DOCSLIB.ORG

Electrospinning Polymer Nanofibers - Electrical and Optical

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Electrospinning Polymer Nanofibers - Electrical and Optical ELECTROSPINNING POLYMER NANOFIBERS - ELECTRICAL AND OPTICAL CHARACTERIZATION A dissertation presented to the faculty of the College of Arts and Science of Ohio University In partial fulfillment of the requirements for the degree Doctor of Philosophy Saima N. Khan November 2007 This dissertation titled ELECTROSPINNING POLYMER NANOFIBERS ─ ELECTRICAL AND OPTICAL CHARACTERIZATION by SAIMA N. KHAN has been approved for the Department of Physics and Astronomy and the College of Arts and Science by Martin E. Kordesch Professor of Physics and Astronomy Benjamin M. Ogles Dean, College of Arts and Science Abstract KHAN, SAIMA, Ph.D., November 2007, Physics and Astronomy ELECTROSPINNING POLYMER NANOFIBERS - ELECTRICAL AND OPTICAL CHARACTERIZATION (107 pp.) Director of Thesis: Martin E. Kordesch Electro spinning is a technique used for the production of thin continuous fibers from a variety of materials including polymers, composites and ceramics [1-3]. The extremely small diameters (~ nm) and high surface to volume and aspect ratios found in electrospun fibers can not be achieved through conventional spinning. Electrically conducting polymers are materials which simultaneously possess the physical and chemical properties of organic polymers and the electronic characteristics of metals. In this work fibers were electrospun from polymer blends of polyaniline doped with Camphorsulfonic acid (PAn.HCSA) and polyethylene oxide (PEO) in chloroform. Electrical conductivities of the fibers were measured using the four-point-probe method. The conductivities of the cast films were measured for comparison purposes. It was noticed that the conductivity of both the fibers and films increase exponentially with the concentration of (PAn.HCSA), the conductivity of the film however is higher than that of the mat for any given concentration of PAn.HCSA in PEO. Electrical conductivities of single fibers containing different PAn: HCSA concentrations were measured for the first time and were found to be the highest (3.2S/cm) among the mats and films. The effect of the non-conductive PEO on the conductivity of the polyaniline fibers was studied. Keeping the PAn.HCSA concentration constant films and fibers were obtained from blends containing PEO (300,000 g/mol) and PEO (900,000 g/mol). Higher electrical conductivities were recorded in fibers and mats containing PEO (900,000 g/mol) than those containing PEO (300,000 g/mol). Silicon Carbide (SiC) fibers were obtained by electrospinning a blend of SiC and PEO in chloroform and sintering the as spun fibers at temperatures of 800ºC and 1000ºC. The compositional analysis of the annealed samples confirmed the presence of (30-40) µm long SiC fibers with diameters in the range (1-3) µm. Optical spectra of the fibers show red emission extending to the infrared. For the first time complexes of ruthenium with picolinate and polypyridine ligands were introduced into nanofibers. Fibers containing ruthenium picolinate ([Ru (pic)2 (dmso)2]) turn orange from pale yellow on exposure to ultraviolet radiation (350nm). Fibers containing ruthenium bi-pyridine ([Ru(bpy)2](PF6)2) exhibit photoluminescence with steady state red emission upon 450 nm excitation. Approved: Martin E. Kordesch Professor of Physics and Astronomy Dedication To my father Mumtaz Khan, Who provided me a strong academic foundation and whose determination to provide me education serves as an inspirational example to a society and culture where women have always been underestimated and under-treated. He is not in this world any more but I hope he knows that I can’t be proud enough of being his daughter and that I love him as much as he loved me. Acknowledgements First and foremost I would like to express my heartfelt gratitude towards my supervisor Professor Martin E. Kordesch for his academic guidance, continuous support and encouragement throughout this project. He is a pleasant person, a remarkable teacher and a great human being. I appreciate his generosity in providing me the opportunity to attend various conferences that gave me good academic exposure. He has been very co- operative all along and gave me his precious time and advice whenever I needed it. I am very thankful to Dr. Saw Wai Hla, Dr. Alexander Neiman and Dr. P. G. Van Patten for being members of my thesis committee. I am sincerely thankful to Dr. Jeffery Rack for his help and co-operation in this work. My heartfelt gratitude extends to Dr. Aurangzeb Khan who makes me proud for being my loving husband, wonderful friend and a nice colleague. I can’t thank him enough for believing in me and making me believe in myself. I want to acknowledge the little sacrifices our lovely daughter Gulsanga Khan has been making every day, for three years now. I love her and I owe her every bit of the pride I take in my degree today. I want to offer a very special thanks to my mother and my brothers who always took pride in my academic achievements and facilitated me in all the ways possible. I offer my special thanks to my mother-in-law for her love and support. She is an extraordinary woman and truly believes in the value of education. I also want to thank my friends and relatives for their support and co-operation. 7 Table of Contents ABSTRACT....................................................................................................................... 3 DEDICATION................................................................................................................... 5 ACKNOWLEDGEMENTS ............................................................................................. 6 LIST OF FIGURES ........................................................................................................ 11 CHAPTER 1.................................................................................................................... 15 BACKGROUND AND EXPERIMENTAL TOOLS ................................................... 15 1.1 Introduction........................................................................................................... 15 1.2 Electrospinning ..................................................................................................... 16 1.3 Working principle................................................................................................. 21 1.4 Scanning electron microscope (SEM) .................................................................. 25 1.5 Transmission electron microscope (TEM)............................................................ 27 1.6 Energy dispersive x-ray spectrometry (EDX)....................................................... 29 1.7 Four-Point-Probe method of conductivity measurement...................................... 31 1.8 Cathodoluminescence ........................................................................................... 34 8 1.9 Conclusion ............................................................................................................ 34 CHAPTER2..................................................................................................................... 36 ELECTROSPINNING POLYETHYLENE OXIDE NANOFIBERS........................ 36 2.1 Introduction........................................................................................................... 36 2.2 Sample preparation and obtaining fibers .............................................................. 37 2.3 Important process parameters ............................................................................... 39 2.3.1 Applied voltage............................................................................................. 39 2.3.2 Distance between the nozzle and the collector ............................................. 42 2.4 Conclusion ............................................................................................................ 44 CHAPTER 3.................................................................................................................... 45 CONDUCTING POLYMER NANOFIBERS .............................................................. 45 3.1 Introduction........................................................................................................... 45 3.2 Different types of doping...................................................................................... 48 3.2.1 Redox doping................................................................................................ 48 3.2.2 Photo doping................................................................................................. 48 3.2.3 Charge-injection doping................................................................................ 48 3.2.4 Non-Redox doping or Protonic-acid doping................................................. 49 9 3.3 Polyaniline ............................................................................................................ 50 3.3.1 Oxidation states of polyaniline ..................................................................... 51 3.3.2 Doping polyaniline........................................................................................52 3.4 Sample preparation............................................................................................... 55 3.5 Electrospinning fibers........................................................................................... 56 3.6 Characterization of the nanofibers........................................................................ 57 3.7 Electrical Conductivity measurement..................................................................
Load more

Recommended publications
  • Electrospun Nanofibers for Neural Tissue Engineering Jingwei Xie Marshall University, [email protected]
    Marshall University Marshall Digital Scholar Faculty Research Marshall Institute for Interdisciplinary Research 1-1-2010 Electrospun Nanofibers for Neural Tissue Engineering Jingwei Xie Marshall University, [email protected] Matthew R. MacEwan Andrea G. Schwartz Younan Xia Follow this and additional works at: http://mds.marshall.edu/miir_faculty Part of the Medical Molecular Biology Commons, Medical Physiology Commons, and the Neurosciences Commons Recommended Citation Xie J., Macewan M. R., Schwartz A. G., Xia Y. 2010 Electrospun nanofibers for neural tissue engineering. Nanoscale 2, 35–44. doi:10.1039/b9nr00243j This Article is brought to you for free and open access by the Marshall Institute for Interdisciplinary Research at Marshall Digital Scholar. It has been accepted for inclusion in Faculty Research by an authorized administrator of Marshall Digital Scholar. For more information, please contact [email protected]. Feature article to Nanoscale, 8/2009 Electrospun nanofibers for neural tissue engineering Jingwei Xie, Matthew R. MacEwan, Andrea G. Schwartz and Younan Xia* Department of Biomedical Engineering, Washington University, St. Louis, MO 63130, USA *Address correspondence to: [email protected] Abstract Biodegradable nanofibers produced by electrospinning represent a new class of promising scaffolds to support nerve regeneration. We begin with a brief discussion on electrospinning of nanofibers and methods for controlling the structure, porosity, and alignment of the electrospun nanofibers. The methods include control of the nanoscale morphology and microscale alignment for the nanofibers, as well as the fabrication of macroscale, three-dimensional tubular structures. We then highlight recent studies that utilize electrospun nanofibers to manipulate biological processes relevant to nervous tissue regeneration, including stem cell differentiation, guidance of neurite extension, and peripheral nerve injury treatments.
    [Show full text]
  • Electrospun Nerve Guide Conduits Have the Potential to Bridge Peripheral Nerve Injuries in Vivo Received: 13 June 2018 Hanna K
    www.nature.com/scientificreports Corrected: Author Correction OPEN Electrospun nerve guide conduits have the potential to bridge peripheral nerve injuries in vivo Received: 13 June 2018 Hanna K. Frost 1,2, Tomas Andersson3, Sebastian Johansson3, U. Englund-Johansson4, Accepted: 22 October 2018 Per Ekström4, Lars B. Dahlin1,2 & Fredrik Johansson3 Published online: 13 November 2018 Electrospinning can be used to mimic the architecture of an acellular nerve graft, combining microfbers for guidance, and pores for cellular infltration. We made electrospun nerve guides, from polycaprolactone (PCL) or poly-L-lactic acid (PLLA), with aligned fbers along the insides of the channels and random fbers around them. We bridged a 10 mm rat sciatic nerve defect with the guides, and, in selected groups, added a cell transplant derived from autologous stromal vascular fraction (SVF). For control, we compared to hollow silicone tubes; or autologous nerve grafts. PCL nerve guides had a high degree of autotomy (8/43 rats), a negative indicator with respect to future usefulness, while PLLA supported axonal regeneration, but did not outperform autologous nerve grafts. Transplanted cells survived in the PLLA nerve guides, but axonal regeneration was not enhanced as compared to nerve guides alone. The infammatory response was partially enhanced by the transplanted cells in PLLA nerve grafts; Schwann cells were poorly distributed compared to nerve guide without cells. Tailor-made electrospun nerve guides support axonal regeneration in vivo, and can act as vehicles for co-transplanted cells. Our results motivate further studies exploring novel nerve guides and the efect of stromal cell-derived factors on nerve generation.
    [Show full text]
  • Spider Silk for Tissue Engineering Applications
    molecules Review Spider Silk for Tissue Engineering Applications Sahar Salehi 1, Kim Koeck 1 and Thomas Scheibel 1,2,3,4,5,* 1 Department for Biomaterials, University of Bayreuth, Prof.-Rüdiger-Bormann-Strasse 1, 95447 Bayreuth, Germany; [email protected] (S.S.); [email protected] (K.K.) 2 The Bayreuth Center for Colloids and Interfaces (BZKG), University of Bayreuth, Universitätsstraße 30, 95447 Bayreuth, Germany 3 The Bayreuth Center for Molecular Biosciences (BZMB), University of Bayreuth, Universitätsstraße 30, 95447 Bayreuth, Germany 4 The Bayreuth Materials Center (BayMAT), University of Bayreuth, Universitätsstraße 30, 95447 Bayreuth, Germany 5 Bavarian Polymer Institute (BPI), University of Bayreuth, Universitätsstraße 30, 95447 Bayreuth, Germany * Correspondence: [email protected]; Tel.: +49-0-921-55-6700 Received: 15 January 2020; Accepted: 6 February 2020; Published: 8 February 2020 Abstract: Due to its properties, such as biodegradability, low density, excellent biocompatibility and unique mechanics, spider silk has been used as a natural biomaterial for a myriad of applications. First clinical applications of spider silk as suture material go back to the 18th century. Nowadays, since natural production using spiders is limited due to problems with farming spiders, recombinant production of spider silk proteins seems to be the best way to produce material in sufficient quantities. The availability of recombinantly produced spider silk proteins, as well as their good processability has opened the path towards modern biomedical applications. Here, we highlight the research on spider silk-based materials in the field of tissue engineering and summarize various two-dimensional (2D) and three-dimensional (3D) scaffolds made of spider silk.
    [Show full text]
  • Morphology and Cell Compatibility of Regenerated Ornithoctonus Huwenna Spider Silk by Electrospinning
    Journal of Fiber Bioengineering and Informatics Regular Article Morphology and Cell Compatibility of Regenerated Ornithoctonus Huwenna Spider Silk by Electrospinning Zhi-Juan Pan*, Jun-Yan Diao, Jian Shi College of Material Engineering, Soochow University, 178 East Ganjiang Road, Suzhou 215021, P. R. CHINA Abstract: Ornithoctonus huwenna spiders can be bred in mass production, and potential applications of the spider silk in medical materials should be paid attentions. Regenerated nano-scale spider silk nonwovens were prepared by electrospinning from tanglesome Ornithoctonus huwenna spider silk. The morphologies of the electrospun spider silk fibers were investigated, and the cell compatibilities were explored. The results showed that the electric field strength was an important factor for the diameter, degree of crystal and molecular conformation of electrospun Ornithoctonus huwenna spider silk. With the increase of electric field strength, fibers became fine and even, and the crystallinity and β-sheet structure were improved. The electrospun nanofiber nonwoven had good compatibility with rat bone marrow stromal cells (rBMSCs). The cell survival rates were above 98% on the fiber surfaces. Keywords: Ornithoctonus huwenna spider, spider silk, electrospinning, molecular conformation, crystallinity, cell compatibility 1. Introduction Orb-web spiders secret unique silk fibers named as obtained as well for the following: vascular grafts, dragline silks from the major amplullate glands, which wound dressings or tissue engineering scaffolds
    [Show full text]
  • Producers of Machines for Electrospinning Usage of Electrospun Materials
    Výrobci zařízení pro elektrostatické zvlákňování Použití elektrostaticky zvlákněných nanovláken PRODUCERS OF MACHINES FOR ELECTROSPINNING USAGE OF ELECTROSPUN MATERIALS 5. přednáška MACHINES FOR ELECTROSPINNING ON MARKET Elmarco (Czech Republic) NS, NanospiderTM Three diferent spinning electrodes: Elmarco Laboratory devices – spinning from the wire http://www.youtube.com/watch?feature=player_embedded&v=R01BLyqrWlQ http://www.youtube.com/watch?v=IRc120Ceq9o&feature=player_embedded http://www.youtube.com/watch?feature=player_embedded&v=R01BLyqrWlQ Contipro (Czech Republic) 4SPIN® CONTIPRO GROUP CONTIPRO GROUP CONTIPRO GROUP Spinning electrodes Collectors CONTIPRO GROUP Electroblowing Technika kombinující elektrostatické zvlákňování s prouděním vzduchu kolem zvlákňovací elektrody Umožňuje: - úpravu klimatických podmínek kolem zvlákňovací elektrody -Snížení viskozity (při zvýšené teplotě proudícího vzduchu) -Zvýšení rychlosti odpařování rozpouštědla -Ovlivnění morfologie nanovláken -Atd. CONTIPRO GROUP 4SPIN video http://www.youtube.com/watch?feature=player_embedded&v=40W- WABZJaY SPUR (Czech Republic) SPIN Line http://www.spur-nanotechnologies.cz/video/Spur1.swf MECC (Japonsko) Nanon Zvlákňovací elektrody MECC Jehlová elektroda Jehlová elektroda - klipová - Pro malá množství roztoku Jehlová elektroda - koaxiální KOLEKTORY MECC Deskový Diskový Bubnový - Jádrovitý – pro výrobu tubulárních válcovitý nanovlákenných útvarů Prezentační video MECC http://www.youtube.com/watch?v=KBvHJs3A9k4&feature=player_ embedded FNM (Irán) Nanorassam ® (průmyslová
    [Show full text]
  • Multi-Functional Electrospun Nanofibers from Polymer Blends for Scaffold Tissue Engineering
    Michigan Technological University Digital Commons @ Michigan Tech Michigan Tech Publications 7-19-2019 Multi-functional electrospun nanofibers from polymer blends for scaffold tissue engineering Samerender Nagam Hanumantharao Michigan Technological University Smitha Rao Michigan Technological University, [email protected] Follow this and additional works at: https://digitalcommons.mtu.edu/michigantech-p Part of the Biomedical Engineering and Bioengineering Commons Recommended Citation Hanumantharao, S. N., & Rao, S. (2019). Multi-functional electrospun nanofibers from polymer blends for scaffold tissue engineering. Fibers, 7(7), 1-35. http://dx.doi.org/10.3390/fib7070066 Retrieved from: https://digitalcommons.mtu.edu/michigantech-p/532 Follow this and additional works at: https://digitalcommons.mtu.edu/michigantech-p Part of the Biomedical Engineering and Bioengineering Commons fibers Review Multi-Functional Electrospun Nanofibers from Polymer Blends for Scaffold Tissue Engineering Samerender Nagam Hanumantharao and Smitha Rao * Department of Biomedical Engineering, Michigan Technological University, Houghton, MI 49931, USA * Correspondence: [email protected] Received: 27 May 2019; Accepted: 12 July 2019; Published: 19 July 2019 Abstract: Electrospinning and polymer blending have been the focus of research and the industry for their versatility, scalability, and potential applications across many different fields. In tissue engineering, nanofiber scaffolds composed of natural fibers, synthetic fibers, or a mixture of both have been reported. This review reports recent advances in polymer blended scaffolds for tissue engineering and the fabrication of functional scaffolds by electrospinning. A brief theory of electrospinning and the general setup as well as modifications used are presented. Polymer blends, including blends with natural polymers, synthetic polymers, mixture of natural and synthetic polymers, and nanofiller systems, are discussed in detail and reviewed.
    [Show full text]
  • A Critique on Multi-Jet Electrospinning: State of the Art and Future Outlook Clothing and Fabrics Manufacture
    Nanotechnol Rev 2019; 8:236–245 Review Article Hosam El-Sayed*, Claudia Vineis, Alessio Varesano, Salwa Mowafi, Riccardo Andrea Carletto, Cinzia Tonetti, and Marwa Abou Taleb A critique on multi-jet electrospinning: State of the art and future outlook https://doi.org/10.1515/ntrev-2019-0022 clothing and fabrics manufacture. In 1738 Lewis Paul was Received Jan 29, 2019; accepted Jul 01, 2019 granted a patent for roller drafting spinning machinery [1]. Toward the end of the nineteenth century, the ring process Abstract: This review is devoted to discuss the unique char- was fairly well perfected, and its use was becoming stan- acteristics of multi-jet electrospinning technique, com- dard throughout the world. Ring spinning is about 250% pared to other spinning techniques, and its utilization in more productive than mule spinning and is simpler and spinning of natural as well as synthetic polymers. The less expensive to operate so; the mass production arose in advantages and inadequacies of the current commercial the 18th century with the beginnings of the industrial revo- chemical spinning methods; namely wet spinning, melt lution. spinning, dry spinning, and electrospinning are discussed. Yarns are usually spun from a various materials that The unconventional applications of electrospinning in tex- could be natural fibers viz., animal and plant fibers, or syn- tile and non-textile sectors are reported. Special empha- thetic ones. sis is devoted to the theory and technology of the multi- jet electrospinning as well as its applications. The current status of multi-jet electrospining and future prospects are outlined. Using multi-jet electrospinning technique, vari- 2 Types of spinning ous polymers have been electrospun into uniform blend nanofibrous mats with good dispersibility.
    [Show full text]
  • Electrospinning of Chitosan-Based Solutions for Tissue Engineering and Regenerative Medicine
    International Journal of Molecular Sciences Review Electrospinning of Chitosan-Based Solutions for Tissue Engineering and Regenerative Medicine Saad B. Qasim 1, Muhammad S. Zafar 2,3,* ID , Shariq Najeeb 4 ID , Zohaib Khurshid 5, Altaf H. Shah 6, Shehriar Husain 7 and Ihtesham Ur Rehman 8 1 Department of Restorative and Prosthetic Dental Sciences, College of Dentistry, Dar Al Uloom University, P.O. Box 45142, Riyadh 11512, Saudi Arabia; [email protected] 2 Department of Restorative Dentistry, College of Dentistry, Taibah University, Al Madinah, Al Munawwarah 41311, Saudi Arabia 3 Department of Dental Materials, Islamic International Dental College, Riphah International University, Islamabad 44000, Pakistan 4 Restorative Dental Sciences, Al-Farabi Colleges, Riyadh 361724, Saudi Arabia; [email protected] 5 College of Dentistry, King Faisal University, P.O. Box 380, Al-Hofuf, Al-Ahsa 31982, Saudi Arabia; [email protected] 6 Department of Preventive Dental Sciences, College of Dentistry, Dar Al Uloom University, Riyadh 11512, Saudi Arabia; [email protected] 7 Department of Dental Materials, College of Dentistry, Jinnah Sindh Medical University, Karachi 75110, Pakistan; [email protected] 8 Materials Science and Engineering Department, Kroto Research Institute, University of Sheffield, Sheffield S3 7HQ, UK; i.u.rehman@sheffield.ac.uk * Correspondence: [email protected] or [email protected]; Tel.: +966-50-754-4691 Received: 6 December 2017; Accepted: 24 January 2018; Published: 30 January 2018 Abstract: Electrospinning has been used for decades to generate nano-fibres via an electrically charged jet of polymer solution. This process is established on a spinning technique, using electrostatic forces to produce fine fibres from polymer solutions.
    [Show full text]
  • Electrospinning of Nanofibers and Their Applications
    MDT ‘Electrospinning’ ELECTROSPINNING OF NANOFIBERS AND THEIR APPLICATIONS Hale Karakaş1 1Istanbul Technical University, Textile Technologies and Design Faculty, İnönü cad., No: 65, Gümüşsuyu, Taksim, 34437, Istanbul/Turkey [email protected] Keywords: electrospinning, electrospun nanofibers, electrospinning parameters, functional nanofibers Abstract Electrospinning is a useful and efficient technique to produce ultrafine polymeric fibers. It has been a process of great scientific and industrial interest due to its versatility, cost- efficiency and potential to be used in a wide range of applications, resulting in an outstanding potential for nanotechnology research. As it is regarded as the most promising approach to produce continuous nanofibers on a large scale, a huge amount of work and study is observed to be carried out in this area both in academic and industrial circles, aiming to utilize the technology in a wide range of applications. The technique has been used with many synthetic and natural polymers. This training material on electrospinning gives detailed information on history of electrospinning, process theory and basic principles, parameters that influence the process and fiber morphology, advantages of superior properties and applications of electrospun nanofibers. In addition, the state-of-the-art, problems and limitations in this technology are evaluated. Recent progresses as well as future trends and challenges are discussed. 1 INTRODUCTION Electrospinning is a versatile and efficient method to produce continuous nanofibers from submicron diameters down to nanometer diameters by using a high potential electric field. It is possible to produce nanofibers with diameters ranging between a few nanometers to a few MDT 'Electrospinning' Electrospinning of nanofibers and their applications hundred nanometers thanks to the latest developments in electrospinning [1, 2].
    [Show full text]
  • Electrospinning Alginate-Based Nanofibers
    Carbohydrate Polymers 85 (2011) 111–119 Contents lists available at ScienceDirect Carbohydrate Polymers journal homepage: www.elsevier.com/locate/carbpol Electrospinning alginate-based nanofibers: From blends to crosslinked low molecular weight alginate-only systems Christopher A. Bonino a, Melissa D. Krebs b, Carl D. Saquing a, Sung In Jeong b, Kimberly L. Shearer a, Eben Alsberg b,c, Saad A. Khan a,∗ a Department of Chemical & Biomolecular Engineering, North Carolina State University, Raleigh, NC, United States b Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States c Department of Orthopaedic Surgery, Case Western Reserve University, Cleveland, OH, United States article info abstract Article history: We report here preparation of nanofibers containing alginate using two different molecular weights Received 20 October 2010 (MWs): 37 kDa and 196 kDa. Low MW alginates are attractive for in vivo tissue scaffolds where degrada- Received in revised form 12 January 2011 tion and clearance from the body are desirable, whereas higher MW alginates are amenable for topical Accepted 1 February 2011 use as wound coverage because of its better mechanical properties. We use polyethylene oxide (PEO) as Available online 26 February 2011 a carrier material to aid in electrospinning, and relate the solution properties, including entanglement concentration, relaxation time, conductivity, and surface tension, to their ability to be electrospun. In Keywords: addition, we examine an FDA-approved, nonionic surfactant as a route to enhancing the alginate–PEO Biomaterials Nanotechnology ratio (>80:20), and less toxic alternative to Triton X-100 surfactant. Finally, alginate-only nanofibers that Nanofibers are also water-insoluble are obtained by crosslinking the electrospun fibers with calcium and subse- Electrospinning quently removing the PEO and surfactants by soaking the nanofibers in water.
    [Show full text]
  • Fundamental Studies of Protein Ionization for Improved Analysis by Electrospray Ionization Mass Spectrometry and Related Methods
    Western Michigan University ScholarWorks at WMU Dissertations Graduate College 4-2014 Fundamental Studies of Protein Ionization for Improved Analysis by Electrospray Ionization Mass Spectrometry and Related Methods Kevin A. Douglass Western Michigan University, [email protected] Follow this and additional works at: https://scholarworks.wmich.edu/dissertations Part of the Organic Chemistry Commons Recommended Citation Douglass, Kevin A., "Fundamental Studies of Protein Ionization for Improved Analysis by Electrospray Ionization Mass Spectrometry and Related Methods" (2014). Dissertations. 240. https://scholarworks.wmich.edu/dissertations/240 This Dissertation-Open Access is brought to you for free and open access by the Graduate College at ScholarWorks at WMU. It has been accepted for inclusion in Dissertations by an authorized administrator of ScholarWorks at WMU. For more information, please contact [email protected]. FUNDAMENTAL STUDIES OF PROTEIN IONIZATION FOR IMPROVED ANALYSIS BY ELECTROSPRAY IONIZATION MASS SPECTROMETRY AND RELATED METHODS by Kevin A. Douglass A dissertation submitted to the Graduate College in partial fulfillment of the requirements for the degree of Doctor of Philosophy Department of Chemistry Western Michigan University April 2014 Doctoral Committee: Andre R. Venter, Ph.D., Chair John B. Miller, Ph.D. Yirong Mo, Ph.D. Blair R. Szymczyna, Ph.D. Bruce Bejcek, Ph.D. FUNDAMENTAL STUDIES OF PROTEIN IONIZATION FOR IMPROVED ANALYSIS BY ELECTROSPRAY IONIZATION MASS SPECTROMETRY AND RELATED METHODS Kevin A. Douglass, Ph.D. Western Michigan University, 2013 Mass spectrometry (MS) is an analytical technique in which a sample is converted to gas-phase ions that are subsequently separated and detected. It offers great speed, selectivity, and sensitivity during analysis, characteristics which have enabled it to become a leading method for the study of proteins.
    [Show full text]
  • 3Rd International Conference on Electrospinning August 4-7, 2014
    conference program 3rd International Conference on Electrospinning August 4-7, 2014 Westin San Francisco | San Francisco, CA www.ceramics.org/electrospin2014 Upgrade from your Current Electrospinning Rig l Best value on the market l Reproducible data, versatile instruments l Benefit from Spraybase® scientific expertise Contact your US Product Specialist Dimitri Leonidas [email protected] +1-857-526-1333 Cambridge, MA www.spraybase.com Spraybase® Electrospinning and Electrospraying Instruments Value | Versatility | Expertise Table of Contents Schedule At A Glance . 4 Plenary Speakers . 5 Hotel Map . 8 Sponsors . 8 Presenting Author List . 9–10 Final Program Tuesday Morning . 11 Tuesday Afternoon . 11–15 Wednesday Morning . 15–16 Wednesday Afternoon . 16–17 Thursday Morning . 18 Abstracts . 20 Author Index . 54 Program Committee Il-Doo Kim (KAIST) Younan Xia (Georgia Tech) Wolfgang Sigmund (Univ . of Florida) Jennifer Andrew, (Univ . of Florida) International Advisory Committee Jan Marijnissen, Delft Univ . of Technology, The Dario Pisignano, NNL, Univ . of Salento and Netherlands Institute Nanoscience-CNR, Italy You-Lo Hsieh, Univ . of California, Davis, USA Alexander L . Yarin, Univ . of Illinois at Chicago, Darrell Reneker, Univ . of Akron, USA USA Louis Kyratzis, CSIRO, Australia Seema Agarwal, Univ . of Bayreuth, Germany Robin Cranston, CSIRO, Australia Ce Wang, Jilin Univ ., China Yen Truong, CSIRO, Australia Xiumei Mo, Donghua Univ ., China Joachim H . Wendorff, Univ . of Marburg, Germany Eyal Zussman, Israel Institute of Technion, Israel Seeram Ramakrishna, National Univ . of Singapore, Tong Lin, Deakin Univ ., Australia Singapore Eugene Smit, Stellen bosch, South Africa Wolfgang Sigmund, Univ . of Florida, USA Andreas Szentivanyi, Leibniz Universität Jennifer Andrew, Univ . of Florida, USA Hannover, Germany Younan Xia, Georgia Tech, USA Jang Myoun Ko, Hanbat National Univ ., Korea Frank Ko, Univ .
    [Show full text]