The Experts below are selected from a list of 4098 Experts worldwide ranked by ideXlab platform
Malcolm Polk - One of the best experts on this subject based on the ideXlab platform.
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GOAL/ABSTRACT M98-G8 MOLECULAR SPINNERETS FOR POLYMERIC FIBERS
2013Co-Authors: Karl I. Jacob, Malcolm PolkAbstract:The objective of this work is to investigate, design, and synthesize molecular spinning machines that can be shaped in the form of membranes which can control fiber structures and Produce Nanofibers. Using this design entire spinning units and associated systems, which currently occupy two or three floors, can be made to fit in a small room. Fibers with custom designed structures and properties can be spun with extreme precision and very fine fibers can be spun using this technique. The energy requirements will be diminished by an order of magnitude. The drawing process can be eliminated altogether. Start up and transition time for spinning different polymers will be reduced significantly thus reducing the waste. Eventually, polymerization and spinning can be combined into a single small unit. The development of this technology can revolutionize the fiber, textile, and apparel industry. Identification and development of unique discotic molecules is the key for constructing molecular spinnerets. Using synthetic and computational tools we are developing discotics and discotic membranes. We have synthesized a candidate discotic structure already, and we are using it to build a first generation molecular spinning machines (fi
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INVESTIGATORS: GOAL/ABSTRACT M98-G8 MOLECULAR SPINNERETS FOR POLYMERIC FIBERS
2013Co-Authors: Karl I. Jacob, Malcolm PolkAbstract:The objective of this work is to investigate, design, and synthesize molecular spinning machines that can be shaped in the form of membranes which can control fiber structures and Produce Nanofibers. Using this design entire spinning units and associated systems, which currently occupy two or three floors, can be made to fit in a small room. Fibers with custom designed structures and properties can be spun with extreme precision and very fine fibers can be spun using this technique. The energy requirements will be diminished by an order of magnitude. The drawing process can be eliminated altogether. Start up and transition time for spinning different polymers will be reduced significantly thus reducing the waste. Eventually, polymerization and spinning can be combined into a single small unit. The development of this technology can revolutionize the fiber, textile, and apparel industry. Identification and development of unique discotic molecules is the key for constructing molecular spinnerets. Using synthetic and computational tools we are developing discotics and discotic membranes. We have synthesized a candidate discotic structure already, and we are using it to build a first generation molecular spinning machines (fig 4)
Anil Gaikwad - One of the best experts on this subject based on the ideXlab platform.
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development of non woven Nanofibers of egg albumen poly vinyl alcohol blends influence of solution properties on morphology of Nanofibers
Polymer Journal, 2011Co-Authors: G V N Rathna, J P Jog, Anil GaikwadAbstract:Egg albumen (EA), a highly functional globular protein with desirable properties, is the least-explored material for biomaterial applications, although it is available in abundance. In our studies, we explored the viability of EA and various blends with biocompatible and non-toxic poly (vinyl alcohol) (PVA) to Produce Nanofibers for biomedical applications. EA and PVA blends were prepared in various compositions. Electrospinning was used to fabricate non-woven Nanofibers. Solution properties, such as viscosity and electrical conductivity, were evaluated for various prepared solutions. Solution viscosity increased with increasing polymer concentration. Solutions with higher contents of EA recorded increased conductivity, which decreased with increasing PVA content. The influence of solution properties on the morphological appearance of as-spun products was studied using scanning electron microscopy. Instead of Nanofibers, nanoparticles and microparticles of EA were Produced at even higher contents. In contrast, a gradual increase in the addition of PVA content to 8% EA solution resulted in the transformation of particles from large agglomerates to very fine fibers (≈100 nm in diameter) because of the influence of polymer content, viscosity and conductivity. The polymer–polymer interactions in the prepared materials have been validated by Fourier transform infrared spectroscopy, differential scanning calorimetry, X-ray diffraction and gel electrophoresis. In our studies, we explored the viability of egg albumen (EA) and its blend poly (vinyl alcohol) (PVA) to Produce Nanofibers for biomedical applications. EA and PVA blends were prepared in various compositions. Electrospinning was used for fabrication of non-woven Nanofibers. EA showed nanoparticles and microparticles instead of Nanofibers at even higher contents. In contrast, a gradual increase in the addition of PVA content to 8% EA solution resulted in the transformation of nanoparticles from large agglomerates to very fine fibers (≈100 nm).
Miqin Zhang - One of the best experts on this subject based on the ideXlab platform.
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centrifugal electrospinning of highly aligned polymer Nanofibers over a large area
Journal of Materials Chemistry, 2012Co-Authors: Dennis Edmondson, Ashleigh Cooper, Soumen Jana, David M Wood, Miqin ZhangAbstract:Well-ordered one-dimensional nanostructures are enabling important new applications in textiles, energy, environment and bioengineering owing to their unique and anisotropic properties. However, the production of highly aligned Nanofibers in a large area remains a significant challenge. Here we report a powerful, yet economical approach that integrates the concepts of the parallel-electrode electrospinning with centrifugal dispersion to Produce Nanofibers with a high degree of alignment and uniformity at a large scale. We first demonstrated this approach with polyvinylidene fluoride to show how experimental parameters regulate fiber properties, and then with chitosan, a natural polymer, and polyethylene oxide, a synthetic polymer, to illustrate the versatility of the system. As a model application, we then demonstrated the significance of fiber alignment in improving the piezoelectric effect for voltage generation. The technique presented here may be used for mass production of aligned Nanofibers of various polymers for a myriad of applications.
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electrospinning of chitosan derivative Nanofibers with structural stability in an aqueous environment
Physical Chemistry Chemical Physics, 2011Co-Authors: Ashleigh Cooper, Narayan Bhattarai, Forrest M Kievit, Michael Rossol, Miqin ZhangAbstract:We report a simple method to Produce stable chitosan derivative Nanofibers via electrospinning. A chitosan solution with lactate salt was electrospun to Produce Nanofibers, followed by thermal treatment to enhance fiber stability. Chemical and morphological analyses demonstrated that the resulting Nanofibers were crosslinked via amidation between chitosan and lactate salt. These fibers exhibited sustained morphological and structural stabilities to serve as a scaffold for biomedical applications.
Denni Kurniawan - One of the best experts on this subject based on the ideXlab platform.
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development of highly porous biodegradable γ fe2o3 polyvinyl alcohol nanofiber mats using electrospinning process for biomedical application
Materials Science and Engineering: C, 2017Co-Authors: Nor Hasrul Akhmal Ngadiman, Effaliza Misran, Ani Idris, Noordin Mohd Yusof, Denni KurniawanAbstract:The use of electrospinning process in fabricating tissue engineering scaffolds has received great attention in recent years due to its simplicity. The Nanofibers Produced via electrospinning possessed morphological characteristics similar to extracellular matrix of most tissue components. Porosity plays a vital role in developing tissue engineering scaffolds because it influences the biocompatibility performance of the scaffolds. In this study, maghemite (γ-Fe2O3) was mixed with polyvinyl alcohol (PVA) and subsequently electrospun to Produce Nanofibers. Five factors; nanoparticles content, voltage, flow rate, spinning distance, and rotating speed were varied to Produce the electrospun nanofibrous mats with high porosity value. Empirical model was developed using response surface methodology to analyze the effect of these factors to the porosity. The results revealed that the optimum porosity (90.85%) was obtained using 5% w/v nanoparticle content, 35 kV of voltage, 1.1 ml/h volume flow rate of solution, 8 cm spinning distance and 2455 rpm of rotating speed. The empirical model was verified successfully by performing confirmation experiments. The properties of optimum PVA/γ-Fe2O3 nanofiber mats such as fiber diameter, mechanical properties, and contact angle were investigated. In addition, cytocompatibility test, in vitro degradation rate, and MTT assay were also performed. Results revealed that high porosity biodegradable γ-Fe2O3/polyvinyl alcohol nanofiber mats have low mechanical properties but good degradation rates and cytocompatibility properties. Thus, they are suitable for low load bearing biomedical application or soft tissue engineering scaffold.
Masoumeh Valizadeh - One of the best experts on this subject based on the ideXlab platform.
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electrospinning of chitosan Nanofibers processing optimization
Carbohydrate Polymers, 2009Co-Authors: Homa Homayoni, Seyed Abdolkarim Hosseini Ravandi, Masoumeh ValizadehAbstract:Abstract In this study, the electrospinning of chitosan has been investigated. The problem of chitosan high viscosity, which limits its spinability, is resolved through the application of an alkali treatment which hydrolyzes chitosan chains and so decreases its their molecular weight. Solutions of the treated chitosan in aqueous 70–90% acetic acid Produce Nanofibers with appropriate quality and processing stability. Decreasing the acetic acid concentration in the solvent increases the mean diameter of the Nanofibers. Optimum Nanofibers are achieved with chitosan which is hydrolyzed for 48 h. Such Nanofibers result in a moisture regain which is 74% greater than that of treated and untreated chitosan powder. The diameter of this nanofiber, 140 nm, is strongly affected by the electrospinning conditions as well as by the concentration of the solvent. FTIR investigations prove that neither the alkali treatment nor the electrospinning process change the chemical nature of the polymer.