patterns confirmed that there was no variation in the structure of both PFO and ZnO NRs due to the blending process. FE-SEM micrographs displayed that ZnO NRs were well coated by PFO in all nanocomposite films. The absorption spectra of the nanocomposite thin films exhibited a red-shift indicating the increment in conjugation length of the PFO/ZnO nanocomposite. Significant quenching in the emission intensity of PFO was observed in fluorescence spectra of the nanocomposite films. This quenching was attributed to efficient charge transfer in the PFO/ZnO nanocomposites, which was further supported by the shorter PL lifetime of PFO/ZnO than that of the PFO thin film. The continuous decline in PL intensity of these nanocomposites is attributed to homogenous dynamic quenching between PFO and ZnO NRs.

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Hao, Yu, Lan Yang, Jinze Li, Ruonan Xing et Yuzong Gu. « Third-order nonlinear optical properties of CuS/reduced graphene oxide nanocomposites ». European Physical Journal Applied Physics 94, n^o 2 (mai 2021) : 20401. http://dx.doi.org/10.1051/epjap/2021200278.

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CuS/Reduced graphene oxide (rGO) nanocomposites can be synthesized using the hydrothermal method. X-ray diffraction and transmission electron microscopy analyses demonstrated that CuS uniformly covered the surfaces of rGO. In this paper, the nonlinear optical (NLO) properties of the CuS/rGO composites with different graphene content were investigated by a Z-scan technique. The results show that while reverse saturable absorption (RSA) is prominent in pristine CuS, saturable absorption (SA) is dominant in pristine rGO. A transition from RSA to SA is seen when the graphene content is increased in the CuS/rGO nanocomposite. The measurements results show that the improvement of nonlinearity is related to the synergistic effect between two or more materials. The research content in this paper can establishes a foundation for further study of CuS/rGO nanocomposites application in NLO devices.

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Vodnik, Vesna V., Dušan K. Božanić, Nataša Bibić, Zoran V. Šaponjić et Jovan M. Nedeljković. « Optical Properties of Shaped Silver Nanoparticles ». Journal of Nanoscience and Nanotechnology 8, n^o 7 (1 juillet 2008) : 3511–15. http://dx.doi.org/10.1166/jnn.2008.144.

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The influence of shape and dielectric property of surrounding media on surface plasmon absorption band of silver nanoparticles was studied. Spherical silver nanoparticles (d = 5.6 nm) synthesized in water using NaBH4 as a reducing agent are transferred in non-polar solvent (chloroform) with phase-transfer reagent oleylamine. The absorption spectrum of oleylamine-capped silver nanoparticles dispersed in chloroform shows a strong surface plasmon resonance band that is 19 nm red-shifted compared to unmodified particles in water. The values for peak position and corresponding half widths are compared with theoretical calculations based on Mie theory. Prismatic and plate-like silver nanoparticles were synthesized in water using trisodium citrate as a reducing agent and cetyltrimethylammonium bromide as stabilizer. Due to structural anisotropy of prismatic and plate-like silver nanoparticles three surface plasmon resonance bands were observed in absorption spectrum. Nanocomposites consisting of non-spherical silver nanoparticles and polyvinyl alcohol exhibit different optical properties compared to water colloid. Instead of three surface plasmon bands, nanocomposite film has only one peak at 460 nm. Reason for appearance of single surface plasmon resonance band in nanocomposite film was discussed according to Maxwell-Garnet theory.

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Tripathi, S. K., Jagdish Kaur et Ramneek Kaur. « Photoluminescence Studies in II-VI Nanoparticles Embedded in Polymer Matrix ». Defect and Diffusion Forum 357 (juillet 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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Olszewski, Adam, Aleksandra Ławniczak, Paulina Kosmela, Marcin Strąkowski, Aleksandra Mielewczyk-Gryń, Aleksander Hejna et Łukasz Piszczyk. « Influence of Surface-Modified Montmorillonite Clays on the Properties of Elastomeric Thin Layer Nanocomposites ». Materials 16, n^o 4 (17 février 2023) : 1703. http://dx.doi.org/10.3390/ma16041703.

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In recent years, polyurethane nanocomposites have attracted more attention due to the massive demand for materials with increasingly exceptional mechanical, optical, electrical, and thermal properties. As nanofillers have a high surface area, the interaction between the nanofiller and the polymer matrix is an essential issue for these materials. The main aim of this study is to validate the impact of the montmorillonite nanofiller (MMT) surface structure on the properties of polyurethane thin-film nanocomposites. Despite the interest in polyurethane–montmorillonite clay nanocomposites, only a few studies have explored the impact of montmorillonite surface modification on polyurethane’s material properties. For this reason, four types of polyurethane nanocomposites with up to 3% content of MMT were manufactured using the prepolymer method. The impact of montmorillonites on nanocomposites properties was tested by thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA), contact angle measurement, X-ray diffraction (XRD), and optical coherence tomography (OCT). The results showed that chemical and physical interactions between the polymer matrix and functional groups on the montmorillonite surface have a considerable impact on the final properties of the materials. It was noticed that the addition of MMT changed the thermal decomposition process, increased T2% by at least 14 °C, changed the hydrophilicity of the materials, and increased the glass transition temperature. These findings have underlined the importance of montmorillonite surface structure and interactions between nanocomposite phases for the final properties of nanocomposites.

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Chumachenko, V. A., A. P. Naumenko, O. A. Yeshchenko, N. V. Kutsevol et I. S. Bondarchuk. « Synthesis, Morphology, and Optical Properties of Au/CdS Hybrid Nanocomposites Stabilized by Branched Polymer Matrices ». Journal of Nanomaterials 2016 (2016) : 1–9. http://dx.doi.org/10.1155/2016/1439437.

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Metal/semiconductor (Au/CdS) nanocomposites were synthesized in the solution of branched D-g-PAA polymer. TEM and DLS of Au/CdS/D-g-PAA nanocomposites revealed complicated nanocomposite structure consisting of the Au nanoparticles (NPs) of 6 nm in size surrounded by small CdS NPs with size of 3 nm. These nanocomposites formed the aggregates-clusters with average size of 50–800 nm. Absorption spectra of Au/CdS nanocomposites consist of the bands of excitons in CdS NPs and surface plasmons in Au ones. The surface plasmon band of gold NPs is red shifted and broadened in Au/CdS/D-g-PAA nanocomposites comparing to the one of Au NPs in Au/D-g-PAA proving the fact of close location of CdS and Au NPs in the synthesized Au/CdS/D-g-PAA nanocomposites. The PL spectra of Au/CdS nanocomposites originate from the radiative transitions in excitons in CdS NPs. The 4-fold increase of intensity of free exciton PL is observed for CdS NPs in Au/CdS/D-g-PAA comparing to CdS ones in CdS/D-g-PAA that is due to PL enhancement by local field of surface plasmons of Au NPs. Also, the 12-fold decrease of intensity of localized exciton PL is observed for CdS NPs in Au/CdS/D-g-PAA comparing to CdS ones in CdS/D-g-PAA. Most probably, it is due to passivation of the surface of CdS NPs carried out by the Au ones.

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Бурункова, Ю. Э., Д. Альхалил et Д. С. Свяжина. « Повышение эффективности полимерного нанокомпозита для формирования фотонных структур методом оптической записи ». Журнал технической физики 128, n^o 10 (2020) : 1512. http://dx.doi.org/10.21883/os.2020.10.50023.167-20.

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In this work, the conditions for optimizing an optical recording material based on photosensitive acrylate-urethane nanocomposites with silicon oxide nanoparticles, for efficient Bragg gratings recording by multibeam interference method is presented. It was shown that the choice of the most effective monomers and their concentrations in the nanocomposite which depends on their structure and polymerization rate, followed by determination of the optimal recording radiation intensity for the given composition, makes it possible to adjust the conditions for component diffusion and redistribution, and hence, the formation of regions with different refractive indices in the recording medium. These results can be useful for creating complex 2D and 3D photonic structures based on the targeted modification of photosensitive polymer nanocomposites with different properties (luminescent, nonlinear optical, etc.).

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Yurasov, A. N., et M. M. Yashin. « Accounting for the influence of granule size distribution in nanocomposites ». Russian Technological Journal 8, n^o 2 (14 avril 2020) : 59–66. http://dx.doi.org/10.32362/2500-316x-2020-8-2-59-66.

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This paper discusses the effect of the distribution of the granules size in nanocomposites on physical properties within the framework of the quasi-classical size effect. Methods of effective medium for describing nanocomposites are discussed. This paper also notes and discusses the contribution of various mechanisms that affect the optical and magneto-optical properties of such structures, especially in the IR region of the spectrum, where the quasi-classical dimensional effect is most pronounced. The Droude-Lorentz mode describes the contribution of the dimensional effect to the diagonal and non-diagonal components of the effective medium's permittivity tensor. The lognormal distribution of the granule size characteristic of many nanostructures is considered. Based on this approach, the dependences of the standard deviation on the value of the integral as a function of the average size of the granules were obtained. Based on the normalization condition, the numerical value of the standard deviation of the r values and the average particle size were analytically determined. This paper also discusses the fundamental significance of the results obtained – the possibility of applying this approach to all possible distributions. The found value of the average size of nanocomposite granules makes it possible to model various properties of nanocomposite structures, first of all, optical and magneto-optical properties, with the help of known methods within the framework of the effective medium approximation. This is especially important for describing the percolation transition in nanocomposites. The problem being solved is important and relevant, since many interesting and important effects are realized in such magnetic nanocomposites, such as the magneto-optical Kerr effect, the anomalous Hall effect, the giant magnetoresistance, and many others. The results obtained allow us to better describe materials that are widely used in modern electronics and nanoelectronics.

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Habib, Shaimaa A., Mona B. Mohamed, Samia A. Saafan et Talaat M. Meaz. « Synthesis, characterization and promising properties of Fe3O4/CdSe nanocomposite ». EPJ Web of Conferences 201 (2019) : 02002. http://dx.doi.org/10.1051/epjconf/201920102002.

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Nowadays there is a continuously increasing worldwide concern for the utilization of magnetic semiconductor nanocomposites. We synthesized bifunctional magnetic–luminescent nanocomposites with Fe3O4 nanoparticles as the cores and CdSe as the shells by a facile direct precipitation method. Transmission electron microscopy (TEM) images revealed that the obtained bifunctional nanocomposites had a core–shell structure, in a spherical shape with a particle radius of about 10.3nm, and the shell thickness of about 2.2nm. The flower shape is due to the inhomogeneous growth of CdSe due to the presence of many active sites which turn to be nucleation centers for the CdSe on the surface of the nano-magnetite. The X-ray diffraction (XRD) patterns showed a cubic spinel structure of the Fe3O4 core. Magnetic measurements indicated that the presence of CdSe in the composite reduces its magnetic properties. Optical measurements of the Fe3O4/CdSe nanocomposite show that the prepared samples have dual functions, optical tunable band gap of the semiconductor quantum dots and the magnetic properties of magnetite. This type of composites would be considered as dilute magnetic semiconductors (DMS).

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Kuriakose, Sini, D. K. Avasthi et Satyabrata Mohapatra. « Effects of swift heavy ion irradiation on structural, optical and photocatalytic properties of ZnO–CuO nanocomposites prepared by carbothermal evaporation method ». Beilstein Journal of Nanotechnology 6 (10 avril 2015) : 928–37. http://dx.doi.org/10.3762/bjnano.6.96.

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ZnO–CuO nanocomposite thin films were prepared by carbothermal evaporation of ZnO and Cu, combined with annealing. The effects of 90 MeV Ni7+ ion irradiation on the structural and optical properties of ZnO–CuO nanocomposites were studied by using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), UV–visible absorption spectroscopy and Raman spectroscopy. XRD studies showed the presence of ZnO and CuO nanostructures in the nanocomposites. FESEM images revealed the presence of nanosheets and nanorods in the nanocomposites. The photocatalytic activity of ZnO–CuO nanocomposites was evaluated on the basis of degradation of methylene blue (MB) and methyl orange (MO) dyes under sun light irradiation and it was observed that swift heavy ion irradiation results in significant enhancement in the photocatalytic efficiency of ZnO–CuO nanocomposites towards degradation of MB and MO dyes. The possible mechanism for the enhanced photocatalytic activity of ZnO–CuO nanocomposites is proposed. We attribute the observed enhanced photocatalytic activity of ZnO–CuO nanocomposites to the combined effects of improved sun light utilization and suppression of the recombination of photogenerated charge carriers in ZnO–CuO nanocomposites.

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Patel, Mitul, Daniel Schwendemann, Giorgia Spigno, Shiyu Geng, Linn Berglund et Kristiina Oksman. « Functional Nanocomposite Films of Poly(Lactic Acid) with Well-Dispersed Chitin Nanocrystals Achieved Using a Dispersing Agent and Liquid-Assisted Extrusion Process ». Molecules 26, n^o 15 (28 juillet 2021) : 4557. http://dx.doi.org/10.3390/molecules26154557.

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The development of bio-based nanocomposites is of high scientific and industrial interest, since they offer excellent advantages in creating functional materials. However, dispersion and distribution of the nanomaterials inside the polymer matrix is a key challenge to achieve high-performance functional nanocomposites. In this context, for better dispersion, biobased triethyl citrate (TEC) as a dispersing agent in a liquid-assisted extrusion process was used to prepare the nanocomposites of poly (lactic acid) (PLA) and chitin nanocrystals (ChNCs). The aim was to identify the effect of the TEC content on the dispersion of ChNCs in the PLA matrix and the manufacturing of a functional nanocomposite. The nanocomposite film’s optical properties; microstructure; migration of the additive and nanocomposites’ thermal, mechanical and rheological properties, all influenced by the ChNC dispersion, were studied. The microscopy study confirmed that the dispersion of the ChNCs was improved with the increasing TEC content, and the best dispersion was found in the nanocomposite prepared with 15 wt% TEC. Additionally, the nanocomposite with the highest TEC content (15 wt%) resembled the mechanical properties of commonly used polymers like polyethylene and polypropylene. The addition of ChNCs in PLA-TEC15 enhanced the melt viscosity, as well as melt strength, of the polymer and demonstrated antibacterial activity.

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Etrich, Christoph, Stephan Fahr, Mehdi Hedayati, Franz Faupel, Mady Elbahri et Carsten Rockstuhl. « Effective Optical Properties of Plasmonic Nanocomposites ». Materials 7, n^o 2 (27 janvier 2014) : 727–41. http://dx.doi.org/10.3390/ma7020727.

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Gan’shina, E., M. Kochneva, M. Vashuk, A. Vinogradov, A. Granovsky, V. Gushchin, P. Shcherbak, Chong-Oh Kim et Cheol Gi Kim. « Magneto-optical properties of magnetic nanocomposites ». Physics of Metals and Metallography 102, S1 (décembre 2006) : S32—S35. http://dx.doi.org/10.1134/s0031918x06140079.

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Bolesta, I., M. Vakiv, V. Haiduchok, O. Kushnir, A. Demchuk, S. Nastyshyn et R. Gamernyk. « Optical Properties of LiNbO3-Ag Nanocomposites ». Acta Physica Polonica A 133, n^o 4 (avril 2018) : 860–63. http://dx.doi.org/10.12693/aphyspola.133.860.

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Pattabi, Manjunatha, et Amma B. Saraswathi. « Optical Properties of CdS–PVA Nanocomposites ». Composite Interfaces 17, n^o 2-3 (janvier 2010) : 103–11. http://dx.doi.org/10.1163/092764410x490527.

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Kumbhakar, Pathik, Suprakas Sinha Ray et Andey L. Stepanov. « Optical Properties of Nanoparticles and Nanocomposites ». Journal of Nanomaterials 2014 (2014) : 1–2. http://dx.doi.org/10.1155/2014/181365.

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Quang Dat, Do, Lam Van Nang, Chu Manh Hung, Chu Thi Xuan, Nguyen Van Duy et Nguyen Duc Hoa. « Preparation and Gas Sensing Properties of rGO/CuO Nanocomposites ». ECS Journal of Solid State Science and Technology 11, n^o 3 (1 mars 2022) : 035009. http://dx.doi.org/10.1149/2162-8777/ac5c7f.

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Gas sensors are instrumental in the control and monitoring of air pollution. A facile fabrication method for low-cost gas sensors with high sensitivity and a fast response time is crucial in practical applications. Here, reduced graphene oxide (rGO)–CuO nanocomposites were synthesized for gas-sensing applications using a facile hydrothermal method. The crystal structure, surface morphology, and electrical properties of the nanocomposites were inferred from X-ray powder diffraction patterns, scanning electron microscopic images, and current–voltage (I–V) measurements, respectively. The results confirmed a high-quality rGO–CuO material with a spherical flower-like morphology. The CuO material showed a single-phase monoclinic crystal structure with an average crystal size of ∼21 nm. Within the composite, high-quality rGO was incorporated into the porous spherical flower-like CuO material. In gas-sensing measurements, the rGO–CuO nanocomposite detected NO2 gas at low concentrations (1–5 ppm) with reasonably high response values and a fast response time (<1 min). An rGO–CuO nanocomposite-based sensor was fabricated, showing good repeatability for practical applications.

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Zhai, Lindong, Hyun-Chan Kim, Ruth M. Muthoka, Muhammad Latif, Hussein Alrobei, Rizwan A. Malik et Jaehwan Kim. « Environment-Friendly Zinc Oxide Nanorods-Grown Cellulose Nanofiber Nanocomposite and Its Electromechanical and UV Sensing Behaviors ». Nanomaterials 11, n^o 6 (27 mai 2021) : 1419. http://dx.doi.org/10.3390/nano11061419.

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This paper reports a genuine environment-friendly hybrid nanocomposite made by growing zinc oxide (ZnO) nanorods on cellulose nanofiber (CNF) film. The nanocomposite preparation, characterizations, electromechanical property, and ultraviolet (UV) sensing performance are explained. CNF was extracted from the pulp by combining the 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO) oxidation and the aqueous counter collision (ACC) methods. The CNF film was fabricated using doctor blade casting, and ZnO nanorods were grown on the CNF film by seeding and by a hydrothermal method. Morphologies, optical transparency, mechanical and electromechanical properties, and UV sensing properties were examined. The nanocomposite’s optical transparency was more than 80%, and the piezoelectric charge constant d31 was 200 times larger than the CNF film. The UV sensing performance of the prepared ZnO-CNF nanocomposites was tested in terms of ZnO concentration, UV irradiance intensity, exposure side, and electrode materials. A large aspect ratio of ZnO nanorods and a work function gap between ZnO nanorods and the electrode material are essential for improving the UV sensing performance. However, these conditions should be compromised with transparency. The use of CNF for ZnO-cellulose hybrid nanocomposite is beneficial not only for electromechanical and UV sensing properties but also for high mechanical properties, renewability, biocompatibility, flexibility, non-toxicity, and transparency.

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Al Dream, Johara, Camila Zequine, K. Siam, Pawan K. Kahol, S. R. Mishra et Ram K. Gupta. « Electrochemical Properties of Graphene Oxide Nanoribbons/Polypyrrole Nanocomposites ». C 5, n^o 2 (12 avril 2019) : 18. http://dx.doi.org/10.3390/c5020018.

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Graphene is a highly studied material due to its unique electrical, optical, and mechanical properties. Graphene is widely applied in the field of energy such as in batteries, supercapacitors, and solar cells. The properties of graphene can be further improved by making nanocomposites with conducting polymers. In this work, graphene oxide nanoribbons (GONRs) were synthesized by unzipping multiwall carbon nanotubes. Graphene nanoribbons were used to make nanocomposites with polypyrrole for energy storage applications. The synthesized nanocomposites were structurally and electrochemically characterized to understand their structure and electrochemical properties. The electrochemical characterizations of these nanocomposites were carried out using cyclic voltammetry. The specific capacitance of the nanocomposites was observed to decrease with increasing scan rates. The highest specific capacitance of 2066 F/g was observed using cyclic voltammetry for the optimized nanocomposite of GONR and polypyrrole. Our study suggests that the electrochemical properties of graphene or polypyrrole can be improved by making their composites and that they could be successfully used as electrode materials for energy storage applications. This study can also be extended to the self-assembly of other conducting polymers and graphene nanoribbons through a simple route for various other applications.

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Ding, Haijuan, Yaping Fan, Hairong Dong, Chengtao Zhao et Debiao Zhao. « Progress of Laser Processing Technology in Ferroelectric Nanocomposites ». Advances in Materials Science and Engineering 2022 (11 octobre 2022) : 1–12. http://dx.doi.org/10.1155/2022/6502169.

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Although polymer-based nanocomposites have great application potential in many fields, compared with the application of ferroelectric nanocomposites in functional microscale structures and devices, especially in the field of photonics microdevices fabricated by laser processing, the development of polymer-based nanocomposites is relatively lagging behind. In this study, the polyvinylidene fluoride ferroelectric composite material was taken as the research object, and the preparation method of polymer nanocomposite material suitable for laser microstructure processing was solved by exploring the material functionalization method. The control of the optical properties of polyvinylidene fluoride ferroelectric composites was achieved through material design, control of the size of nanoparticles in the prepared polymer nanocomposites, and characterization of their structures and properties. Two-dimensional and three-dimensional structures of polymer nanocomposites were prepared by laser microstructure processing technology, and the optical properties of the microstructures were evaluated. When the applied stress field was zero, the macroscopic coercive field was larger, and the hystereswas loop was wider, while the butterfly curve changed rapidly near the coercive field, and the strain was negative. From the test results of the scanning electron microscope, it can be concluded that the lowest average power to find ablation traces was 0.06 mw, and the affected area was very small, and there was no damage to the surrounding nanotubes. Therefore, this paper believes that the damage threshold of carbon nanotubes was slightly less than 0.06 mw. This study contributes to the development of nanocomposite preparation methods for laser micromachining.

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Moklyak, Volodymyr, Volodymyr Chelyadyn, Andrii Hrubiak, Bogdan Ostafiychuk, Volodymyr Kotsyubynsky, Maryna Mizilevska, Mariya Moklyak, Roman Lisovskyy et Yurii Yavorskyi. « Synthesis, Structure, Optic and Photocatalytic Properties of Anatase/Brookite Nanocomposites ». Journal of Nano Research 64 (novembre 2020) : 39–48. http://dx.doi.org/10.4028/www.scientific.net/jnanor.64.39.

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Anatase/brookite nanocomposites were fabricated by the classical method of hydrolysis, additionally using hydrothermal treatment of preformed titanium dioxide sol with tetrabutyl orthotitanate. The influence of hydrothermal processing the buffer solution of TiO2 synthesis on the average particle sizes, specific surface area, pore sizes distributions, optical and photocatalytic properties investigated by X-ray diffraction, low-temperature nitrogen adsorption and UV-Vis spectroscopy. It has been determined that the hydrothermal treatment of pre-prepared titania sol as hydrolysis product leads to rutile formation after annealing at 400°C. Respective model of forming anatase/brookite/rutile nanocomposites was proposed. The changes of bang gap energy of TiO2 were observed and explained by effect of change phase composition and particles size of nanocomposite particles. Methylene blue (MB) photo-oxidation reactions using titanium dioxide nanocomposite were analyzed. Maximal photocatalytic activity of MB oxidation was detected for material with the ratio of the titania phases (anatase : brookite : rutile – 2 : 2 : 1). Synergistic effect between crystallinity, phase ratio, morphology of oxide material, band gap and photocatalytic activity in the anatase/brookite nanocomposites was established.

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ZAVYALOV, S. A., E. I. GRIGORIEV, A. S. ZAVYALOV, I. A. MISURKIN, S. V. TITOV, T. S. ZHURAVLEVA, I. V. KLIMENKO, A. N. PIVKINA, E. M. KELDER et J. SCHOONMAN. « STRUCTURE AND PROPERTIES OF TITANIUM–POLYMER THIN FILM NANOCOMPOSITES ». International Journal of Nanoscience 04, n^o 01 (février 2005) : 149–61. http://dx.doi.org/10.1142/s0219581x05003000.

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Thin film titanium/poly-para-xylylene nanocomposites with controlled Ti content are prepared by vacuum coevaporation and cocondensation of Ti and paracyclophane. The structure and chemical composition of as-deposited samples and the changes of electrical resistivity, which they undergo upon heating, are studied by atomic force microscopy, optical absorption spectroscopy, and the temperature coefficient of the electrical resistivity. It is shown that vacuum coevaporation results in the production of nanocomposite thin films with average Ti particle size of 10–50 nm. The inorganic phase is shown to be amorphous Ti for the samples with high metal content, whereas for the low-filled nanocomposites it consists of amorphous titanium oxide. Two types of kinetics of the nanocomposite oxidation process have been found and modeled by (i) inverse logarithmic and (ii) logarithmic functions depending on the metal content within the thin film. After a long preconditioning period in air the electrical conductivity of the thin film nanocomposites was carefully investigated by two-probe DC measurements. A strong correlation between the concentration of Ti in the thin films and the electrical conductivity dependency on temperature is found and modeled by a heterogeneous model of conductivity.

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Vanin, A. I., Yu A. Kumzerov, V. G. Solov’ev, S. D. Khanin, S. E. Gango, M. S. Ivanova, M. M. Prokhorenko, S. V. Trifonov, A. V. Cvetkov et M. V. Yanikov. « Electrical and Optical Properties of Nanocomposites Fabricated by the Introduction of Iodine in Porous Dielectric Matrices ». Glass Physics and Chemistry 47, n^o 3 (mai 2021) : 229–34. http://dx.doi.org/10.1134/s1087659621030123.

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Abstract The electrical and optical properties of nanocomposite materials fabricated by the dispersion of iodine in porous dielectric matrices of zeolites, zeolite-like aluminum phosphates, opals, asbestos, and porous aluminum oxide are studied. It is demonstrated that the physical properties of the produced nanocomposites depend significantly on the structure of a matrix.

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Gomez-Hermoso-de-Mendoza, Joseba, Junkal Gutierrez et Agnieszka Tercjak. « Optical Properties of Vanadium Oxide/Cellulose Triacetate Photochromic Films ». Proceedings 69, n^o 1 (3 novembre 2020) : 37. http://dx.doi.org/10.3390/cgpm2020-07182.

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The properties of polymer-based nanocomposites strongly depend on the fillers added and their dispersion on the matrix. Proposing a simple method that can control these variables is essential to obtain nanocomposites with enhanced properties. In this study, cellulose triacetate based nanocomposites modified with sol-gel synthesised vanadium oxide nanoparticles (V2O5) and poly(ethylene oxide-b-propylene oxide-b-ethylene oxide) (PEO-b-PPO-b-PEO or EPE) triblock copolymer were obtained by two methods: solvent casting (SC, drying at ambient conditions) and solvent vapour annealing (SVA, drying under solvent vapour atmosphere). Nanocomposites were characterised by Fourier-transform infrared spectroscopy (FTIR) and UV-vis spectroscopy. Nanocomposites presented green colour and high transparency, improving the SVA method the surface finish of the films. Moreover, V2O5 nanoparticles provided switchable photochromic properties, changing the film colour from green to pale blue when exposed to UV radiation. Nanocomposites with EPE triblock copolymer presented a more noticeable colour change. As for the speed of the recovery process to the initial state, it increased with the addition of EPE and the sol-gel content. Thus, it was proved that the SVA preparation method was more appropriate that the SC, as well as corroborate that the EPE triblock copolymer and the sol-gel content affected the properties of developed CTA nanocomposites.

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