scholarly journals Synthesis of Silica Nanoparticles by Sol-Gel: Size-Dependent Properties, Surface Modification, and Applications in Silica-Polymer Nanocomposites—A Review

2012 ◽  
Vol 2012 ◽  
pp. 1-15 ◽  
Author(s):  
Ismail Ab Rahman ◽  
Vejayakumaran Padavettan
Keyword(s):  
Surface Modification ◽  
Silica Nanoparticles ◽  
Polymer Nanocomposites ◽  
Sol Gel ◽  
Chemical Properties ◽  
Size Dependent ◽  
Recent Developments ◽  
Gel Technique ◽  
Nanoparticles Characterization ◽  
Physical And Chemical

Application of silica nanoparticles as fillers in the preparation of nanocomposite of polymers has drawn much attention, due to the increased demand for new materials with improved thermal, mechanical, physical, and chemical properties. Recent developments in the synthesis of monodispersed, narrow-size distribution of nanoparticles by sol-gel method provide significant boost to development of silica-polymer nanocomposites. This paper is written by emphasizing on the synthesis of silica nanoparticles, characterization on size-dependent properties, and surface modification for the preparation of homogeneous nanocomposites, generally by sol-gel technique. The effect of nanosilica on the properties of various types of silica-polymer composites is also summarized.

Physico-Chemical Properties of Silica Coated Superparamagnetic Magnetite Nanoparticles Synthesized by Non-Seeded Process

2015 ◽  
Vol 1107 ◽  
pp. 267-271
Author(s):  
Sodipo Bashiru Kayode ◽  
Azlan Abdul Aziz
Keyword(s):  
Silica Nanoparticles ◽  
Magnetite Nanoparticles ◽  
Colloidal Suspension ◽  
Sol Gel ◽  
Chemical Properties ◽  
Colloidal Suspensions ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Physico Chemical ◽  
Physical And Chemical

The science of core-shell nanoparticles requires investigation into several physical and chemical properties of the composite nanoparticles. Unlike the conventional sol-gel or the reverse microemulsion micelle method, we presented here a non-seeded process of encapsulating superparamagnetic magnetite nanoparticles (SPMN) with silica. Physico-chemical analysis of the product was used to confirm the result of the coating procedure. Colloidal suspension of SPMN and silica nanoparticles were synthesised through coprecipitation method and modified Stöber method respectively. Afterwards, both colloidal suspensions of SPMN and silica nanoparticles were sonicated to encapsulate the SPMN with silica. Elemental mapping of the composite particles with electron spectroscopy imaging (ESI) confirmed the core-shell micrograph of the SPMN and silica. The X-ray diffraction pattern (XRD) showed the silica shell to be in amorphous form. FTIR analysis further confirmed the chemical properties of the product to be silica coated SPMN.

Hybrid Adhesives Filled with Functionalized and Non Functionalized Silica Nanoparticles

2018 ◽  
Vol 875 ◽  
pp. 9-13
Author(s):  
José de Jesús Figueroa-Lara ◽  
Miguel Torres-Rodríguez ◽  
Mirella Gutiérrez-Arzaluz
Keyword(s):  
Silica Nanoparticles ◽  
Sol Gel ◽  
Functionalized Silica ◽  
Adhesive Properties ◽  
Chemical Treatments ◽  
Strength Tests ◽  
Gel Technique ◽  
Physical And Chemical ◽  
Zirconia Nanoparticles

Hybrid adhesives epoxy-silica-zirconia were prepared and applied to bond aluminum sheet specimens. Silica nanoparticles were synthesized with the sol-gel “in situ” technique utilizing two different precursors, namely tetraethyl orthosilicate (TEOS) and 3 glycidyloxypropyltrimethoxysilane (GPTMS). Zirconia nanoparticles were prepared also with sol-gel technique and added to the hybrid adhesives before curing. The adhesive properties of the prepared materials were improved after performing several physical and chemical treatments to the aluminium specimens. The best apparent shear strength tests were for the adhesive hybrid materials prepared at 100°C with TEOS.

scholarly journals The Influence Of NO/O2 On The NOx Storage Properties Over A Pt-Ba-Ce/γ-Al2O3 Catalyst

2019 ◽  
Vol 17 (1) ◽  
pp. 1459-1465
Author(s):  
Xuedong Feng ◽  
Jing Yi ◽  
Peng Luo
Keyword(s):  
Sol Gel ◽  
Chemical Properties ◽  
No Oxidation ◽  
Test Results ◽  
X Ray Diffraction ◽  
Storage Performance ◽  
Transmission Electron ◽  
Temperature Programmed ◽  
Physical And Chemical ◽  
Al2o3 Catalyst

AbstractWith the purpose of studying the influence of NO/O2 on the NOx storage activity, a Pt-Ba-Ce/γ-Al2O3 catalyst was synthesized by an acid-aided sol-gel method. The physical and chemical properties of the catalyst were characterized by X-ray diffraction (XRD) and Transmission Electron Microscope (TEM) methods. The results showed that the composition of the catalyst was well-crystallized and the crystalline size of CeO2 (111) was about 5.7 nm. The mechanism of NO and NO2 storage and NOx temperature programmed desorption (NO-TPD) experiments were investigated to evaluate the NOx storage capacity of the catalyst. Pt-Ba-Ce/γ-Al2O3 catalyst presented the supreme NOx storage performance at 350℃, and the maximum value reached to 668.8 μmol / gcat. Compared with O2-free condition, NO oxidation to NO2 by O2 had a beneficial effect on the storage performance of NOx. NO-TPD test results showed that the NOx species stored on the catalyst surface still kept relatively stable even below 350℃.

Structuring-agent role in physical and chemical properties of Mo/SiO2 catalysts by sol-gel method

2018 ◽  
Vol 89 (2) ◽  
pp. 416-425
Author(s):  
William Giovanni Cortés-Ortiz ◽  
Alexander Baena-Novoa ◽  
Carlos Alberto Guerrero-Fajardo
Keyword(s):  
Sol Gel ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Gel Method ◽  
Sol Gel Method ◽  
Physical And Chemical ◽  
And Chemical Properties

scholarly journals Tribology of 2D Nanomaterials: A Review

2020 ◽  
Author(s):  
Paul С. Uzoma ◽  
Huan Hu ◽  
Mahdi Khadem ◽  
Oleksiy V. Penkov
Keyword(s):  
High Performance ◽  
2D Materials ◽  
Chemical Properties ◽  
Solid Lubricants ◽  
Friction Behavior ◽  
Comprehensive Overview ◽  
Wear Rates ◽  
Recent Developments ◽  
Frictional Coefficients ◽  
Physical And Chemical

The exfoliation of graphene has opened a new frontier in material science with a focus on 2D materials. The unique thermal, physical and chemical properties of these materials have made them one of the choicest candidates in novel mechanical and nano-electronic devices. Notably, 2D materials such as graphene, MoS2, WS2, h-BN, and Black Phosphorus have shown outstanding lowest frictional coefficients and wear rates, making them attractive materials for high-performance nano-lubricants and lubricating applications. The objective of this work is to provide a comprehensive overview of the most recent developments in the tribological potentials of 2D materials. At first, the essential physical, wear, and frictional characteristics of the 2D materials including their production techniques are discussed. Subsequently, the experimental explorations and theoretical simulations of the most common 2D materials are reviewed in regards to their tribological applications such as their use as solid lubricants and surface lubricant nano-additives. The effects of micro/nano textures on friction behavior are also reviewed. Finally, the current challenges in tribological applications of 2D materials and their prospects are discussed.

scholarly journals Amine-Functionalized Mesoporous Silica Nanoparticles: A New Nanoantibiotic for Bone Infection Treatment

2017 ◽  
Vol 3 (1) ◽  
Author(s):  
Daniel Pedraza ◽  
Jaime Díez ◽  
Isabel Izquierdo-Barba ◽  
Montserrat Colilla ◽  
María Vallet-Regí
Keyword(s):  
Mesoporous Silica ◽  
Silica Nanoparticles ◽  
Mesoporous Silica Nanoparticles ◽  
Chemical Properties ◽  
Bone Infection ◽  
Bacterial Biofilm ◽  
Functionalized Mesoporous Silica ◽  
Transmission Electron ◽  
Infection Treatment ◽  
Physical And Chemical

AbstractThis manuscript reports an effective new alternative for the management of bone infection by the development of an antibiotic nanocarrier able to penetrate bacterial biofilm, thus enhancing antimicrobial effectiveness. This nanosystem, also denoted as “nanoantibiotic”, consists in mesoporous silica nanoparticles (MSNs) loaded with an antimicrobial agent (levofloxacin, LEVO) and externally functionalized with N-(2-aminoethyl)-3-aminopropyltrimethoxysilane (DAMO) as targeting agent. This amine functionalization provides MSNs of positive charges, which improves the affinity towards the negatively charged bacteria wall and biofilm. Physical and chemical properties of the nanoantibiotic were studied using different characterization techniques, including Xray diffraction (XRD), transmission electron microscopy (TEM), N

Properties of Nano-Hybrid Sol-Gel Materials Synthesized from Colloidal Silica-Silane Containing Epoxy Silane

2007 ◽  
Vol 336-338 ◽  
pp. 2278-2281 ◽  
Author(s):  
Moon Kyong Na ◽  
Dong Pil Kang ◽  
Hoy Yul Park ◽  
Myeong Sang Ahn ◽  
In Hye Myung
Keyword(s):  
Contact Angle ◽  
Colloidal Silica ◽  
Flat Surface ◽  
Coating Layer ◽  
Sol Gel ◽  
Chemical Properties ◽  
Coating Films ◽  
Initial Stage ◽  
Physical And Chemical ◽  
And Chemical Properties

Three kinds of colloidal silica (CS)/silane sol solutions were synthesized in variation with parameters such as different acidity and reaction time. Sol solutions were prepared from HSA CS/ methyltrimethoxysilane (MTMS), LS CS/MTMS and LS CS/MTMS/γ -Glycidoxypropyltri methoxysilane (ES) solutions. In order to understand their physical and chemical properties, sol-gel coating films were fabricated on glass. Coating films on glass, obtained from LS/MTMS sol, had high contact angle, also, much enhanced flat surface in the case of LS/MTMS sol was observed in comparison with HSA/ MTMS sol. From all sol-gel solutions, seasoning effect of for enhancing properties of sol-gel coating layer on glass was observed while such sol-gel solutions were left for 7days. In initial stage of sol-gel reaction, all most of sol solutions used in this work seem to be unstable, formation of coating films was a little hazy and rough. However, improved coating films as observed in 4days later. LS/MTMS/ES sol solutions were synthesized with ES, adding to LS/MTMS sol. Contact angle of LS/MTMS/ES sol-gel coating films decreased, since ES played a role in forming hydrophilic hydroxyl sol. The elastic portion of coating films prepared from LS/MTMS/ES sol increased with addition of ES, but thermal stability decreased a little.

Recent developments in the utility of saturated azaheterocycles in peptidomimetics

2022 ◽  
Author(s):  
Manish Kumar Singh ◽  
Mahesh K Lakshman
Keyword(s):  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Recent Developments ◽  
Physical And Chemical ◽  
And Chemical Properties

To large extent, the physical and chemical properties of peptidomimetic molecules are dictated by the integrated heterocyclic scaffolds they contain. Heterocyclic moieties are introduced into a majority of peptide-mimicking molecules...

Characteristics of Chitosan Nanoparticles for Water and Wastewater Treatment

2017 ◽  
pp. 223-261 ◽  
Author(s):  
Cayla Cook ◽  
Veera Gnaneswar Gude
Keyword(s):  
Wastewater Treatment ◽  
Chitosan Nanoparticles ◽  
Antimicrobial Properties ◽  
Chemical Properties ◽  
Water And Wastewater Treatment ◽  
Coagulation And Flocculation ◽  
Recent Developments ◽  
Water And Wastewater ◽  
Physical And Chemical

Chitosan is a naturally occurring biopolymer originating from several microbial species as well as crustacean species, such as shrimp and lobster. Chitosan has excellent physical and chemical properties that allow its use in various environmental applications especially in water treatment. It is a biodegradable polymer, and it is inexpensive providing an environmentally friendly and economic option for water and wastewater treatment. Chitosan offers a myriad of applications through chemical coagulation and flocculation, antimicrobial properties, adsorption capabilities, and nanofiltration and can provide a sustainable route for water and wastewater treatment. This book chapter elaborates the recent developments in chitosan applications in water and wastewater treatment.

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