scholarly journals Properties of Electrospun TiO2Nanofibers

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Bianca Caratão ◽  
Edgar Carneiro ◽  
Pedro Sá ◽  
Bernardo Almeida ◽  
Sandra Carvalho
Keyword(s):  
Thermal Analysis ◽  
Tissue Engineering ◽  
Differential Thermal Analysis ◽  
Composite Nanofibers ◽  
High Surface ◽  
High Surface Area ◽  
Optoelectronic Devices ◽  
Chemical Properties ◽  
Electrospinning Technique ◽  
And Chemical Properties

Titanium oxide filled polyvinylpyrrolidone (PVP) composite nanofibers have been prepared via a simple electrospinning technique. The combination of good TiO2properties with its high surface area leads these nanofibers into having a vast applicability such as cosmetics, scaffolds for tissue engineering, catalytic devices, sensors, solar cells, and optoelectronic devices. The structural and chemical properties of the prepared samples have been studied. The presence of the TiO2phase on the nanofibers was confirmed. An anatase to rutile transformation was observed at 600°C. Regarding the thermogravimetric and differential thermal analysis (TGA/DTA), the TIP decomposition and the PVP evaporation at 225°C were verified.

The Ceramist as Chemist - Opportunities for New Materials

1984 ◽  
Vol 32 ◽  
Author(s):  
D. R. Uhlmann ◽  
B.J.J. Zelinski ◽  
G.E. Wnek
Keyword(s):  
Wide Spectrum ◽  
High Surface ◽  
Sol Gel ◽  
High Surface Area ◽  
Glass Ceramics ◽  
Chemical Properties ◽  
Ceramic Materials ◽  
Process Technology ◽  
Chemical Homogeneity ◽  
And Chemical Properties

ABSTRACTThe use of sol-gel techniques to prepare glasses and crystalline ceramics offers outstanding opportunity for breakthroughs in technology. The areas of particular promise include novel glasses; crystallineceramics with exceptional microstructures; coatings for modification of electrical, optical, mechanical and chemical properties; porous media with high surface area and tailored chemistry; ceramic powders with high chemical homogeneity and narrow distributions of particle size; matrix materials in ceramicceramic composites; and a wide spectrum of specialty ceramic materials, ranging from abrasives and fibers to glass ceramics and films. Opportunities in each of these areas will be discussed and related to the advances in understanding and process technology required for their achievement. The theses will be advanced that creative chemistry provides the key to many of these advances, that ceramists simply MUST learn more chemistry, but that we dare not rest from our labors when the chemistry is done.

Functional sol-gel coated electrospun polyamide 6,6/ZnO composite nanofibers

2019 ◽  
Vol 39 (8) ◽  
pp. 752-761
Author(s):  
Ayse Celik Bedeloglu ◽  
Zeynep Islek Cin
Keyword(s):  
Zno Nanoparticles ◽  
Composite Nanofibers ◽  
High Surface ◽  
Sol Gel ◽  
High Surface Area ◽  
Dip Coating ◽  
Polymer Nanofibers ◽  
Electrospinning Technique ◽  
Medical Textiles ◽  
Nanofiber Mats

Abstract Polymer-based nanofibers are good candidates for medical textiles due to their excellent properties including high surface area, breathability and flexibility. Doping polymer nanofibers with different nanoparticles enhances their existing properties. In this study, electrospun polyamide 6,6 (PA6,6) composite nanofibers containing ZnO nanoparticles (<50 nm) in different amounts (1%, 3% and 5%) were first produced by electrospinning technique; then, these nanofibers were coated with sol-gel ZnO solution (0.5 m) via dip coating method at 1000, 3000 and 5000 μm/s speeds. The sol-gel coating process increased the breaking strength of nanofiber mats, while the incorporation of ZnO nanoparticles into the polymer nanofibers reduced. Compared to pure PA6,6 nanofiber mats, the ZnO sol-gel coated samples and doped nanofibers had lower reflectance values. In addition, the reflection values decreased as the additive and coating speed increased.

Effect of Pretreatment of Synthetic and Natural Carbons as Starting Materials for Carbon Nanotubes

2005 ◽  
Vol 23 ◽  
pp. 285-288 ◽  
Author(s):  
N. Buang ◽  
M. Aziz ◽  
S. Sanip ◽  
J.C. Tee ◽  
Z.H.Z Abidin ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Surface Area ◽  
Low Cost ◽  
High Surface ◽  
High Surface Area ◽  
Chemical Properties ◽  
Energy Storage And Conversion ◽  
Thermal Treatments ◽  
Active Materials ◽  
And Chemical Properties

Carbon are well known as active materials for energy storage and conversion. They are preferred because carbon materials have high electrical conductivity, low cost, high surface area, porosity, formability and possess good chemical and electrochemical resistivity. The most recently discovered novel carbon material is the carbon nanotubes, having unique geometrical structure and stable mechanical and chemical properties. The starting materials for carbon nanotubes production widely used are high purity graphite. Thus, two types of carbons were studied and thermal treatments were conducted at temperatures ranging from 600 – 800 °C for several hours. The effect of the pretreatment upon their morphology and surface area were looked into. It was found that significant changes occurred for the natural carbons while the synthetic carbons showed little or no changes at the particular temperature range. The thermal treatment has resulted in the exposure of fresh edge planes and microparticles as well as changes in the specific surface area and enhances their adsorption properties.

Development of Biodegradable Polyphosphazene- Nanohydroxyapatite Composite Nanofibers Via Electrospinning

2004 ◽  
Vol 845 ◽  
Author(s):  
Subhabrata Bhattacharyya ◽  
Lakshmi S. Nair ◽  
Anurima Singh ◽  
Nick R. Krogman ◽  
Jared Bender ◽  
...  
Keyword(s):  
Composite Nanofibers ◽  
Degradation Products ◽  
High Surface ◽  
High Surface Area ◽  
Chemical Properties ◽  
Dimethyl Formamide ◽  
Ambient Conditions ◽  
Transmission Electron ◽  
Physico Chemical ◽  
Wide Range

ABSTRACTBiodegradable polymeric nanofibers are of great interest as scaffolds for tissue engineering and drug delivery due to their extremely high surface area, high aspect ratio and similarity in structure to the extracellular matrix (ECM). Polyphosphazenes due to their synthetic flexibility, wide range of physico-chemical properties, non-toxic and neutral degradation products and excellent biocompatibility are suitable candidates for biomedical applications. The objective of the present study was to develop and evaluate composite nanofibers of a biodegradable polyphosphazene, poly[bis(ethyl alanato)phosphazene] (PNEA) and nanocrystals of hydroxyapatite (nHAp) via electrospinning. A suspension of nHAp in dimethyl formamide (DMF) sonicated with PNEA solution in tetrahydrofuran (THF) was used to develop composite nanofiber matrices via electrospinning at ambient conditions. In the present study the theoretical loading of nHAp was varied from 50%-90% (w/w) to PNEA. The nHAp content (actual loading of nHAp) of the composite nanofibers was determined by gravimetric estimation. The composite nanofibers were characterized by transmission electron microscopy (TEM), gravimetry and energy dispersive X-ray mapping. This study demonstrated the feasibility of developing novel composite nanofibers of biodegradable polyphosphazenes with more than 50% (w/w) loading of nHAp on and within the nanofibers.

A Systematic Study of the Catalytic Behavior at Enzyme–Metal-Oxide Nanointerfaces

Nano LIFE ◽  
2014 ◽  
Vol 04 (02) ◽  
pp. 1450005 ◽  
Author(s):  
Alan S. Campbell ◽  
Chenbo Dong ◽  
Andrew Maloney ◽  
Jeremy Hardinger ◽  
Xiao Hu ◽  
...  
Keyword(s):  
Metal Oxide ◽  
Mechanical Stability ◽  
Metal Oxide Nanoparticles ◽  
High Surface ◽  
High Surface Area ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Catalytic Behavior ◽  
Physical And Chemical ◽  
And Chemical Properties

Metal-oxide nanoparticles with high surface area, controllable functionality and thermal and mechanical stability provide high affinity for enzymes when the next generation of biosensor applications are being considered. We report on the synthesis of metal-oxide-based nanoparticles (with different physical and chemical properties) using hydrothermal processing, photo-deposition and silane functionalization. Physical and chemical properties of the user-synthesized nanoparticles were investigated using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and Raman scattering, respectively. Thus, characterized metal-oxide-based nanoparticles served as nanosupports for the immobilization of soybean peroxidase enzyme (a model enzyme) through physical binding. The enzyme–nanosupport interface was evaluated to assess the optimum nanosupport characteristics that preserve enzyme functionality and its catalytic behavior. Our results showed that both the nanosupport geometry and its charge influence the functionality and catalytic behavior of the bio-metal-oxide hybrid system.

In Situ microscopy of the anodic etching of silicon

1995 ◽  
Vol 53 ◽  
pp. 232-233
Author(s):  
Frances M. Ross ◽  
Peter C. Searson
Keyword(s):  
Composite Structures ◽  
High Surface ◽  
High Surface Area ◽  
Chemical Properties ◽  
Selective Etching ◽  
Silicon On Insulator ◽  
Second Phase ◽  
Porous Layers ◽  
New Class ◽  
Porous Semiconductors

Porous semiconductors represent a relatively new class of materials formed by the selective etching of a single or polycrystalline substrate. Although porous silicon has received considerable attention due to its novel optical properties1, porous layers can be formed in other semiconductors such as GaAs and GaP. These materials are characterised by very high surface area and by electrical, optical and chemical properties that may differ considerably from bulk. The properties depend on the pore morphology, which can be controlled by adjusting the processing conditions and the dopant concentration. A number of novel structures can be fabricated using selective etching. For example, self-supporting membranes can be made by growing pores through a wafer, films with modulated pore structure can be fabricated by varying the applied potential during growth, composite structures can be prepared by depositing a second phase into the pores and silicon-on-insulator structures can be formed by oxidising a buried porous layer. In all these applications the ability to grow nanostructures controllably is critical.

Recent trends in carbon nanotubes based prostate cancer therapy: A biomedical hybrid for diagnosis and treatment

2021 ◽  
Vol 18 ◽  
Author(s):  
Raja Murugesan ◽  
Sureshkumar Raman
Keyword(s):  
Prostate Cancer ◽  
Carbon Nanotubes ◽  
Drug Delivery ◽  
Drug Loading ◽  
High Surface ◽  
High Surface Area ◽  
High Capacity ◽  
Chemical Properties ◽  
Diagnosis And Treatment ◽  
High Level

: At present treatment methods for cancer are limited, partially due to the solubility, poor cellular distribution of drug molecules and, the incapability of drugs to annoy the cellular barriers. Carbon nanotubes (CNTs) generally have excellent physio-chemical properties, which include high-level penetration into the cell membrane, high surface area and high capacity of drug loading by in circulating modification with bio-molecules, project them as an appropriate candidate to diagnose and deliver drugs to prostate cancer (PCa). Additionally, the chemically modified CNTs which have excellent 'Biosensing' properties therefore makes it easy for detecting PCa without fluorescent agent and thus targets the particular site of PCa and also, Drug delivery can accomplish a high efficacy, enhanced permeability with less toxic effects. While CNTs have been mainly engaged in cancer treatment, a few studies are focussed on the diagnosis and treatment of PCa. Here, we detailly reviewed the current progress of the CNTs based diagnosis and targeted drug delivery system for managing and curing PCa.

Preparation of Glass-Ceramics Using Molybdenum Tailings

2011 ◽  
Vol 284-286 ◽  
pp. 1431-1434 ◽  
Author(s):  
Jin Rui Zhang ◽  
Ru Wang
Keyword(s):  
Heat Treatment ◽  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Crystalline Phase ◽  
Glass Ceramics ◽  
Chemical Properties ◽  
The Other ◽  
Raw Material ◽  
Physical Chemical ◽  
Nucleation Agents

In order to utilization the molybdenum tailings which be deposited in large quantities. Test used it to prepare glass-ceramics as main raw material, TiO2 as nucleation agents and CaO-Al2O3-SiO2 system and wollastonite as the principal crystalline phase. Heat treatment system of glass-ceramics was based on the differential thermal analysis. The crystalline phase, microstructure and characteristics of glass-ceramics were analysis by XRD, SEM and physical, chemical properties test. The result shows that the performance of glass-ceramics was superior to the other types of building decoration stone.

scholarly journals Atomically Dispersed M-N-C Catalysts in Proton Exchange Membrane Fuel Cells: Recent Progress and Perspectives

2021 ◽  
Vol 308 ◽  
pp. 01019
Author(s):  
Haoran Kong ◽  
Jiarong Liu ◽  
Yu Yue
Keyword(s):  
Fuel Cells ◽  
Cost Effectiveness ◽  
Proton Exchange Membrane ◽  
High Surface ◽  
High Surface Area ◽  
Chemical Properties ◽  
Proton Exchange ◽  
Synthesis Methods ◽  
Zeolitic Imidazolate Framework ◽  
Exchange Membrane

The selection of oxygen reduction reaction (ORR) catalysts plays a key role in enhancing the performance of proton exchange membrane fuel cells (PEMFCs). To optimize the energy conversion technology in PEMFCs and improve the cost-effectiveness of ORR catalysts, atomically dispersed metal-nitrogen-carbon (M-N-C) catalyst is regarded as one of the most promising materials to replace Pt-based catalysts. In this review, we summarize the advantages of atomically dispersed M-N-C catalysts in both physical and chemical properties, including controllable dimensions, ease of accessibility, high surface area and excellent conductivity. Additionally, the unique merits of their cost-effectiveness are also described by a concise comparison with other ORR catalysts. Subsequently, some of its main synthesis methods are based on the most commonly used zeolitic imidazolate framework (ZIF) precursor. Several other precursors involve carbon, nitrogen, and one or more active transition metals (mainly iron or cobalt) are introduced briefly. Although there are a variety of synthesis methods, all these methods are in line with pyrolysis technology. Then, the recent advancements of atomically dispersed M-N-C catalysts related to their development and application of Fe-N-C, Mn-N-C, and Co-N-C catalysts are comprehensively described. Finally, based on some common M-N-C catalysts, many improvement ideas are also proposed. The focus is on how to control the negative reaction in Fe-N-C catalysts, improve the activity of Co-N-C catalysts and Mn-N-C catalysts, and find more suitable transition metal materials to prepare M-N-C catalysts.

Nano Hydroxyapatite (Nano-Hap): A Potential Bioceramic For Biomedical Applications

2021 ◽  
Vol 06 ◽  
Author(s):  
Varun Saxena ◽  
Lalit Pandey ◽  
T. S. Srivatsan
Keyword(s):  
Tissue Engineering ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Biomedical Applications ◽  
High Surface ◽  
High Surface Area ◽  
Biological Properties ◽  
Engineering Applications ◽  
Biological Responses ◽  
Size And Morphology

Background: Hydroxyapatite (HAp) is one of the most studied biomimic for biomedical applications. Specially, nano-HAp has been utilized for bone tissue engineering various orthopedic applications. HAp possesses various suitable properties such as bioactivity, biodegradability and cell proliferation efficiency for bone tissue engineering applications. Yet, lacks in self-antibacterial activity, high surface area and target efficiency. Results: In this directioon, researchers have focused on exploring the required surface as well as the inherent properties of HAp at the nanoscale. These properties are largely dependent on the composition, size and morphology of the nano-HAp. Hence, nano-HAp has been found to be an excellent candidate with an attractive combination of properties for selection and use in biomedical applications, those required to enhanced biological responses. Further, depending on the type of application, these factors can be tuned to optimize the performance. Conclusion: In this review article, we focus on the chemical structure of HAp and the routes chosen and used for the synthesis of the nano-HAp. The role of various parameters in controlling synthesis at the nanoscale are presented and briefly discussed. In addition, we provide an overview of the various applications for the pristine and doped nano-HAp with recent examples in areas spanning the following: (i) bone tissue engineering applications, (ii) drug delivery applications, (iii) surface coatings, and (iv) scaffolds. The effect of chemical composition on the mechanical properties, surface properties and biological properties are also highlighted. Nano-HAp is found to be highly proficient for its biomedical applications, especially for bone tissue engineering applications. The nano-sized properties enhances the biological responses. The dopant ions that replaces the Ca ion into the hydroxyapatite (HAp) lattice plays a crucial role in its biomedical applications

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