Copyright (c) 2009 All rights reserved. http://works.bepress.com/ji_huan_he Recent documents in Ji-Huan He en-us Sat, 01 Aug 2009 14:53:49 PDT 3600 http://works.bepress.com/ji_huan_he/48 http://works.bepress.com/ji_huan_he/48 Fri, 31 Jul 2009 04:48:16 PDT This Update covers all aspects of electrospinning as used to produce Nanofibres. It contains an array of colour diagrams, mathematical models, equations and detailed references. It will be invaluable to anyone who is interested in using this technique and also to those interested in finding out more about the subject. Electrospinning is the cheapest and the most straightforward way to produce nanomaterials. Electrospun Nanofibres are very important for the scientific and economic revival of developing countries. Electrospinning was developed from electrostatic spraying and now represents an attractive approach for polymer biomaterials processing, with the opportunity for control over morphology, porosity and composition using simple equipment. Because electrospinning is one of the few techniques to prepare long fibres of nano- to micrometre diameter, great progress has been made in recent years. It is now possible to produce a low-cost, high-value, high-strength fibre from a biodegradable and renewable waste product for easing environmental concerns. For example, electrospun nanofibres can be used in wound dressings, filtration applications, bone tissue engineering, catalyst supports, non-woven fabrics, reinforced fibres, support for enzymes, drug delivery systems, fuel cells, conducting polymers and composites, photonics, medicine, pharmacy, fibre mats serving as reinforcing component in composite systems, and fibre templates for the preparation of functional nanotubes. If you have an ongoing interest in this area then why not consider also purchasing the Electrospinning and Nanofibres Bulletin? This current awareness service from the Polymer Library provides you with regular updates containing abstracts of new research from journals, conference proceedings, books and reports. It lets you know about all of the latest developments on both Electrospinning and Nanofibres, so you don't have to waste time, effort and money finding it all yourself. Combined with the 'Electrospun Nanofibres and Their Applications' Update, you'll have the complete package to introduce you to the topic, then keep you up-to-date with new developments. Add both products to your cart and you will save £100! Table of Contents 1. Introduction 1.1 What is nanotechnology 1.2 What is electrospinning 1.3 What affects electrospinning 1.4 Applications 1.5 Global Interest in the field of Electrospinning 2. Mathematical Models for Electrospinning Process 2.1 One-dimensional Model 2.2 Spivak-Dzenis model 2.3 Wan-Guo-Pan Model 2.4 Modified One-Dimensional Model 2.5 Modified Conservation of Charge 2.6 Renekers model 2.7 E-Infinity theory 3. Allometric Scaling in Electrospinning 3.1 Allometric Scaling in Nature 3.2 Allometrical Scaling Laws in Electrospinning 3.2.1 Relationship between radius r of jet and the axial distance z 3.2.2 Allometric scaling relationship between current and voltage 3.2.3 Allometric scaling relation between solution flow rate and current 3.2.4 Effect of concentration on electrospun polyacrylonitrile (PAN) nanofibres 3.2.5 Allometric Scaling Law between Average Polymer Molecular Weight and Electrospun Nanofibre Diameter 3.2.6 Effect of voltage on morphology and diameter of electrospun nanofibres 3.2.7 Enlarging Electrospinability by Nonionic Surfactants 3.3 Allometric Scaling Law for Static Fiction of Fibrous Materials 3.4 Allometric scaling in Biology 4. Application of Vibration Technology to Electrospinning 4.1 Effect of viscosity on diameter of electrospun fibre 4.2 Effect of Vibration on Viscosity 4.3 Application of vibration technology to polymer electrospinning 4.4 Effect of solution viscosity on mechanical characters of Electrospun Fibres 4.5 Carbon Nanotube Reinforced Polyacrylonitrile Nanofibres by Vibration-Electrospinning 5. Megnetio-electrospinning: Control of the instability 5.1 Critical Length of Straight Jet in Electrospinning 5.2 Controlling Stability by Magnetic Field 5.3 Controlling Stability by Temperature 5.4 Siro-electrospinning 6. BioMimic Fabrication of Electrospun Nanofibres with High-throughput 6.1 Spider-spinning 6.2 Electrospinning of silk fibroin nanofibres 6.3 Mystery in spider-spinning process 6.4 Bubble-electrospinning 7. Controlling Numbers and Sizes of Beads in Electrospun nanofibres 7.1 Experiment Observation 7.2 Effects of different solvents 7.3 Effect of the polymer concentration 7.4 Effect of salt additive 8. Electrospun Nanoporous Microspheres for Nanotechnology 8.1 Electrospun nanoporous spheres with Chinese drug 8.2 Electrospinning-dilation 8.3 Single Nanoporous Fibre by Electrospinning 8.4 Micro sphere with nano-porosity 8.5 Micro-composite fibres by electrospinning 9. Super-carbon Nanotubes: An E-infinity Approach 9.1 E-infinity Nanotechnology 9.2 Application of E-Infinity to Electrospinning 9.3 Super-carbon Nanotubes: An E-infinity Approach 10. Mechanics in Nano-textile Science 10.1 Jet-vortex spinning and Cyclone model 10.2 Two-phase flow of Yarn Motion in High Speed Air and Micropolar Model 10.3 Mathematical Model for Yarn motion in Tube 10.4 Nano-hydrodynamics 10.5 A New Resistance Formulation for Carbon Nanotubes and Nerve Fibres 10.6 Differential-difference Model for Nanotechnology 11. Nonlinear Dynamics in Sirofil/Sirospun Yarn Spinning 11.1 Convergent point 11.2 Linear Dynamical Model 11.3 Nonlinear Dynamical Model 11.4 Stable Working Condition for Three-strand Yarn Spinning 11.5 Nano-sirospinning Ji-Huan He monograph http://works.bepress.com/ji_huan_he/47 http://works.bepress.com/ji_huan_he/47 Fri, 31 Jul 2009 04:38:02 PDT Article Outline Glossary Definition of the Subject Introduction Solitons Compactons Generalized Solitons and Compacton-like Solutions Future Directions Cross References Bibliography Glossary Soliton A soliton is a stable pulse-like wave that can exist in some nonlinear systems. The soliton, after a collision with another soliton, eventually emerges unscathed. Compacton A compacton is a special solitary traveling wave that, unlike a soliton, does not have exponential tails. Generalized soliton A generalized soliton is a soliton with some free parameters. Generally a generalized soliton can be expressed by exponential functions. 8458 S Solitons and Compactons Compacton-like solution A compcton-like solution is a special wave solution which can be expressed by the squares of sinusoidal or cosinoidal functions. Definition of the Subject Soliton and compacton are two kinds of nonlinear waves. They play an indispensable and vital role in all ramifications of science and technology, and are used as constructive elements to formulate the complex dynamical behavior of wave systems throughout science: from hydrodynamics to nonlinear optics, from plasmas to shock waves, from tornados to theGreat Red Spot of Jupiter, from traffic flow to Internet, from Tsunamis to turbulence. More recently, soliton and compacton are of key importance in the quantum fields and nanotechnology especially in nanohydrodynamics. Ji-Huan He Encyclopedia http://works.bepress.com/ji_huan_he/46 http://works.bepress.com/ji_huan_he/46 Fri, 31 Jul 2009 04:29:26 PDT Glossary Soliton A soliton is a nonlinear pulse-like wave that can exist in some nonlinear systems. The isolated wave can propagate without dispersing its energy over a large region of space; collision of two solitons leads to unchanged forms, solitons also exhibit particlelike properties. Soliton perturbation theory The soliton perturbation theory is used to study the solitons that are governed by the various nonlinear equations in presence of the perturbation terms. Homotopy perturbation method The homotopy perturbationmethod is a useful tool to the search for solitons without the requirement of presence of small perturbations. In this method, a homotopy is constructed with a homotopy parameter, p. When p D 0, it becomes a nonlinear wave equation such as a KdV equation with a known soliton solution; when p D 1, it turns out to be the original nonlinear equation. To change p from zero to unity, one must only change from a trial soliton to the solved soliton. Variational iteration method The variational iteration method is a new method for obtaining soliton-type solutions of various nonlinear wave equations. The method begins with a soliton-type solution with some unknown parameters which can be determined after few iterations. The iteration formulation is constructed by a general Lagrange multiplier which can be identified optimally via variational theory. Exp-function method The exp-function method is a new method for searching for both soliton-type solutions and periodic solutions of nonlinear systems. The method assumes that the solutions can be expressed in arbitrary forms of the exp-function. Definition of the Subject The soliton is a kind of nonlinear wave. There are many equations ofmathematical physics which have solutions of the soliton type. The first observation of this kind of wave was made in 1834 by John Scott Russell [1]. In 1895, the famous KdV equation, which possesses soliton solutions, was obtained by D. J. Korteweg and H. de Vries [2], who established a mathematical basis for the study of various solitary phenomena. From a modern perspective, the soliton is used as a constructive element to formulate the complex dynamical behavior of wave systems throughout science: from hydrodynamics to nonlinear optics, from plasmas to shock waves, from tornados to the Great Red Spot of Jupiter, from traffic flow to the Internet, from Tsunamis to turbulence [3]. More recently, solitary waves are of key importance in the quantum fields: on extremely small scales and at very high observational resolution equivalent to a very high energy, space-time resembles a stormy ocean and particles and their interactions have soliton-type solutions [4]. Ji-Huan He Encyclopedia http://works.bepress.com/ji_huan_he/45 http://works.bepress.com/ji_huan_he/45 Tue, 21 Jul 2009 00:28:56 PDT Why do more complex viruses (e.g., HIV, AIDS-virus and SARS coronavirus) tend to be more fatal? The paper concludes that the cell fractal geometry of viruses is the key. This paper also suggests two possible new approaches using nanotechnology and temperature to cure or prevent virus infection Ji-Huan He biotechnology http://works.bepress.com/ji_huan_he/44 http://works.bepress.com/ji_huan_he/44 Tue, 21 Jul 2009 00:21:59 PDT This paper is an elementary introduction to the concepts of the homotopy perturbation method. Particular attention is paid to giving an intuitive grasp for the solution procedure throughout the paper. Ji-Huan He Homotopy perturbation method http://works.bepress.com/ji_huan_he/43 http://works.bepress.com/ji_huan_he/43 Sun, 07 Sep 2008 20:40:35 PDT This review is an elementary introduction to the concepts of the recently developed asymptotic methods and new developments. Particular attention is paid throughout the paper to giving an intuitive grasp for Lagrange multiplier, calculus of variations, optimization, variational iteration method, parameter-expansion method, exp-function method, homotopy perturbation method, and ancient Chinese mathematics as well. Subsequently, nanomechanics in textile engineering and E-infinity theory in high energy physics, Kleiber's 3/4 law in biology, possible mechanism in spider-spinning process and fractal approach to carbon nanotube are briefly introduced. Bubble-electrospinning for mass production of nanofibers is illustrated. There are in total more than 280 references Ji-Huan He review article http://works.bepress.com/ji_huan_he/42 http://works.bepress.com/ji_huan_he/42 Sat, 16 Aug 2008 18:47:36 PDT Similar to the nuclear age, the so-called nanoage is coming, the growing gap between nano haves and nano have-nots, however, will remain, as has global competition, particularly from the electrospinning technology. Ji-Huan He nanotechnology http://works.bepress.com/ji_huan_he/41 http://works.bepress.com/ji_huan_he/41 Sun, 10 Aug 2008 22:33:13 PDT Abstract BACKGROUND: Electrospinning is widely used to produce nanofibers; however, not every polymer can be electrospun into nanofibers. To enhance electrospinability, much effort has been made in designing new apparatus, such as vibration-electrospinning, magneto-electrospinning and bubble-electrospinning. RESULTS: A representative non-ionic surfactant, TritonR X-100, is used to enhance electrospinability. The surfactant is added to an electrospun poly(vinyl pyrrolidone) polymer solution, and a dramatic reduction in surface tension is observed. As a result, a moderate voltage is needed to produce fine nanofibers, which are commonly observed during the conventional electrospinning procedure only at elevated voltage. CONCLUSION: The novel strategy produces smaller nanofibers than those obtained without surfactants, and the minimum threshold voltage is much decreased. Copyright © 2008 Society of Chemical Industry Shu-Qiang Wang nanotechnology http://works.bepress.com/ji_huan_he/40 http://works.bepress.com/ji_huan_he/40 Tue, 29 Jul 2008 18:09:16 PDT We give the exact geometrical shape and study the combinatorial properties of higher dimensional polytopes for the dimensions from n = 4 to n = 12 as well n = 26 relevant to Heterotic, M and F superstring theories. Connections to E-infinity theory and the holographic principles are also discussed Ji-Huan He E-infinity Theory (El Naschie Space-time theory) http://works.bepress.com/ji_huan_he/39 http://works.bepress.com/ji_huan_he/39 Thu, 17 Jul 2008 00:07:44 PDT Some new exact solutions are obtained for the nonlinear dispersive K(m, n) equations using the exp-function method. The results show that the method is straightforward and concise and its applications are promising. Xin-Wei Zhou exp-function method