Conductive Polymers
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1 Synthesis and Functionality of Substituted Polyacetylenes Jianzhao Liu, Jacky W
1 1 Synthesis and Functionality of Substituted Polyacetylenes Jianzhao Liu, Jacky W. Y. Lam, and Ben Zhong Tang 1.1 Introduction Polyacetylene (PA) is the archetypal conjugated polymer. The seminal discovery of the metallic conductivity of its doped form has triggered a huge surge of interest in conductive polymers and has spawned an exciting area of research on synthetic metals.1) As a result of rapid advances in the area, we are now on the threshold of a ‘‘plastic-electronics era’’ that previously could only be imagined in science fiction. Structurally, PA is a linear polyene chain [−(HC=CH)n−]. The existence of two hydrogen atoms in its repeat unit offers ample opportunity to decorate the backbone with pendants: replacement of hydrogen in each repeat unit by one or two substituents yields mono- (1) and disubstituted PAs (2), respectively (Scheme 1.1). The pendant and backbone can interact with each other: for example, the former perturbs the electronic conjugation of the latter, while the latter in- fluences the molecular alignment of the former. Proper structural design may tune the backbone–pendant interplay into harmony and synergy, generating new substituted PAs with novel functionalities. While PA is electrically conductive, introduction of such pendant as mesogen, chromophore, photosensitive double bond, or naturally occurring building block may endow it with such new func- tional properties as electro-optic activity, photonic responsiveness, and biologic compatibility. Considerable efforts have been devoted to the synthesis of the substituted PAs and study of their properties [1–9]. Attachment of polar groups to the polyene backbone enables the integration of functional pendants into the PA chain through various functional-group transformations, which was, however, a difficult task at the early stage of PA chemistry. -
Shape-Memory Polymeric Artificial Muscles Stress That Is Applied to the Polymer [8,70]
molecules Review Shape-Memory Polymeric Artificial Muscles: Mechanisms, Applications and Challenges 1, 1, 1, , 1 2 2 Yujie Chen y , Chi Chen y, Hafeez Ur Rehman * y, Xu Zheng , Hua Li , Hezhou Liu and Mikael S. Hedenqvist 3,* 1 State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China; [email protected] (Y.C.); [email protected] (C.C.); [email protected] (X.Z.) 2 Collaborative Innovation Centre for Advanced Ship and Dee-Sea Exploration, Shanghai Jiao Tong University, Shanghai 200240, China; [email protected] (H.L.); [email protected] (H.L.) 3 Department of Fibre and Polymer Technology, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden * Correspondence: [email protected] (H.U.R.); [email protected] (M.S.H.) These authors contributed equally to this work. y Academic Editor: Laura Peponi Received: 7 July 2020; Accepted: 3 September 2020; Published: 16 September 2020 Abstract: Shape-memory materials are smart materials that can remember an original shape and return to their unique state from a deformed secondary shape in the presence of an appropriate stimulus. This property allows these materials to be used as shape-memory artificial muscles, which form a subclass of artificial muscles. The shape-memory artificial muscles are fabricated from shape-memory polymers (SMPs) by twist insertion, shape fixation via Tm or Tg, or by liquid crystal elastomers (LCEs). The prepared SMP artificial muscles can be used in a wide range of applications, from biomimetic and soft robotics to actuators, because they can be operated without sophisticated linkage design and can achieve complex final shapes. -
Electronic Polymers
Electronic Polymers Insulators Semiconductors Metals Superconductors σ <10-7 10−7< σ <102 σ >102 σ >>1020 σ ranges 10-20 to 1020 Requires doping (oxidation or reduction) for conductivity Electrical Properties Electric conductivity of inorganic (I) and organic (O) compounds, I O measured in S/cm. Triniobium germanide (Nb3Ge) and poly(thiazyl) (SN)n are superconducting materials at very low temperatures near 20 zero kelvin. The conductivities for conducting (C), semi-conducting S Nb3Ge, (SN)n 10 (SC) and insulating (I) compounds are given for 20oC (= 293.16 K = 68oF). Cu = Copper, Hg = mercury, Ge = germanium, Si = silicon, 1015 AgBr = silver bromide, G = glass, S = sulfur, (SiO2)n= quartz, TTF = tetrathiafulvalene, TCNQ = 7,7,8,8 tetracyanoquinodimethane, NBR C 1010 = nitrile rubber (a copolymer from acrylonitrile and butadiene), DNA = deoxyribonucleic acid, PVC = polyvinyl chloride, PE = polyethylene, PTFE = polytetrafluoroethylene. Cu 105 TTF/TCNQ Hg 1 Siemens = 1 Ohm-1 (SN)n 1 Ge 1040 change in material property ! SC dP Si 10-5 AgBr Material Conductivity (S/cm) NBR -10 G 10 -7 DNA Insulators σ < 10 PVC 10-15 Semiconductors 10−7 < σ < 102 I S (SiO ) PE 2 n Metals σ > 102 10-20 PTFE Superconductors σ >> 1020 n = # carriers/cm3 Figure by MIT OCW. σ = nμq μ= mobility (cm2/V•sec) q = charge Types of Charge • Usual carriers: electrons, holes, ions(cations & anions) • New for conducting polymers – solitons, polarons, bipolarons Ji = σijEj where Ji is the current, σij is the conductivity and Ej is the applied field Battery Application – Li-polymer vs Pb. – Weight: 1/10th – volume: 1/3rd – power density: 10x – processable into any shape; dry, no toxic fumes etc. -
A Scientific Jackpot: the Nobel Prize for Penn Trio a Gentleman Dr
See the back page UNIVERSITY of PENNSYLVANIA for more Tuesday, on the October 17, 2000 Nobel Laureate, Volume 47 Number 8 Alan MacDiarmid. www.upenn.edu/almanac/ Toasting A Chemist and A Scientific Jackpot: The Nobel Prize for Penn Trio A Gentleman Dr. Alan G. MacDiarmid, structure. For a polymer to conduct electric current, it must “A Penn Nobel Blanchard Professor of Chem- consist alternately of single and double bonds between the Prize,”... “based on istry, is one of three recipients carbon atoms. It must also be “doped,” which means that great applied and of the 2000 Nobel Prize in electrons are removed (through oxidation) or introduced basic science,” is Chemistry. Sharing the honor (through reduction). These “holes,” or extra electrons, can how Roy Vagelos are former Penn professor Dr. move along the molecule, making it electrically conductive. described the accom- Alan J. Heeger, now at the Uni- Drs. MacDiarmid, Heeger, and Shirakawa were respon- plishment of “one of versity of California at Santa sible for the 1977 synthesis and the electrical and chemical our best teachers and Barbara, and Dr. Hideki doping of polyacetylene, the prototypical conducting poly- researchers.” Shirakawa, of the University of mer, and the rediscovery of polyaniline, now the foremost Tsukuba in Japan. industrial conducting polymer. They have subsequently de- “It’s an understate- The work underlying the veloped conductive polymers into a research field of great ment that we’ve award—which showed that importance for chemists as well as physicists. The area has been waiting for this plastics can be made to conduct also yielded important practical applications. -
A Brief History of Molecular Electronics
COMMENTARY | FOCUS A brief history of molecular electronics Mark Ratner The field of molecular electronics has been around for more than 40 years, but only recently have some fundamental problems been overcome. It is now time for researchers to move beyond simple descriptions of charge transport and explore the numerous intrinsic features of molecules. he concept of electrons moving conductivity decreased exponentially with Conference by one of the inventors of through single molecules comes layer thickness, therefore revealing electron the STM how to account for the fact Tin two different guises. The first is tunnelling through the organic monolayer. that charge could actually move through electron transfer, which involves a charge In 1974, Arieh Aviram and I published fatty acids containing long, saturated moving from one end of the molecule to the first theoretical discussion of transport hydrocarbon chains. the other1. The second, which is closely through a single molecule8. On reflection The first significant work attempting related but quite distinct, is molecular now, there are some striking features about to measure single-molecule transport charge transport and involves current this work. First, we suggested a very ad came from Mark Reed’s group at Yale passing through a single molecule that is hoc scheme for the actual calculation. University, working in collaboration with strung between electrodes2,3. The two are (This was in fact the beginning of many James Tour’s group, then at the University related because they both attempt -
Synthetic and Mechanistic Studies of Poly(Vinyl Chloride) and Some Other Chlorinated Polymers XIANLONG GE College of William &A
Synthetic and Mechanistic Studies of Poly(vinyl chloride) and Some Other Chlorinated Polymers XIANLONG GE College of William & Mary, Department of Applied Science, 2003 Field: Polymer Science, Degree: Ph.D. Advisor: William H. Starnes, Jr., Professor of Chemistry Abstract Poly(1,2-dichloroethylene) (PDCE) is an unknown polymer that should be a superb engineering thermoplastic for use in a variety of high-performance applications. This thesis discusses approaches to its synthesis and describes the preparation and some of the properties of a number of new polymers that contain chlorine. Other major topics addressed here are (a) the involvement of an excited cation diradical intermediate in the thermal degradation of poly(vinyl chloride) (PVC) and (b) the mechanism of the thermal stabilization of PVC by “plasticizer thiols”. Unlike vinyl chloride, 1,2-dchloroethylene (DCE) undergoes dimerization under free-radical conditions. Chain transfer to DCE by β-Cl elimination was shown to be the major reason for its nonpolymerization. The dimeric radical rearranges by a 1,2-Cl shift, but apparently to only a very minor extent. During the chlorination of alkyl chlorides with molecular chlorine, a bridged intermediate is involved, and for this reason, vicinal chlorides were found to be the major products. The yields of geminal chlorides increased significantly in the presence of solvents that form complexes with chlorine atoms, but such solvents also decreased the reactivity of the chlorination. Thus the chlorination of PVC in the presence of complexing solvents was not a useful method for the synthesis of PDCE Polyacetylene (PA) was prepared by the methods of both Shirakawa and Luttinger. -
Effect of Polythiophene Content on Thermomechanical Properties of Electroconductive Composites
molecules Article Effect of Polythiophene Content on Thermomechanical Properties of Electroconductive Composites Katarzyna Bednarczyk 1 , Tomasz Kukulski 2 , Ryszard Fryczkowski 2 , Ewa Schab-Balcerzak 1,3 and Marcin Libera 1,* 1 Institute of Chemistry, University of Silesia in Katowice, 9 Szkolna Str., 40-006 Katowice, Poland; [email protected] (K.B.); [email protected] (E.S.-B.) 2 Faculty of Materials, Civil and Environmental Engineering, University of Bielsko-Biala, Willowa 2 Str., 43-309 Bielsko-Biala, Poland; [email protected] (T.K.); [email protected] (R.F.) 3 Centre of Polymer and Carbon Materials, Polish Academy of Sciences, 34 M. Curie-Sklodowskej Str., 41-819 Zabrze, Poland * Correspondence: [email protected]; Tel.: +48-50-518-7647 Abstract: The thermal, mechanical and electrical properties of polymeric composites combined using polythiophene (PT) dopped by FeCl3 and polyamide 6 (PA), in the aspect of conductive constructive elements for organic solar cells, depend on the molecular structure and morphology of materials as well as the method of preparing the species. This study was focused on disclosing the impact of the polythiophene content on properties of electrospun fibers. The elements for investigation were prepared using electrospinning applying two substrates. The study revealed the impact of the substrate on the conductive properties of composites. In this study composites exhibited Citation: Bednarczyk, K.; Kukulski, ◦ good thermal stability, with T5 values in the range of 230–268 C that increased with increasing T.; Fryczkowski, R.; Schab-Balcerzak, PT content. The prepared composites exhibited comparable PA Tg values, which indicates their E.; Libera, M. -
12TH ASIAN CHEMICAL CONGRESS (12ACC) 2007 Registration Form
No. 1 / 2007 ■ Kuwait Chemical Society Symposium on Application of Catalyst in the Industry ■ 2006 Activities and 2007 President Profiles of the Member Societies www.facs-as.org Federation of Asian Chemical Societies Newsletter | No. 1 / 2007 ontents Obituary ■ Dr. Tan Sri B C Sekhar (1929 – 2006) 4 ■ Prof. Hitoshi Ohtaki (1932 – 2006) 6 Special Symposium ■ Kuwait Chemical Society Symposium on Application of Catalyst in the Industry (Fuel, Pollution and Drugs) 9 Biofuels: Emerging Renewable Energy for the Transportation Sector 10 Discrete Physico-Chemical Processes that Characterise Water Pollution 13 Peptide-Cleaving Catalyst as a New Paradigm in Drug Discovery 16 2006 Activities and 2007 President Profiles of the Member Societies ■ Brunei Darussalam Institute of Chemistry 18 ■ Chinese Chemical Society 20 ■ Hong Kong Chemical Society 22 ■ Institut Kimia Malaysia 23 ■ Korean Chemical Society 27 ■ New Zealand Institute of Chemistry 29 ■ Royal Australian Chemical Institute 32 FACS Activities ■ Minutes of the 49th EXCO Meeting 34 ■ FACS Project Reports Asian Chemicla Education Network (ACEN) 41 Asian Network for Environmental chemistry (ANEC) 42 Low-Cost Instrumentation-Microscale Chemistry (LCI-MSC) 47 Meeting Announcement: The 12th Asian Chemical Congress 49 Directories ■ FACS EXCO Members (2005-2007) 55 ■ Member Societies 56 ■ Project Directors (2006-2007) 58 ■ FACS Fellows 59 ■ FACS Life-time Members 60 An electronic version of FACS Newsletter is available at http://www.facs.org. Obituary The Late Academician Dr. Tan Sri B C Sekhar (1929 – 2006) he Late academician Dr. Tan Sri B C Sekhar, born on November 17, 1929 at Sungai Buloh, Malaysia near the 3,400-acre experiment station of the Rubber Research Institute of Malaysia (RRIM), was fondly known as Mr Natural Rubber for his motivation, passion and commitment to the development of natural rubber industry. -
Polyacetylene: Myth and Reality
materials Review Polyacetylene: Myth and Reality Bruce S. Hudson Department of Chemistry, Syracuse University, Syracuse, NY 13244-4100, USA; [email protected]; Tel.: +1-315-443-5805 Received: 31 December 2017; Accepted: 31 January 2018; Published: 6 February 2018 Abstract: Polyacetylene, the simplest and oldest of potentially conducting polymers, has never been made in a form that permits rigorous determination of its structure. Trans polyacetylene in its fully extended form will have a potential energy surface with two equivalent minima. It has been assumed that this results in bond length alternation. It is, rather, very likely that the zero-point energy is above the Peierls barrier. The experimental studies that purport to show bond alternation are reviewed and shown to be compromised by serious experimental inconsistencies or by the presence, for which there is considerable evidence, of finite chain polyenes. In this view, addition of dopants results in conductivity by facilitation of charge transport between finite polyenes. The double minimum potential that necessarily occurs for polyacetylene, if viewed as the result of elongation of finite 1 1 chains, originates from admixture of the 1 Ag ground electronic state with the 2 Ag excited electronic singlet state. This excitation is diradical (two electron) in character. The polyacetylene limit is an 1 equal admixture of these two Ag states making theory intractable for long chains. A method is outlined for preparation of high molecular weight polyacetylene with fully extended chains that are prevented from reacting with neighboring chains. Keywords: polyacetylene; double-minimum potential; Peierls barrier; zero-point level; cross-linking 1. Introduction/Background History Polyacetylene is selected for review because of its relative simplicity; the small periodic repeat permits polyacetylene to be treated by sophisticated computational methods. -
2020 Research Highlights
2020 RESEARCH HIGHLIGHTS FROM THE SCHOOL OF CHEMICAL SCIENCES A word from the Head The year 2020 presented our School with multiple challenges, yet our teaching and research was able to continue in a sometimes revised form. We have seen research teams and spin-off companies pivot to COVID-19 – related research and development. All our researchers have adapted to working in new environments, including bubbles at Level 3 and decreased laboratory occupancies at Level 2. Staff and students have also maintained their overseas and domestic collaborations and many have found their home offices can be productive writing spaces. We decided that one way we could celebrate our resilience and The School has an international reputation in natural products productivity in research this year was to produce this report chemistry and medicinal peptide chemistry and also in the highlighting our successes. We share the continued successes of development of potential metal-containing anticancer drugs. Our our high-profile researchers such as Distinguished Professor Dame materials chemistry expertise has resulted in the development of gas Margaret Brimble FRS, while also noting the contributions of our sensors which are now being incorporated in reliable sensing networks newest academics, research fellows and PhD students. Our research and photocatalysts. is heading in exciting new directions including new medications, developing novel states of matter, connecting electronics to cells, and Besides the success of individual research groups, our multi- modelling the behaviour of proteins. We support the range of activities investigator programmes and centres provide a foundation for joint from blue skies single investigator-led research to teams focused on funding bids and research publications. -
Conductive Nanocomposite Fabrication by Graphene Enriched Polypropylene Master Batch
© 2015 IJEDR | Volume 3, Issue 4 | ISSN: 2321-9939 Conductive Nanocomposite fabrication by Graphene enriched Polypropylene Master Batch 1M.Naushad Ali, 2H.Alamri, 3Abdul Wahab 1 Bottom Up Technologies Corporation, Jharkhand, India 2Physics Deptt, Umm Al-Qura University, Makkah, KSA 3Engineering Grad Trainee, Jharkhand Rai UniversitSy, Ranchi, India ________________________________________________________________________________________________________ Abstract - The nanocomposites are the most attentive topic of the study currently in the material science world which is likely to bring the industrial revolution. Graphene reinforced polypropylene nanocomposite was fabricated in the balanced formulation of filler & carrier additives through melt mixing process at the trend of industrial practices. The concept of molecular arrangement was hypothesized and executed out practically. The master batch was prepared as the primary preparatory work using Twin Screw Extruder and the finished product was obtained by using the same master batch through injection molding. The percolation threshold was considered to be 5% wt. Graphene in finished product which has been proved as the innovative product line. A series of destructive and non-destructive tests and characterization techniques were conducted, analyzed and presented. First time the entire range of properties has been explored including electrical, thermal, gas barrier & mechanical properties. The resulted product has proven to be used at the industrial scale immediately and has opened the new directions in making use of other class of polymers innovatively. Key words - Nanocomposite, Electrical conductivity, Graphene, Polypropylene, Industrial applications, Nanotechnology I. Introduction Nanomaterials own the Quantum confinement which consequences the exceptional outstanding properties and lead to the enormous range of revolutionary applications. In this regard, the discovery of graphene and graphene-based polymer nanocomposites is playing a vital role in modern science and technology [1]. -
FLEXIBLE ELECTRONICS: MATERIALS and DEVICE FABRICATION
FLEXIBLE ELECTRONICS: MATERIALS and DEVICE FABRICATION by Nurdan Demirci Sankır Dissertation submitted to the Faculty of Virginia Polytechnic Institute and State University In partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY in Materials Science and Engineering APPROVED: Richard O. Claus, Chairman Sean Corcoran Guo-Quan Lu Daniel Stilwell Dwight Viehland December 7, 2005 Blacksburg, Virginia Keywords: flexible electronics, organic electronics, organic semiconductors, electrical conductivity, line patterning, inkjet printing, field effect transistor. Copyright 2005, Nurdan Demirci Sankır FLEXIBLE ELECTRONICS: MATERIALS and DEVICE FABRICATION by Nurdan Demirci Sankır ABSTRACT This dissertation will outline solution processable materials and fabrication techniques to manufacture flexible electronic devices from them. Conductive ink formulations and inkjet printing of gold and silver on plastic substrates were examined. Line patterning and mask printing methods were also investigated as a means of selective metal deposition on various flexible substrate materials. These solution-based manufacturing methods provided deposition of silver, gold and copper with a controlled spatial resolution and a very high electrical conductivity. All of these procedures not only reduce fabrication cost but also eliminate the time-consuming production steps to make basic electronic circuit components. Solution processable semiconductor materials and their composite films were also studied in this research. Electrically conductive, ductile, thermally and mechanically stable composite films of polyaniline and sulfonated poly (arylene ether sulfone) were introduced. A simple chemical route was followed to prepare composite films. The electrical conductivity of the films was controlled by changing the weight percent of conductive filler. Temperature dependent DC conductivity studies showed that the Mott three dimensional hopping mechanism can be used to explain the conduction mechanism in composite films.