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.

Structural and Optical Properties of InSnO3 Sol-Gel Coatings to Use in Windows Glass Buildings

2010 ◽  
Vol 168-170 ◽  
pp. 2348-2351
Author(s):  
Lazaro De Jesus Dominguez Gallegos ◽  
Angélica Silvestre López Rodríguez ◽  
Pio Sifuentes Gallardo ◽  
Miguel Angel Hernández Rivera ◽  
María Guadalupe Garnica Romo ◽  
...  
Keyword(s):  
Optical Properties ◽  
Indium Tin Oxide ◽  
Sol Gel ◽  
Visible Region ◽  
Optical Transmittance ◽  
Indium Chloride ◽  
Glass Substrates ◽  
Tin Chloride ◽  
Ito Thin Films ◽  
Ito Films

Indium stannate (InSnO3) films doping with small amounts of copper are made highly useful as architectural window coatings. Indium-tin-oxide (ITO) has attracted intense interest due to some of its unique characteristics; it has high optical transmittance in the visible region, low electric resistivity, and chemical stability. Therefore, ITO thin films have been found to play an important role in opto-electronic applications. In this work, uniform and transparent ITO films were deposited onto glass substrates using a sol-gel process. The initial sols were prepared by mixing solutions of indium chloride prepared in anhydrous ethanol with tin chloride and mechanically stirring and refluxed 2 hours and aged 2 week, the resultant mixture until a clear and sticky coating sol was obtained. The glass substrates were spin-coated and annealed at 500 °C. Because annealing conditions affect the microstructures, the properties of the resultant ITO films can be controlled. The optical transmittance of 200 nm thick ITO film was more than 80% in the visible region. The surface morphology examined by SEM appears to be uniform over large surface areas. The structural, microstructural and optical properties of the coatings and powders made from the sols were extensively characterized by using XRD, AFM and spectrophotometer techniques

Genesis and Growth of Nanoparticles during Sol-Gel Synthesis

2003 ◽  
Vol 788 ◽  
Author(s):  
Nan Yao ◽  
King Lun Yeung ◽  
Guoxing Xiong ◽  
Shishan Sheng
Keyword(s):  
Sol Gel ◽  
Nanometer Scale ◽  
In Situ Observation ◽  
Sol Gel Process ◽  
Silica Alumina ◽  
The Rich ◽  
Morphological Transformations ◽  
Sol Gel Synthesis ◽  
Gel Network

ABSTRACTIn situ observation of the genesis and growth of silica-alumina structures during the sol-gel process has been carried out. Although the gross structure of the gel network is kinetically stabilized, in situ AFM study reveals that at nanometer scale, the internal structure of the gel is dynamic as shown by the rich and complex morphological transformations.

scholarly journals Incorporation of Nanohybrid Films of Silica into Recycled Polystyrene Matrix

2015 ◽  
Vol 2015 ◽  
pp. 1-6
Author(s):  
Genoveva Hernández-Padrón ◽  
Domingo Rangel-Miranda ◽  
Gerardo Cedillo ◽  
Alejandra Blanco-Hernández
Keyword(s):  
Sol Gel ◽  
Textural Properties ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Glass Substrates ◽  
H Nmr ◽  
Sol Gel Process ◽  
Nmr Techniques ◽  
Polystyrene Waste ◽  
Sol Gel Synthesis

An alternative for the reutilization of polystyrene waste containers consisting in creating a hybrid material made of SiO2nanoparticles embedded in a matrix of recycled polystyrene (PSR) has been developed. Recycled polystyrene functionalized (PSRF) was used to influence the morphological and antifog properties by the sol-gel synthesis of nanohybrid silica. To this end, silica nanoparticles were produced from alkoxide precursors in the presence of recycled polystyrene. The functionalization of this polymeric matrix was with the purpose of uniting in situ carboxyl and silanol groups during the sol-gel process. In this way, opaque or transparent solid substrates can be obtained, with each of these endowed with optical conditions that depend on the amount of reactants employed to prepare each nanohybrid specimen. The nanohybrids were labelled as SiO2/PSR (HPSR) and SiO2/PSRF (HPSRF) and their properties were then compared to those of commercial polystyrene (PS). All the prepared samples were used for coating glass substrates. The hydrophobicity of the resultant coatings was determined through contact angle measurement. The nanohybrid materials were characterized by FT-IR and1H-NMR techniques. Additionally, TGA and SEM were employed to determine their thermal and textural properties.

Structural, Optical and Electrical Characterization of Mo Doped In2O3 Thin Films Prepared via Sol-Gel Spin Coating Technique

2012 ◽  
Vol 576 ◽  
pp. 607-610 ◽  
Author(s):  
Saeed Mohammadi ◽  
Hossein Abdizadeh ◽  
Mohammad Reza Golobostanfard
Keyword(s):  
Thin Films ◽  
Spin Coating ◽  
Sol Gel ◽  
Visible Region ◽  
Electrical Characterization ◽  
Optical Transmittance ◽  
Spin Coating Technique ◽  
Coating Technique ◽  
Glass Substrates ◽  
Average Optical Transmittance

The optically transparent conducting molybdenum doped indium oxide (IMO) thin films were deposited on glass substrates by sol-gel spin coating technique. The effect of various molybdenum contents in the range of 0.25–1 at.% on the structural, morphological, optical and electrical properties was studied. XRD results confirmed the formation of cubic bixbyite structure of In2O3 with preferred orientation along (222) plane. Microstructural studies show nearly spherical morphology for thin films with size in the range of 20-40 nm. The films doped with 0.25 at.% Mo found to exhibit a minimum electrical resistivity of 188×10-3 Ω.cm and an average optical transmittance of more than 80% in the visible region with a band gap of 3.85 eV.

Investigation of Aluminum Content on the Properties of Sol-Gel-Derived Zinc Oxide Thin Films

2007 ◽  
Vol 561-565 ◽  
pp. 1173-1176
Author(s):  
Shu Wen Xue ◽  
Xiao Tao Zu
Keyword(s):  
Sol Gel ◽  
Optical Transmittance ◽  
Atomic Ratio ◽  
Zno Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Al Content ◽  
Glass Substrates ◽  
Wide Range ◽  
Sol Gel Process

This paper reports that ZnO:Al films were deposited onto glass substrates by sol-gel process. Al/Zn atomic ratio varied in a wide range from 0 ~ 20%. The structural and optical properties were investigated by X-ray diffraction (XRD) and optical transmittance, respectively. X-ray photoemission spectroscopy (XPS) was used to investigate the elemental compositions. XRD results showed that ZnO films remained c-axis-orientated when Al/Zn atomic ratio was below 20% and the grain size decreased with increasing Al content. The optical transmittance showed that the optical bandgap of ZnO films blueshifted with increasing Al/Zn atomic ratio from 0-20%. XPS measurements showed that the binding energy of O1s increased with increasing Al content.

scholarly journals Template-Assisted Sol-Gel Synthesis of Nanocrystalline BaTiO3

2010 ◽  
Vol 7 (3) ◽  
pp. 894-898 ◽  
Author(s):  
T. V. Anuradha
Keyword(s):  
Reverse Micelles ◽  
Condensation Reaction ◽  
Sol Gel ◽  
Average Particle Size ◽  
Covalent Bond ◽  
Average Particle ◽  
Sol Gel Process ◽  
Nanoscale Structure ◽  
Sol Gel Synthesis ◽  
Controlled Hydrolysis

Nanocrystalline perovskite barium titanate with an average particle size less than ∼10 nm is produced using sol-gel route involving ligand-assisted templating. BaTiO3is obtained by the controlled hydrolysis and condensation reaction of barium acetate (Ba(CH3COO)2) with titanium tetra chloride (TiCl4) in the reverse micelles of dodecylamine (DDA) which is used as the template. Our attempts to produce mesoporous BaTiO3have resulted in the formation of nanocrystalline BaTiO3. The synthesis of nanostructured BaTiO3is carried out using the ligand-assisted templating approach which proceeds through the sol-gel route. Dodecylamine is used as the template. The sol-gel process in general presents inherent advantages because the nanostructure of the desired materials can be controlled together with their porous structure. Ligand-assisted templating approach involves the formation of covalent bond between the inorganic analogue and the template. Ba(CH3COO)2and TiCl4are used as barium-source and titanium-source respectively. The reaction between Ba(CH3COO)2and TiCl4is found to take place deliberately on the pre-assembled species which acts as the template or occurring with in them which in turn will lead to the generation of the desired nanoscale structure (nanopores or nanoparticles).

Surface Morphology and Optical Properties of ZnO Films Synthesis Using Different Solvent

2013 ◽  
Vol 832 ◽  
pp. 478-482 ◽  
Author(s):  
Sharul Ashikin Kamaruddin ◽  
Mohd Zainizan Sahdan ◽  
Kah Yoong Chan ◽  
Siti Nooraya Mohd Tawil ◽  
Nayan Nafarizal ◽  
...  
Keyword(s):  
Optical Properties ◽  
Surface Morphology ◽  
Ethylene Glycol ◽  
Sol Gel ◽  
Visible Region ◽  
Reaction Medium ◽  
Zno Films ◽  
Large Area ◽  
Vis Spectroscopy ◽  
Sol Gel Process

Zinc oxide (ZnO) is a promising electronic material for a variety of large area electronic applications including thin-film sensors, transistors, and solar cells. Various techniques have been focused and explored to synthesize ZnO films. In this study, sol-gel process was adopted as the fabrications process to grow the ZnO films. Three different types of solvents were used including ethanol, isopropanol and ethylene glycol as the reaction medium in the ZnO solution. The correlation between different solvents used and the properties of the ZnO films was explored and observed. The surface morphologies, structural and optical properties were examined using field émission scanning electron microscope (FESEM), X-ray diffractometer (XRD) and ultraviolet-visible (UV-Vis) spectroscopy. Through the observation from FESEM results, the surface morphology changed when different solvents were used. The crystallographic structures of the ZnO films demonstrate high crystallinity, and the extracted crystallite size is around 30 nm. Furthermore, ZnO films synthesized using isopropanol and ethylene glycol exhibit high transmittance spectra greater than 80% in the visible region. In general, the experimental results revealed that different solvents in the sol-gel process exert influences on the properties of the ZnO films.

The Preparation and Optical Property of ZnO Thin-Film by Electrospray

2009 ◽  
Vol 155 ◽  
pp. 151-154 ◽  
Author(s):  
Yan Huai Ding ◽  
Ping Zhang ◽  
Yong Jiang ◽  
Fu Xu ◽  
Jing Chen ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Property ◽  
Sol Gel ◽  
Visible Region ◽  
Optical Transmittance ◽  
Zno Thin Films ◽  
Zno Films ◽  
Ultraviolet Region ◽  
Force Microscopy ◽  
Glass Substrates

ZnO thin-films were prepared from sol-gel precursors using electrospray method. The structure, morphology and optical property of ZnO thin-films deposited on glass substrates were investigated by X-ray diffraction (XRD), atomic force microscopy (AFM) and absorption spectrums (ABS). The surface images obtained directly from AFM showed the compact ZnO films were composed of wurtzite ZnO nanoparticles. The ZnO films presented high optical transmittance in the visible region and strong absorption in ultraviolet region.

scholarly journals Nanostructured LiFe5O8 by a Biogenic Method for Applications from Electronics to Medicine

Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 193
Author(s):  
Silvia Soreto Teixeira ◽  
Manuel P. F. Graça ◽  
José Lucas ◽  
Manuel Almeida Valente ◽  
Paula I. P. Soares ◽  
...  
Keyword(s):  
Spinel Ferrite ◽  
Sol Gel ◽  
Reaction Medium ◽  
Magnetic Hyperthermia ◽  
Magnetic Characteristics ◽  
Secondary Phases ◽  
Heat Treated ◽  
Structure Morphology ◽  
Sol Gel Process ◽  
Crystallite Sizes

The physical properties of the cubic and ferrimagnetic spinel ferrite LiFe5O8 has made it an attractive material for electronic and medical applications. In this work, LiFe5O8 nanosized crystallites were synthesized by a novel and eco-friendly sol-gel process, by using powder coconut water as a mediated reaction medium. The dried powders were heat-treated (HT) at temperatures between 400 and 1000 °C, and their structure, morphology, electrical and magnetic characteristics, cytotoxicity, and magnetic hyperthermia assays were performed. The heat treatment of the LiFe5O8 powder tunes the crystallite sizes between 50 nm and 200 nm. When increasing the temperature of the HT, secondary phases start to form. The dielectric analysis revealed, at 300 K and 10 kHz, an increase of ε′ (≈10 up to ≈14) with a tanδ almost constant (≈0.3) with the increase of the HT temperature. The cytotoxicity results reveal, for concentrations below 2.5 mg/mL, that all samples have a non-cytotoxicity property. The sample heat-treated at 1000 °C, which revealed hysteresis and magnetic saturation of 73 emu g−1 at 300 K, showed a heating profile adequate for magnetic hyperthermia applications, showing the potential for biomedical applications.

Photocatalytic Degradation of Methylene Blue by NiO Thin Films under Solar Light Irradiation

2019 ◽  
Vol 56 ◽  
pp. 152-157 ◽  
Author(s):  
Abdelouahab Noua ◽  
Hichem Farh ◽  
Rebai Guemini ◽  
Oussama Zaoui ◽  
Tarek Diab Ounis ◽  
...  
Keyword(s):  
Thin Films ◽  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Sol Gel ◽  
Visible Region ◽  
Optical Transmittance ◽  
Dip Coating ◽  
Light Irradiation ◽  
Solar Light ◽  
Solar Light Irradiation

Nickel oxide (NiO) thin films were successfully deposited by sol-gel dip-coating method on glass substrates. The structural, morphological and optical properties in addition to the photocatalytic activity of the prepared films were investigated. The results show that the films have a polycrystalline NiO cubic structure with dense NiO grains and average optical transmittance in the visible region. The photocatalytic properties of the films were studied through the degradation of methylene blue and 89% of degradation was achieved for 4.5h of solar light irradiation exposure which indicates the capability of NiO photocatalytic activity.

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