NarendraReddy,WenlongZhou,MingboMa Keratin-BasedMaterials Also of interest SustainabilityofPolymericMaterials ValentinaMarturano,VeronicaAmbrogi,PierfrancescoCerruti, ISBN----,e-ISBN---- SuperabsorbentPolymers. ChemicalDesign,ProcessingandApplications SandraVanVlierberghe,ArnMignon, ISBN----,e-ISBN---- IndustrialBiotechnology MarkAnthonyBenvenuto, ISBN----,e-ISBN---- Biosensors. FundamentalsandApplications ChandraMouliPandey,BansiDharMalotra, ISBN----,e-ISBN---- BiomimeticNanotechnology. SensesandMovement AnjaMueller, ISBN----,e-ISBN---- Narendra Reddy, Wenlong Zhou, Mingbo Ma Keratin-Based Materials Authors Dr.NarendraReddy Dr.MingboMa CentreforIncubation DepartmentofTextilesandMaterials Innovation,ResearchandConsultancy Engineering JyothyInstituteofTechnology ZhejiangSci-TechUniversity ThataguniPost 310018Hangzhou Bengaluru560082 China India [email protected] [email protected] Dr.WenlongZhou DepartmentofTextilesandMaterials Engineering ZhejiangSci-TechUniversity 310018Hangzhou China [email protected] ISBN978-1-5015-1913-0 e-ISBN(PDF)978-1-5015-1176-9 e-ISBN(EPUB)978-1-5015-1187-5 LibraryofCongressControlNumber:2020940495 BibliographicinformationpublishedbytheDeutscheNationalbibliothek TheDeutscheNationalbibliothekliststhispublicationintheDeutscheNationalbibliografie; detailedbibliographicdataareavailableontheInternetathttp://dnb.dnb.de. ©2020WalterdeGruyterGmbH,Berlin/Boston Coverimage:Molekuul/iStock/GettyImagesPlus Typesetting:IntegraSoftwareServicesPvt.Ltd. Printingandbinding:CPIbooksGmbH,Leck www.degruyter.com Preface Keratinisundoubtedlyoneofnature’shighlysophisticated,uniqueandversatilema- terials. From the hollow honeycombs and hierarchical structure in feathers that pro- videlowdensity,theexcellentthermalandacousticresistancesofwool,extraordinary toughness of some mammalian scales and flexibility and diversity of human hairs, keratinshaveuniquestructureandproperties.Keratinshavespecificpeptidesequen- cesthatcanpromotecellattachmentandgrowthandarepreferredformedicalappli- cations. Keratins can be made into fibers, films, freeze-dried scaffolds, micro- and nanoparticles.Conventionally,keratinfromwoolistheonlysourceexploitedforcom- mercial applications. In addition to wool, other sources of keratin such as poultry feathersareavailableinlargequantitiesandatconsiderablylowcostbutarenoteffec- tivelyutilizedandaremostlydisposedaswaste.Realizingtheimportanceofkeratin, technologies have been developed to extract keratin from feathers, wool and other sources.Studieshavealsoprovidedbetterinsightsintothestructureandpropertiesof keratinandhaveenableddevelopingnewertechnologiesforextractionofkeratinand converting the keratin into biomaterials for various applications. Keratin has been found to be suitable for environmental remediation, biotechnology, medicine, elec- tronics,cosmeticsandmanyotherapplications.Inthisbook,wepresentthestructure, properties, processability and applications of keratin. Initial chapters discuss on the properties and processing of various sources of keratins. Later, we have divided the chapters based on the formsof keratin. The last chapter reportsthe recent and most uniqueapplicationsofkeratin.Everyefforthasbeenmadetoprovidecomprehensive information in each section. However, the contents in this book are mostly designed togiveanoverviewofthekeratinanditspropertiesandapplications,andreadersare urgedtorefertotheoriginalreportsforcomprehensiveinformationonspecifictopics. https://doi.org/10.1515/9781501511769-202 Contents Preface V Chapter1 Introductiontokeratin 1 1.1 Generalclassificationandpropertiesofkeratin 3 1.2 Structureandpropertiesofhumanhairkeratin 4 1.3 Woolkeratin 9 1.4 Keratinsinhorns 17 1.5 Keratininmarineanimals 20 1.6 Keratininpangolinscales 24 Chapter2 Extractionofkeratin 25 2.1 Extractionofkeratinusingalkaliwithorwithoutreducingagents 25 2.2 Ionicliquidsforkeratinextraction 30 2.3 Enzymaticextractionofkeratin 43 2.4 Microwave-assistedkeratinextraction 48 2.5 Steamflashexplosion 48 2.6 Extractionofkeratinfromhornandhoofs 50 2.7 Keratinobtainedusingeutecticsolventsystem 51 2.8 Pretreatment/oxidationofkeratinmaterials 53 Chapter3 Applicationsofkeratinhydrolysates 55 3.1 Degradationofkeratinusingbacteriaandfungi 55 3.2 Treatingkeratinforconversionintoanimalfeed 61 3.3 Biofuelfromkeratin 66 3.4 Bacterialdegradationofkeratin 67 3.5 Fungalstrainsusedforkeratinextraction 71 Chapter4 Films/membranesfromkeratinandtheirapplications 74 4.1 Purekeratinfilms 74 4.2 Cross-linkingkeratinfilms 82 4.3 Blendsofkeratinwithotherbiopolymers 86 4.4 Keratinfilmswithsyntheticpolymerblends 98 4.5 Thermoplasticfeatherfilms 106 VIII Contents Chapter5 Keratinmadeintogels 109 5.1 Hydrogels,aerogelsandnanogelsfromfeatherkeratin 109 5.2 Hydrogelsfromwoolkeratin 113 5.3 Woolkeratinforhydrogels 121 5.4 Hydrogelsfromhumanhair 122 5.5 Formationofhydrogelsthroughoxidation 123 5.6 Hemostaticwounddressings 128 5.7 Nanogelsandaerogels 132 Chapter6 Keratinforenvironmentalremediation 135 6.1 Wool 141 6.2 Keratinassorbentfordyes 144 6.3 Sorptionofoil 147 Chapter7 Biocomposites 148 7.1 Compositesusingwoolfibers/woolkeratin 153 7.2 Compositesfromhornkeratin 158 Chapter8 Fibersfromkeratin 160 8.1 Normal(microfibers) 160 8.2 Keratinnanofibers 163 Chapter9 Keratinmicro/nanoparticles 174 Chapter10 Miscellaneousapplicationsofkeratin 187 10.1 Cosmeticapplicationsofkeratin 187 10.2 Flameretardants 187 10.3 Supercapacitors 190 10.4 Finishingofwooltextiles 193 10.5 Microbialfuelcell 195 10.6 Substitutesfornailplates 197 10.7 Keratinasfertilizer 198 10.8 Scaffoldsfortissueengineering 199 10.9 Devicesandelectronicapplications 199 Contents IX 10.10 Electronicskin 204 10.11 Detectionofchemicals,metalsandbioentities 205 References 213 Index 229