Processing Structure Morphology Property Relationships In Nano Scale Fibers And Their Biomedical Applications

Ultra high molecular weight polyethylene (UHMWPE) fibers are increasingly used in high -performance applications where strength, stiffness, and the ability to dissipate energy are of critical importance. Despite their use in a variety of applications, the influence of morphological features at the meso/nanoscale on the macroscopic performance of the fibers has not been well understood. There is particular interest in gaining a better understanding of the nanoscale structure-property relationships in UHMWPE fibers used in ballistics applications. In order to accurately model and predict failure in the fiber, a more complete understanding of the complex load pathways that dictate the ways in which load is transferred through the fiber, across interfaces and length scales is required. ☐ The goal of the work discussed herein is to identify key meso/nanostructural features evolved in high performance fibers and determine how these features influence the performance of the fiber through a variety of different loading mechanisms. The important structural features in high-performance UHMWPE fibers are first identified through examination of the meso/nanostructure of a series of fibers with different processing conditions. This is achieved primarily through the use of wide-angle x-ray diffraction (WAXD) and atomic force microscopy (AFM). Analysis of AFM images and WAXD data allows identification and quantifications of important structural features at these length scales. ☐ Key meso/nanostructural features are then examined with respect to their influence on the transverse compression behavior of single fibers. Through post-mortem AFM analysis of samples at incremental compressive strains, the evolution of damage is examined and compared with macroscopic fiber mechanical response. It was found that collapse of mesoscale voids, followed by nanoscale fibrillation and reorganization of a fibrillar network has a significant influence on the mechanical response of the fiber. Through this work, the importance of nanoscale fibril adhesive interactions is highlighted. However, very little information exists in the literature as to the nature and magnitude of these interactions. ☐ Examination of nanoscale fibrillar adhesive interactions is experimentally difficult, and necessitated the development of an AFM based nanoscale splitting technique to quantify the interactions between fibrils. Through analysis of split geometry and careful partitioning of energies, the adhesive energy between fibrils in UHMWPE fibers are determined. The calculated average adhesive energies are significantly larger than the estimated energy due to van der Waals interactions, suggesting that there are physical connections (e.g., tie chains, tie fibrils, and lamellar crystalline bridges) that influence the interactions between fibrils. The interactions identified through this work are believed to be responsible for the creation of load pathways across fibril interfaces where load may be translated through the fiber in tension, compression, and shear. ☐ Finally, the nature of the mesoscale fibrillar network is explored through the development of a variable angle, single fiber peel test. This peel test enables the quantification of Mode I and Mode II peel energies. The modes of deformation observed in the peel test are representative of the mechanisms experienced during tensile and transverse compression loading. The quantification of peel energies in both Mode I and Mode II failure highlight the importance of the fibrillar network as a key mechanism for the translation of load through the fiber. In both modes of failure, the fibril network acts as a framework for the orientation and subsequent failure of nanoscale fibrils.

This book titled Nanofiber Research - Reaching New Heights contains a number of latest research results on growth and developments on material fibers in nanoscale. It is a promising novel research area that has received a lot of interest in recent years. This book includes interesting reports on cutting-edge science and technology related to synthesis, morphology, control, self-assembly and prospective application of nanofibers. I hope that the book will lead to systematization of nanofiber science, creation of new nanofiber research field and further promotion of nanofiber technology. This potentially unique work offers various approaches on the implementation of nanofibers. As it is widely known, nanotechnology presents the control of matter at the nanoscale and nano-dimensions within few nanometers, whereas this exclusive phenomenon enables us to regulate and control novel applications with nanofibers. This book presents an overview of recent and current nanofibers fundamental, significant applications and implementation research worldwide. It examined the methods of nanofiber synthesis, types of fibers used and potential applications associated with nanofiber researches. It is an important booklet for research organizations, governmental research centers, academic libraries and R

Nanoscale Processing outlines recent advances in processing techniques for a range of nanomaterial types. New developments in the processing of nanostructured materials are being applied in diverse fields. This book offers in-depth information and analysis of a range of processing techniques for nanostructures, and also covers nanocharacterization aspects thoroughly. Topics covered include zero dimensional nanostructures, nanostructured biomaterials, carbon-based nanostructures, polymeric and liposomal nanostructures, and quantum dots. This book is an important resource for materials scientists and engineers looking to learn more about a variety of processing techniques for various nanomaterial classes, for use in both the industrial and biomedical sectors. Explains major nanoscale processing techniques, outlining in which situations each should be used Discuses a range of nanomaterial classes, including nanobiomaterials, polymeric nanomaterials, optical nanomaterials and magnetic nanomaterials Explores the challenges of using certain processing techniques for certain classes of nanomaterial

Connects fiber chemistry and structure to properties that can be designed and engineered Micro- and nanoscale, synthetic and natural polymer and non-polymer fibers explained with applications to industrial, electronic, biomedical and energy Information pertinent for fiber, textile, composite, polymer and materials specialists This volume provides the basic chemical and mathematical theory needed to understand and modify the connections among the structure, formation and properties of many different types of manmade and natural fibers. At a fundamental level it explains how polymeric and non-polymeric fibers are organized, how such fibers are formed, both synthetically and biologically, and how primary and secondary properties, from basic flow to thermal and electrical qualities, are derived from molecular and submolecular organization, thus establishing the quantitative and predictive relationships needed for fiber engineering. The book goes on to show how fiber chemistry and modes of processing for dozens of materials such as silks, ceramics, glass and carbon can be used to control functional optical, conductive, thermal and other properties. Its discussion ranges over microscale and nanoscale fibers (nanofibers), covering methods such as spinning and electrospinning, as well as biological fiber generation through self-assembly. Technologies in this text apply to the analysis and design of fibers for industrial, electronic, optical, medical and energy storage applications.

This book details all current techniques for converting bulk polymers into nano-size materials. The authors highlight various physical and chemical approaches for preparation of nano-size polymers. They describe the properties of these materials and their extensive potential commercial applications.

Author's abstract: In this work, investigations regarding the synthesis and fabrication of novel structural nanocomposite fibers and biocompatible nanofibers were performed. Characterization techniques such as scanning electron microscopy (SEM), energy dispersive x-ray spectroscopy (EDS), differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR) analysis were utilized to analyze the morphological structure of the fibers at the micro and nanoscale. Hybrid nanocomposite fibers from a blend of ultrahigh molecular weight polyethylene (UHMWPE), with Nylon-6 as a secondary polymer phase, combined with single-walled carbon nanotubes (SWCNT) were fabricated using a solution spinning process. Polyethylene-graft-Maleic Anhydride (PE-g-MAH) was used as a compatibilizer to modify the interaction of the immiscible polymer phases. Comparative characterization studies of fibers produced both with and without the inclusion of PE-g-MAH were performed to observe the effect of compatibilization on the morphological development of the fiber microstructure. SEM observations of compatibilized hybrid fibers showed rough and indistinct interfacial separation of the polymer phases. Coating of SWCNTs with polymer phase was observed, which were aligned along the direction of extrusion. DSC results indicated reduction of crystallinity, crystallization rate and lamellar size of the compatibilized blends. Comparative FTIR analysis showed the presence of absorbance peaks related to imide linkages between the UHMWPE backbone and Nylon-6 chains. The DSC and FTIR results indicated the formation of a coupling bond between the polymer phases combined with PE-g-MAH. For fabrication of biocompatible nanofibers as drug delivery systems, electrospinning techniques were utilized to produce neat and drug-loaded nanofibers from biocompatible polymers of cellulose, cellulose Acetate (CA) and poly(ethylene oxide) (PEO). Loading of model anti-cancer drugs, Cisplatin and 5-Fluorouracil into CA and PEO was performed using coaxial electrospinning. Morphological analysis of produced microstructures and fibers were performed using SEM and EDS. Cellulose nanofibers loaded with Cisplatin showed blends of polymer-drug particles attached to the surface of fibers. CA-Cisplatin fibers exhibited drug encapsulation within diverse morphological conformations: straw-sheaf microparticles, dendritic branched nanofibers and swollen fibers with large beads. PEO fibers loaded with Cisplatin and Fluorouracil showed encapsulation of drugs within repeating dumb-bell shaped reservoirs formed along the length of the nanofibers.

Introduction to cellulose nanocomposites; strategies for preparation of cellulose wiskers from microcrystalline cellulose as reinforcement in nanocomposites; self-assembly of cellulose nanocrystals: parabolic focal conic films; cellulose fibrils: isolation, characterization, and capability for technical applications; morphology of cellulose and its nanocomposites; useful insights into cellulose nanocomposites using raman spectroscopy; novel methods for interfacial modification of cellulose - reinforced composites; cellulose nanocrystals for thermoplastic reinforcement: effect of filler surface chemistry on composite properties; the structure and mechanical properties of cellulose nanocomposites prepared by twin screw extrusion; preparation and properties of biopolymer-based nanocomposites films using microcrystalline cellulose; nanocompusites based on cellulose microfibril; cellulose microfibers as reinforcing agents for structural materials; dispersion of soybean stock-based nanofiber in plastic matrix; polysulfone-cellulose nanocomposites; bacterial cellulose and its nanocomposites for biomedical applications.

Electrospun Nanofibers covers advances in the electrospinning process including characterization, testing and modeling of electrospun nanofibers, and electrospinning for particular fiber types and applications. Electrospun Nanofibers offers systematic and comprehensive coverage for academic researchers, industry professionals, and postgraduate students working in the field of fiber science. Electrospinning is the most commercially successful process for the production of nanofibers and rising demand is driving research and development in this field. Rapid progress is being made both in terms of the electrospinning process and in the production of nanofibers with superior chemical and physical properties. Electrospinning is becoming more efficient and more specialized in order to produce particular fiber types such as bicomponent and composite fibers, patterned and 3D nanofibers, carbon nanofibers and nanotubes, and nanofibers derived from chitosan. Provides systematic and comprehensive coverage of the manufacture, properties, and applications of nanofibers Covers recent developments in nanofibers materials including electrospinning of bicomponent, chitosan, carbon, and conductive fibers Brings together expertise from academia and industry to provide comprehensive, up-to-date information on nanofiber research and development Offers systematic and comprehensive coverage for academic researchers, industry professionals, and postgraduate students working in the field of fiber science

Hybrid nanostructures are nanoparticles which incorporate two or more structures. These structures may represent organic or inorganic material, but they synergistically improve the application of the material for end users. Hybrid Nanostructures for Cancer Theranostics explores how hybrid nanostructures are used in cancer treatment. Focusing on the properties of hybrid nanostructures, the book demonstrates how their unique characteristics can be used to create more effective treatment techniques. In the second half of the book, the chapters examine how hybrid nanostructures are currently being used in practice, assessing the pros and cons of using different types of nanostructures for different treatments. This valuable resource will allow readers to understand the core and emerging concept of functionalization, bioconjugation, hyperthermia and phototherapy of nanoparticles which allows for the greater use of hybrid nanomaterials in cancer theranostics. Shows how the use of novel hybrid nanostructures can lead to more effective cancer treatments. Explores how hybrid nanostructures are used for different treatment types, including photo thermal therapy and drug delivery. Explains how the use of hybrid nanostructures can lead to more rapid cancer diagnosis.