We report the structural and optical properties of composite films formed from mixed suspensions of cellulose nanocrystals (CNCs) and fluorescent latex nanoparticles (NPs). We explored the effect of NP concentration, size, surface charge, glass transition temperature and film processing conditions on film structure and properties. The chiral nematic order, typical of CNC films, was preserved in films with up to 50 wt% of negatively-charged latex NPs. Composite films were characterized by macroscopically close-to-uniform fluorescence, birefringence, and circular dichroism properties. In contrast, addition of positively charged latex NPs led to gelation of CNC-latex suspensions and disruption of the chiral nematic order in the composite films. Large latex NPs disrupted the chiral nematic order to a larger extend than small NPs. Furthermore, the glass transition of latex NPs had a dramatic effect on the structure of CNC-latex films. Latex particles in the rubbery state were easily incorporated in the ordered CNC matrix and improved the structural integrity of its chiral nematic phase.
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http://dx.doi.org/10.1039/c5nr00660k | DOI Listing |
Pharmaceutics
December 2024
Vinča Institute of Nuclear Sciences, National Institute of the Republic of Serbia, University of Belgrade, Mike Petrovića Alasa 12-14, 11001 Belgrade, Serbia.
Pathogen bacteria appear and survive on various surfaces made of steel or glass. The existence of these bacteria in different forms causes significant problems in healthcare facilities and society. Therefore, the surface engineering of highly potent antimicrobial coatings is highly important in the 21st century, a period that began with a series of epidemics.
View Article and Find Full Text PDFPolymers (Basel)
December 2024
Graduate School of Advanced Science and Technology, Japan Advanced Institute of Science and Technology (JAIST), 1-1 Asahidai, Nomi 923-1292, Japan.
Polybenzimidazole (PBI) is a high-performance polymer known for its excellent thermal stability, mechanical strength, and chemical resistance, attributes that are derived from its unique structure comprising repeated benzene and imidazole rings. However, limitations such as relatively low thermal stability and moisture sensitivity restrict its application as a super engineering plastic. In this study, amide groups are incorporated into the PBI backbone to synthesize the copolymer poly(BI--A), effecting a structural modification at the molecular level.
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December 2024
Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory, 1, 119991 Moscow, Russia.
The scope of this work was to develop a thin-film composite (TFC) membrane for the separation of CO/CO mixtures, which are relevant for many processes of gas processing and gasification of carbon-based feedstock. Special attention was given to the development of highly permeable porous polysulfone (PSF) supports (more than 26,000 GPU for CO) since both the selective and support layers contribute significantly to the overall performance of the TFC membrane. The PSF porous support is widely used in commercial and lab-scale TFC membranes, and its porous structure and other exploitation parameters are set during the non-solvent-induced phase separation (NIPS) process.
View Article and Find Full Text PDFMicromachines (Basel)
December 2024
School of Integrated Circuit, Southeast University, Nanjing 210096, China.
Aluminum nitride (AlN) with a wide band gap (approximately 6.2 eV) has attractive characteristics, including high thermal conductivity, a high dielectric constant, and good insulating properties, which are suitable for the field of resistive random access memory. AlN thin films were deposited on ITO substrate using the radio-frequency magnetron sputtering technique.
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November 2024
Shenyang Academy of Instrumentation Science, Shenyang 110043, China.
Thermal treatment is a common method to improve the properties of optical thin films, but improper thermal treatment processing will result in the degradation of the optical properties of the optical thin film. The thermal stability of niobium oxide (NbO) thin films prepared by magnetron sputtering was systematically studied by analyzing the roughness and morphology of the film under different thermal treatment processes. The results show that the amorphous stability of the NbO thin film can be maintained up to 400 °C.
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