功能高分子材料 (3)

功能高分子材料功能高分子材料 3 3 xxWILEY VCH VerlagGmbHc water CAofthePNIPAAm cottonfabricat23and40 C Inset imagesofthe dropletsat therespective temperatures d Differen tial scanningcalorimetry DSC thermogram showingtheLCSTphase transitionin continuouscycles e watercollection superhydrophilic state by hydrogenbonding betweenPNIPAAm andf waterrelease superhydrophobic state bytheformation ofPNIPAAm intermolecularbonds Adv Mater xx DOI 10 1002 adma xx042785 advmat de MaterialsViews wileyonlinelibrary xxWILEY VCH VerlagGmbH Co KGaA WeinheimMUNICATION J BB6L The authorsthank ShufangLu andXiaolin Hefor drawingFigure3e Received October14 xxRevised November23 xxP ublished online 1 A R Parker C R Lawrence Naturexx 414 33 2 W J Ha milton M K Seely Nature1976 262 284 3 Y Zheng H Bai Z Huan g X Tian F Q Nie Y Zhao J Zhai L Jiang Naturexx 463 640 4 H Bai X Tia n Y Zheng J Ju Y Zhao L Jiang Adv Mater xx 22 5521 5 H Don g N Wang L Wang H Bai J Wu Y M Zheng Y Zhao L Jiang Chem Ph ys Chem xx 13 1153 6 X L Tian Y Chen Y M Zheng H Bai L Jia ng Adv Mater xx 23 5486 7 E Kang G S Jeong Y Y Choi K H Le e A Khademhosseini S H Lee Nature Mater xx 10 877 8 M Lewin Handbook offiberchemistry CRC Press New Yorkxx 9 B Singh M Gupta A Verma O S Tyagi Polym Int 2000 49 1444 10 V R Botaro A Gandini M N Belgacem J Thermoplast Compos xx 18 107 11 A Carlmark E Malmstrom J Am Chem Soc xx 124 900 12 A Carlmark E E Malmstrom Biomacromoleculesxx 4 1740 13 J Lindqvist D Nystrom E Ostmark P Antoni A Carl mark M Johansson A Hult E Malmstrom Biomacromoleculesxx 9 2 139 14 Y Y Kong Y Y Liu J H Xin J Mater Chem xx 21 17978 15 Y Ono T Shikata J Am Chem Soc xx 128 10030 16 H G Schil d Prog Polym Sci 1992 17 163 17 A C C Esteves L Bombalski T Trindade K Matyjaszewski A Barros Timmons Smallxx 3 1230 18 X Z Zhang Y Y Yang F J Wang T S Chung Langmuirxx 18 xx 19 A B D Cassie S Baxter Trans Fara day Soc 1944 40 546 20 A Tuteja W Choi M L Ma J M Mabry S A Ma zzella G C Rutledge G H McKinley R E Cohen Sciencexx 318 16 18 21 A Marmur Langmuirxx 19 8343 22 H G Schild D A Tirre ll J Phys Chem 1990 94 4352 23 E C Cho J Lee K Cho Macromo leculesxx 36 9929 24 R N Wenzel Ind Eng Chem 1936 28 988 25 T L Sun G J Wang L Feng B Q Liu Y M Ma L Jiang D B Zhu A ngew Chem Int Ed xx 43 357 26 B X Leng Z Z Shao G deWith W H Ming Langmuirxx 25 2456 27 Q Fu G V R Rao S B Basame D J Keller K Artyushkova J E Fulghum G P Lopez J Am Chem Soc xx 126 8904 28 K N Plunkett X Zhu J S Moore D E Leckband L angmuirxx 22 4259 consecutively rinsedwithwater acetone andethanol Next the bare cotton wasimmersed indistilled waterand leftinanultrasonic bathfor5min This procedurewas repeatedthree timesafter whichthebarecotton wasdried at40 C under vacuum for24hours The driedbare cotton wasthen pre treated withUV Ozone irradiationfor about10min oneach sideofthefabric Next itwasimmersed ina solutioncontaining15mL ofdry tetrahydrofuran THF a catalyticamount of4 dimethylamino pyridine DMAP and triethylamine TEA 0 203mL Finally BiB 0 17mL was addedinto themixture The reactionwas kept atroom temperature for12hours undera mildArgon flow bubblingintothesolution The product BiB cotton was rinsedthoroughly andconsecutively for3times withTHF acetone andwater and finally driedat40 C undervacuum for24hours Grafting ofN Isopropylacrylamide fromthe initiator functionalized cottonfabric The initiator modif ied cottonfabric BiB cotton 0 0314g CuBr 0 0145mg 0 101mmol N isopropylacrylamide NIPAAm1 141g 10 1mmol and pentamethyldiethyleriamine PMDETA21 L 0 101mmol were addedinto aSchlenk fl ask containinga MeOH H2O solution 3 1v v 4mL previously deoxygenatedby anArgon flow The solution was frozenby liquidnitrogen sequentiallydegassed bythree freeze vaum Argon thaw cycles to remove the oxygenfromthesystem After thesecycles the Schlenkflaskwas sealedand thesolutionwaskeptatroomtemperaturewith slowmagicstirringfor24hours After thisperiod thefabricwas sequentiallywashed withmethanol ethanol andwater to removetheresidual monomersand catalyst plex The PNIPAAmmodif ied fabric PNIPAAm cotton was finally dried undervacuum at40 C overnight Extended purificationprocedure The PNIPAAm cottonfabricfabricwasSoxhlet extractedinamethanol refl ux 200mL during1hour toremovethe non reacted monomerresidues thepolymerabsorbed atthesurface i e not covalentlybonded andtheremaining Cu catalystplex After theextraction thefabricwasdriedundervacuumat40 C overnight This sample denominated as prepared dryPNIPAAm cottonfabric was usedfor allthe experimentsreported here The extractionsolutions andwashing solventfractions werecollected andevaporated ina rotavaptocollectthe solidfractions forfurther characterization see SI Supporting InformationSupporting Informationandavideo showingthewatercollection andrelease behaviourare availablefromtheWiley OnlineLibrary orfr