High performance hierarchical nanoporous antireflective films by a facile sol–gel process

RSC Advances ◽  
2016 ◽  
Vol 6 (115) ◽  
pp. 113911-113918 ◽  
Author(s):  
Yao Xiao ◽  
Ronghua Ma ◽  
Changjian Wang ◽  
Xinkai Chen ◽  
Xvsheng Qiao ◽  
...  
Keyword(s):  
High Performance ◽  
Sol Gel ◽  
Single Layer ◽  
Hollow Silica ◽  
Glass Substrates ◽  
Sol Gel Process ◽  
Antireflective Films ◽  
Sol Gel Films

Single layer antireflection (SLAR) sol–gel films on super white glass substrates were prepared by hierarchically introducing hollow silica nano-spheres (HSNs) and F127 templated nano-pores.

Expansion of Nanosized MgSiO3/Chitosan Nanocomposite Structural and Spectroscopic for Loading Velosef by Nanomaterial Intervention

2021 ◽  
Author(s):  
amal aboelnaga ◽  
talaat Meaz ◽  
amany M elnahrawy
Keyword(s):  
Antimicrobial Activity ◽  
High Performance ◽  
Sol Gel ◽  
Polymerization Process ◽  
Absorption Bands ◽  
Structural Morphology ◽  
Crystallinity Degree ◽  
Chitosan Matrix ◽  
Antimicrobial Studies ◽  
Sol Gel Process

Abstract The aim of this study is to investigate the effect of different doses of Velosef in magnesium silica/chitosan nanocomposite in terms of structural, morphology, optical properties, and bioactivity. Loading Velosef in fine-sized magnesium silica/chitosan is an efficient engineering approach for drug delivery. The sol-gel process was used to prepare magnesium silica fine-sized before being blended into chitosan matrix, which acts as a potential morphogenetic biomaterial. The Velosef/magnesium silica/chitosan nanocomposites were characterized by XRD, TEM, SEM, FTIR, UV-absorption, and antimicrobial studies. The XRD was characteristic of the crystallinity degree of the MgO-SiO2/chitosan/Velosef nanocomposites with three maximum peaks at 26.37°, 33.34o, 36.9°. FTIR results indicated the structural change occurred with the Velosef sol-gel polymerization process. UV-absorbance reveals that the MgO-SiO2/chitosan nanocomposite appeared a high performance for loading Velosef at two absorption bands at 253 and 347 nm. The MgO-SiO2/Chitosan/Velosef nanocomposites showed considerable antimicrobial activity in opposition to the tested representative microorganisms. The maximum antimicrobial activity was obtained with MgO-SiO2/Chitosan against both Escherichia coli and Candida albicans (37 mm), while the minimum antimicrobial activity (30 mm) was recorded against B. mycoides and E. coli with control.

scholarly journals Immobilized Whole-Cell Transaminase Biocatalysts for Continuous-Flow Kinetic Resolution of Amines

Catalysts ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 438 ◽  
Author(s):  
Zsófia Molnár ◽  
Emese Farkas ◽  
Ágnes Lakó ◽  
Balázs Erdélyi ◽  
Wolfgang Kroutil ◽  
...  
Keyword(s):  
Continuous Flow ◽  
Kinetic Resolution ◽  
Sol Gel ◽  
Chiral Amines ◽  
Flow Mode ◽  
Immobilized Cell ◽  
Hollow Silica ◽  
E Coli ◽  
Sol Gel Process ◽  
Racemic Amines

Immobilization of transaminases creates promising biocatalysts for production of chiral amines in batch or continuous-flow mode reactions. E. coli cells containing overexpressed transaminases of various selectivities and hollow silica microspheres as supporting agent were immobilized by an improved sol-gel process to produce immobilized transaminase biocatalysts with suitable stability and mechanical properties for continuous-flow applications. The immobilized cell-based transaminase biocatalyst proved to be durable and easy-to-use in kinetic resolution of four racemic amines 1a–d. The batch and continuous-flow mode kinetic resolutions with transaminase biocatalyst of opposite stereopreference provided access to both enantiomers of the corresponding amines. By using the most suitable immobilized transaminase biocatalysts, this study describes the first transaminase-based approach for the production of both pure enantiomers of 1-(3,4-dimethoxyphenyl)ethan-1-amine 1d.

Preparation of SiO2 Antireflective Film by a Base/Acid Two-Step Catalyzed Sol-Gel Process

2013 ◽  
Vol 860-863 ◽  
pp. 845-848 ◽  
Author(s):  
De Yi Li ◽  
Kun Peng ◽  
Ling Ping Zhou ◽  
Jia Jun Zhu
Keyword(s):  
Raw Materials ◽  
Salt Spray ◽  
Sol Gel ◽  
Acid Base ◽  
Gel Method ◽  
Antireflective Film ◽  
Sol Gel Process ◽  
Acid Catalyzed ◽  
Antireflective Films ◽  
Silica Sols

SiO2 antireflective films were prepared by two-step catalyzed sol-gel method with TEOS as the raw materials, acid and ammonia as catalyst. Effects of the ratio of acid-catalyzed and base-catalyzed silica sols on the transmittance and stability of SiO2 film were investigated. The transmittance can be adjusted by change the ratio of base-catalyzed sols, and a higher transmittance can be obtained in the higher ratio of base-catalyzed coatings. A higher stability of SiO2 film in salt spray can be obtained in higher ratio of acid-catalyzed AR coatings. AR coatings with excellent transmittance and stability can be obtained by adjusting the ratio of acid/base catalyzed silica sols.

Transparent semiconductor zinc oxide thin films deposited on glass substrates by sol–gel process

2010 ◽  
Vol 36 (6) ◽  
pp. 1791-1795 ◽  
Author(s):  
Chien-Yie Tsay ◽  
Kai-Shiung Fan ◽  
Yu-Wu Wang ◽  
Chi-Jung Chang ◽  
Yung-Kuan Tseng ◽  
...  
Keyword(s):  
Thin Films ◽  
Zinc Oxide ◽  
Sol Gel ◽  
Oxide Thin Films ◽  
Glass Substrates ◽  
Sol Gel Process ◽  
Transparent Semiconductor

Relaxor Behavior in Ba0.8Sr0.2TiO3/ZrO2 Heterostructured Thin Films

2012 ◽  
Vol 1454 ◽  
pp. 89-96 ◽  
Author(s):  
Santosh K. Sahoo ◽  
H. Bakhru ◽  
Sumit Kumar ◽  
D. Misra ◽  
Y. N. Mohapatra ◽  
...  
Keyword(s):  
Thin Films ◽  
Activation Energy ◽  
Oxygen Vacancies ◽  
Sol Gel ◽  
Single Layer ◽  
Relaxor Behavior ◽  
Bst Thin Films ◽  
Si Substrates ◽  
Sol Gel Process ◽  
Loss Maximum

ABSTRACTBa0.8Sr0.2TiO3 (BST) thin films and Ba0.8Sr0.2TiO3/ZrO2 heterostructured thin films have been successfully fabricated on Pt/Ti/SiO2/Si substrates by a sol-gel process. The dielectric properties of these films were measured as a function of temperature in the frequency range of 1 kHz to 1 MHz. It is clearly observed that the dielectric peaks exist and shift to high temperature with the increase of frequency indicating the presence of relaxor-type behavior in the films. Also it is seen that one dielectric peak is observed in single layer BST thin films whereas two dielectric peaks are observed in BST/ZrO2 heterostructured thin films due to the presence of two dielectric layers having different band gap energies. The variation of peak temperature Tm, corresponding to dielectric loss maximum, with frequency and fitting to Arrhenius law gives activation energy of 1.24 eV which is very close to the activation energy of oxygen vacancies in BaTiO3. Hence, oxygen vacancies are the active defects which are contributing to the relaxation process in these films.

Sol-gel synthesis of biocompatible silica-chitosan hybrids and hydrophobic coatings

2008 ◽  
Vol 23 (8) ◽  
pp. 2053-2060 ◽  
Author(s):  
S. Smitha ◽  
P. Shajesh ◽  
P. Mukundan ◽  
K.G.K. Warrier
Keyword(s):  
Condensation Reaction ◽  
Sol Gel ◽  
Visible Region ◽  
Reaction Medium ◽  
Optical Transmittance ◽  
Hydrophobic Coatings ◽  
Glass Substrates ◽  
Sol Gel Process ◽  
Sol Gel Synthesis

A new organic–inorganic hybrid synthesized through a sol-gel process starting from alkoxysilane and chitosan is reported. Functionalization of the hybrid was effected through in situ hydrolysis–condensation reaction of methyltrimethoxysilane (MTMS) and vinyltrimethoxysilane (VTMS) in the reaction medium. The process yields highly transparent and hydrophobic silica–chitosan hybrids. The hybrid gel was investigated with respect to chemical modification, thermal degradation, hydrophobicity, and transparency under the ultraviolet-visible region. The extent of hydrophobicity had been tailored by varying the precursor ratio. SiO2–chitosan–MTMS hybrids showed a higher thermal stability than SiO2–chitosan–VTMS (SCV) hybrids with respect to hydrophobicity. Condensation of silsesquioxanes generated from the hydrolysis of MTMS and VTMS over the silica-chitosan particles impart hydrophobicity to the hybrid. The coatings of functionalized SiO2–chitosan precursor sol on glass substrates showed nearly 100% optical transmittance in the visible region. The present hybrid material may find application in optics and other industries.

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