川大高分子科学导论——功能高分子

1 Chapter Chapter 77 Functional PolymersFunctional Polymers 高分子科学导论  Conducting and SemiConducting and Semi--conducting Functional conducting Functional PolymerPolymer导电和半导体功能高分子  Functional Polymer Materials for Adsorption and Functional Polymer Materials for Adsorption and SeparationSeparation吸附分离功能高分子  SuperabsorbentSuperabsorbent Resin Resin 高吸水性树脂  Functional Polymer with Functional Polymer with PhotoelectronicPhotoelectronic PropertiesProperties 光电功能高分子  Biomedical PolymersBiomedical Polymers生物医用高分子  Polymeric Liquid CrystalPolymeric Liquid Crystal高分子液晶  Ionic PolymersIonic Polymers 离子型聚合物 Discovery and development of conductive polymers The Nobel Prize in Chemistry 2000 Alan J. Heeger, Alan G. MacDiarmid, Hideki Shirakawa The Nobel Prize in Chemistry 2000 In the early days, the 1970s, we were laying out the initial discoveries and then building up the framework of the field. ....... Around 1990 this led to the discovery of LEDs, the application that was discovered in Cambridge by Richard Friend and his collaborators and that created one focus of much of the work in the 1990s. A second focus was the work on soluble polyaniline. There had been a lot of discussion suggesting that organic polymer metals would never be stable and never be processable. In the early 1990s, Cao, Smith, and I published a series of papers showing that it could be done. http://www.esi- topics.com/conducting- polymers/interviews/Dr-Alan- Heeger.html 7.1 Conducting and Semi-conducting Functional Polymer 7.1 Conducting and Semi-conducting Functional Polymer 导电功能高分子 半导体功能高分子 ● ●  Polymers are generally NOT good conductors of electricity  However, electrical conductivity is desired in various polymer applications:  Electostatic painting, lightning strike protection, etc. Conductive PolymersConductive Polymers 2 The Dream: Electronics on PlasticThe Dream: Electronics on Plastic Replace this . . . $10 billion $100 . . . with this Economics Replace this . . . . . . with this Flexible circuitry Ease of Production + - Chemical Versatility Replace this . . . . . . with this The Dream: Electronics on PlasticThe Dream: Electronics on Plastic You could deposit conducting polymer inks? + - Many conducting polymers are air/moisture-sensitive, they don't stick well, and are often quite expensive. Instead, could you use ion- implantation to modify the conductivity of plastic, just like we do with Silicon already! And so develop a cheap and simple way to create conducting plastics? Conducting PolymersConducting Polymers • Early 1970’s: Mistake in Skirakawa’s lab leads to accidental discovery of silver looking polymer (polyacetylene) • 2000: Heeger, MacDiarmid and Shirakawa win Nobel Prize in Chemistry • Late 1970’s: Collaboration between Heeger, MacDiarmid and Shirakawa lead to 10 million-fold increase in conductivity of polyacetylene. • 2000+: First ‘organic electronics’ appear on the market as flexible displays. Conductive PolymersConductive Polymers PolyacetylenePolyacetylene (PA)(PA) conductive polymerconductive polymer  nEarly 1970’s: Mistake in Skirakawa’s lab leads to accidental discovery of silver looking polymer (polyacetylene) Conductive PolymersConductive Polymers PolypyrrolePolypyrrole ((PPyPPy))–– conductive polymerconductive polymer  oxidationoxidation--reduction reduction reaction when voltage reaction when voltage is appliedis applied  redoxredox induces ion flow induces ion flow into or out of polymerinto or out of polymer  flow in = expansionflow in = expansion  requires electrolyterequires electrolyte N n Prior Art Making Plastics Conductive Prior Art Making Plastics Conductive 10 m Carbon nanofibers  Carbon nanofibers:  Highly conductive, but nonuniform dispersion and/or degraded aspect ratio 10 m Aluminum powder  Conductive powders: micro-sized metal filings, carbon black, etc.  Mixes well, but high loading is required Melt Blending or High Shear Melt Compounding Heated, high shear mixer 3 UDRI Technology DescriptionUDRI Technology Description “Method of Forming Conductive Polymeric Nanocomposite Materials and Materials Produced Thereby” (U.S. Patent Application 2003/0039816 A1) Solvent removal Filaments Coatings Thin or thick films Tubes Panels Composites carbon nanofibers • Polymer resin • Affordable carbon nanofibers • Solvent Ambient Temperature Dispersion process AdvantagesAdvantages  2-3 orders of magnitude more conductive than that produced by melt blending  Electronic percolation threshold < 1%  Use of affordable carbon nanofibers Large aspect ratio retained Uniform dispersion achieved Conductive PolymersConductive Polymers PolypyrrolePolypyrrole ((PPyPPy))–– conductive polymerconductive polymer  performance for performance for PPyPPy bilayerbilayer actuatoractuator  strain: 12.4%strain: 12.4%  energy density: 0.040 J/genergy density: 0.040 J/g  speed: <1Hzspeed: <1Hz  output pressure: 22 output pressure: 22 MPaMPa  drive voltage: +/drive voltage: +/-- 1V1V 7.2 Functional Polymer Materials for Adsorption and Separation 7.2 Functional Polymer Materials for Adsorption and Separation 吸附分离功能高分子● Ion -exchangersIon -exchangers  Synthetic organic polymer resins based on styrene – or acrylic-acid-type monomers are most widely used.  Generally solid gels in spherical or granular form consisting of: 1) A 3-dimensional polymeric network, 2) Ionic functional groups attached to the network, 3) Counterions 4) A solvent  Strong-acid, cation-exchange resins and strong-base anion exchange resins can be produced. Ion -exchangersIon -exchangers Styrene 苯乙烯 Divinylbenzene 对二乙烯基苯 4 Ion -exchangersIon -exchangers Introducing ionic functional groups into resins – sulfonation to a cation exchanger Introducing ionic functional groups into resins – chloromethylation and amination to an anion exchanger 7.3 Superabsorbent Resin7.3 Superabsorbent Resin 高吸水性树脂● Diaper Making MachineDiaper Making Machine (www.giga.com/~cricher/carlos.html) The Finished ProductThe Finished Product (Krafchik,2000) Components of The DiaperComponents of The Diaper  Polyethylene: the outside,breathable, leakproof  Polypropylene: against baby’s skin, keeps skin dry  Polyurethane聚氨基甲 酸酯: elastic on cuffs  Polyacrylate: Super Absorbent Polymers, absorb 30x their weight  Cellulose: draws liquid into the center  Glue: holds diaper together, made of resin and oil (Krafchik, 2000) 5 LandfillsLandfills  How much?  Diaper is the third largest consumer item in landfills  It equals 30% non- biodegradable waste in landfills  2% total municipal solid waste  Each baby contributes 1 ton of garbage (Sanders, 2001) 7.4 Functional Polymer with Photoelectronic Properties 7.4 Functional Polymer with Photoelectronic Properties 光电功能高分子● 7.5 Biomedical Polymers7.5 Biomedical Polymers 生物医用高分子● Molecules in Biomaterials and Tissue Engineering Molecules in Biomaterials and Tissue Engineering Polymeric Biomaterials are used in a Broad Range of Products Replacement of soft tissues: skin, blood vessels, cartilage, ocular lens 镜片, sutures 缝合 Orthopedic 整形外科 Polymers Nylon Synthetic rubber Crystalline polymers Heart valves and joint implants 心脏瓣膜和关节置换 Composites Carbon-carbon fibers and matrices Dental and orthopedic 牙科和整形外科 Ceramics Aluminum oxide Carbon Hydroxyapatite羟基磷灰石 ApplicationsBiomaterials Table Classification of biomaterials in terms of their base structure and some of their most common applications. 6 Figure These titanium-alloy joint replacements are an example of the many applications for metal biomaterials for implantations Catheters, sutures Poly(amides) (Nylons) Bioresorbable sutures, surgical products, controlled drug release Poly(esters) Artificial vascular graft, sutures, heart valves Poly(ethylene terephthalate) (PET) Coat implants, film, tubing Poly(urethanes) (PU) Blood bags, catheters, cannulaePoly(vinyl chloride) (PVC) Intraocular lens, dentures, bone cement Poly(methyl methacrylate) (PMMA) Bags, tubing Nonwoven fabric, catheter Orthopedic and facial implants Poly(ethylene) (PE) Low density (LDPE) High density (HDPE) Ultra high molecular weight (UHMWPE) ApplicationBiomedical polymer Table The clinical uses of some of the most common biomedical polymers relate to their chemical structure and physical properties. Vinyl Polymers polypropylene polystyrene polyvinylchloride polymethylmethacrylate Chemical Structure of Some Common Polymers Poly(ethylene terephthalate) “PET” Poly(carbonate) Figure This artificial heart valve is coated with Silizone, a biocompatible material that allows the body to accept the implant DENDRIMERSDENDRIMERS 7 DendrimerDendrimer  The word dendrimer comes from the Greek for tree, ‘dendra’.  It is an artificially produced polymer made up of branched monomer units.  They have many commercial applications and are an active area of research. Core = Core = Ion or Ion or Aromatic RingAromatic Ring Molecular Structure Molecular Structure Aromatic or Aliphatic Aromatic or Aliphatic PolyesterPolyester Fluorinated Surface Fluorinated Surface GroupsGroups Radius: Radius: rr 8< r < 178< r < 17ÅÅ Schematic Representation of Dendrimer Structure Dendrimer SynthesisDendrimer Synthesis 1 2 3 4 5 Generation 1 2 3 4 5 6 Terminal Groups 12 Terminal Groups 24 Terminal Groups 48 Terminal Groups 96Terminal Groupsx 2 x 2 x 2 x 2 RDA Generation Generation Generation Generation NUMBER OF TERMINAL GROUPS vs. DISTANCE RDA ET = 1 1 + R0 6  “Dendrimer synthesis is a field of polymer chemistry defined by regular, highly branched monomers leading to a monodisperse, tree-like or generational structure.”  Synthesis achieved through a step-wise reaction. Drug Delivery by DendrimersDrug Delivery by Dendrimers Dendrimers (code named “smart bombs”)  Targeting cancer cells (ignore normal ones)  Able to enter cells  Little toxicity Focus:  High energy lasers or sound wave to trigger the release of the drug out of the dendrimer. Polyfunctional Tecto-dendrimers: (connected PAMAM units) Polyfunctional Tecto-dendrimers: (connected PAMAM units)  Each “spore” in this “smart bomb” has its function:  Sensing and binding the target (cancer cells).  Emitting a signal (imaging).  Drug delivery in situ.  Low toxicity 8 7.6 Polymeric Liquid Crystal7.6 Polymeric Liquid Crystal 高分子液晶 Typical applicationsTypical applications  LCD displays LCD显示  Dyes (cholesterics) 染料（胆甾醇）  Advanced materials (Kevlar, Vectra) 先进材料  Membrane  Temperature measurement (by changing colors) 温度测量（通过颜色变化） back 7. Liquid crystals: Structure and properties 7. Liquid crystals: Structure and properties Classification of Liquid CrystalsClassification of Liquid Crystals Way to achieve LC State 液晶态实 现的方式 Thermotropic Liquid Crystalline 热致液晶 Lyotropic liquid crystal溶致液晶 Nematic Phases向列型 Smectic Phases近晶型 Cholesteric Phases胆甾型 Columnar Phases圆柱型 Classification of Liquid CrystalsClassification of Liquid Crystals Columnar Phases Cholesteric Phases Smectic Phases Nematic Phases 近晶型向列型 胆甾型 Classification of Liquid CrystalsClassification of Liquid Crystals Polymer liquid crystals (PLCs) Main-chain liquid crystal polymers (MC- LCPs) Side chain liquid crystal polymers (SC- LCPs) 9 Classification of Liquid CrystalsClassification of Liquid Crystals Mesogenic Unit ( MU 液晶基元) Main Chain (MC主链) Flexible Space (FS间隔链) (CH2)6 O O * * n O Me OO OC4H9 C4H9O O O O O (CH2)10 Si *O* n 尾接型 腰接型 back Synthesis of Side-chain Liquid Crystalline Polymer Synthesis of Side-chain Liquid Crystalline Polymer M MM M BA A B A B A M M A A B M B M AA B B M M M Mesogenic Unit Addition Polymerization 加聚反应 Polycondensation reaction 缩聚反应 Graft reaction 聚合物接枝反应 back more more Supramolecular Self-assembly of Discotic Liquid Supramolecular Self-assembly of Discotic Liquid • Synthesized by coupling PE-PEO-OH and P5T-OH using oxalyl chloride. PE-b-PEO-b-P5T (827-896-731), PDI = 1.09 C H2 C H OCH2 C H2 n2 m CH3 O O O O O O O C5H11 C5H11 C5H11 C5H11 C5H11 O O Supramolecular Self-assembly of Discotic Liquid Supramolecular Self-assembly of Discotic Liquid • Bilayer discotic liquid crystals were sandwiched between crystalline PE lamellae (TEM micrograph). • At low temperatures (< 20°C), columnar nematic phase was observed. At high temperatures (30°C < T < 95°C), discotic nematic phase was seen. Macromolecules 2005, 38, 3386-3394 PEc 5.35nm ½ PEa ½ PEOa 3.03nm P5T 3.70nm T < 20 °C 30 °C < T < 95 °C 60 ºC 5 nm-1 15 ºC 5 nm-1 向列型 7.7 Ionic Polymers7.7 Ionic Polymers 离子型聚合物 A NOVEL FABRICATION OF IONIC POLYMER-METAL COMPOSITES (IPMC) ACTUATOR WITH SILVER NANO-POWDERS A NOVEL FABRICATION OF IONIC POLYMER-METAL COMPOSITES (IPMC) ACTUATOR WITH SILVER NANO-POWDERS 10 2009/10/30 The Micro-Systems & Control Lab. 55 IntroductionIntroduction Nafion®高氟化离子交换树脂 Ag-Nafion® MembraneAg-Nafion® Membrane 2009/10/30 Multimedia & Database Lab. 56 Actuated by 3 V dc; sample moves continuously towards the anode and forms nearly a circle after 3.5 min with no sign of electrolysis Ref:Sia Nemat-Nasser,2003 Novel FabricationNovel Fabrication Overview of Artificial MuscleOverview of Artificial Muscle  There are several different types of artificial muscle and not all of it is activated by electrical voltage or current.  Electronic artificial muscle. Overview of Artificial MuscleOverview of Artificial Muscle  There are two divisions of Electro- Active Polymers (EAP): Electronic and Ionic. Each type has it’s own advantages and disadvantages.  Electronic EAPs rely on the motion of electrons as opposed to Ionic EAPs which rely on the motion of ions Some Uses for Artificial Muscle Some Uses for Artificial Muscle  Valve Controllers  Pumps  Force and Pressure sensors  Acoustic Speakers  Linear Position Actuators  Catheter 导尿管  Guide Wires 11 Principle of Operation (Electronic) Principle of Operation (Electronic)  An example of an electric EAP is the dielectric elastomer, which is a film in which thin carbon-based electrodes sandwich a soft plastic like silicone or acrylic. Actuators made of dielectric elastomers exert up to 30 times as much force, gram for gram, as human muscle. AdvantagesAdvantages  Exhibit rapid response (milliseconds)  Can hold strain under dc activation  Induces relatively large actuation forces  Exhibits high mechanical energy density  Can operate for a long time in room conditions DisadvantagesDisadvantages  Requires high voltages (~100 MV/meter). Recent development allowed for (~20 MV/meter) in the Ferroelectric EAP  Independent of the voltage polarity, it produces mostly monopolar actuation due to associated electrostriction effect. Principle of Operation (Ionic)Principle of Operation (Ionic) An example of an ionic EAP are the Ionic Polymer Metal Composites (IPMC). Teflon-like plastic soaked with lithium ions. 12V to bend the IPMC Common Types of Ionic EAPCommon Types of Ionic EAP  Carbon Nanotubes (CNT)  Conductive Polymers (CP)  Electro-Rheological Fluids (ERF)  Ionic Polymer Gels (IPG)  Ionic Polymer Metallic Composite (IPMC)