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Synthesis, thermomorphic characteristics, and fluorescent properties of poly[2,7-(9,9-dihexylfluorene)]-block-poly(N-isopropylacrylamide) -block-poly(N-hydroxyethylacrylamide) rod-coil-coil triblock copolymers

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Soft Matter 2009年第19期5卷 3761-3770页

作者： Lin, Sung-Tso Fuchise, Keita Chen, Yougen Sakai, Ryosuke Satoh, Toshifumi Kakuchi, Toyoji Chen, Wen-Chang Institute of Polymer Science and Engineering National Taiwan University Taipei 10617 Taiwan Division of Biotechnology and Macromolecular Chemistry Graduate School of Engineering Hokkaido University Sapporo 060-8628 Japan Department of Chemical Engineering National Taiwan University Taipei 10617 Taiwan

New thermoresponsive conjugated rod-coil-coil triblock copolymers were successfully synthesized from terminal azido functionalized poly(N- isopropylacrylamide)-b-poly(N-hydroxyethylacrylamide) (PNIPAAm-b-PHEAA) and alkynyl functionalized polyfluorene (PF) via a click reaction. The azido functionalized PNIPAAm-b-PHEAA copolymers with different block ratio was prepared by atom transfer radical polymerization from an initiator bearing the azide group, whereas alkynyl functionalized PF was synthesized by Suzuki coupling reaction. The lower critical solution temperature (LCST) of the block copolymers increased with an enhanced hydrophilic PHEAA block ratio, since the longer PHEAA segment facilitated the copolymer chains to stretch at an elevated temperature. The micelles of PNIPAAm-b-PHEAA with different block ratio changed into spheres, aggregate spheres, vesicles, and wormlike micelles as the temperature was increased, due to the variation on the hydrophilic/hydrophobic characteristic of PNIPAAm. However, the micellar morphologies became worms, bundles of wormlike micelles, and hollow tubes in the triblock PF-b-PNIPAAm-b-PHEAA, which were probably induced by the π-π interaction among the fluorene segments. The variation of the micelle morphology with temperature was consistent from the results of transmission electron microscopy, atomic force microscopy, and dynamic light scattering. Also, the micelle morphologies of PF-b-PNIPAAm-b-PHEAA showed a thermoreversible property based on its LCST. The photoluminescence characteristics behaved as an on/off fluorescence indicator of temperature, showing an "on-off-on" profile at an elevated temperature in water at a higher block ratio of PNIPAAm and switching to "on-off" as the block ratio of PNIPAAm decreased. The present study suggests that the PF-b-PNIPAAm-b-PHEAA copolymers have tunable morphologies and could be potentially used as thermoresponsive sensory materials. © 2009 The Royal Society of Chemistry.

关键词： Block copolymers

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Anisotropic thermal conduction in polymers subjected to uniaxial elongations

Anisotropic thermal conduction in polymers subjected to unia...

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67th Annual Technical Conference of the Society of Plastics Engineers 2009, ANTEC 2009

作者： Gupta, Sahil Camponeschi, Erin Kloppenborg, Ellen Venerus, David C. Schieber, Jay D. Department of Chemical and Biological Engineering Center of Excellence in Polymer Science and Engineering Illinois Institute of Technology Chicago IL 60616 United States

ISBN: (纸本)9781615673278

polymer processing flows involve a strong coupling of mechanical and thermal effects that have a significant impact on the final properties of the material. Simple molecular arguments suggest that Fourier's law must be generalized to allow for a tensorial thermal conductivity in polymers subjected to deformation. In our laboratory we have developed a novel, optical method to obtain quantitative measurements of anisotropic thermal diffusivity in polymers subjected to deformations. In this paper we report measurements of anisotropic thermal diffusivity and stress in both molten and solid polymers in uniaxial extension. These data are used to test the stress- thermal rule.

关键词： Thermal conductivity

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Control of thermoresponsive property of urea end-functionalized poly(n-isopropylacrylamide) based on the ydrogen bond-assisted self-assembly in water

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Journal of polymer science, Part A: polymer Chemistry 2009年第22期47卷 6259-6268页

作者： Fuchise, Keita Kakuchi, Ryohei Lin, Sung-Tso Sakai, Ryosuke Sato, Shin-Ichiro Satoh, Toshifumi Chen, Wen-Chang Kakuchi, Toyoji Division of Biotechnology and Macromolecular Chemistry Graduate School of Engineering Hokkaido University Sapporo 060-8628 Japan Institute of Polymer Science and Engineering National Taiwan University Taipei 10617 Taiwan Department of Chemical Engineering National Taiwan University Taipei 10617 Taiwan

precise synthesis and variation in the thermoresponsive property based on the supramolecular assembly of a novel urea end-functionalized poly(N-isopropylacrylamide) (PNIPAM) were studied. A series of PNIPAMs with different diphenylurea groups at the chain end (XAPhANHACOANHAPhAtrzAPNIPAM: X = H, OCH3, CH3 , NO2 , Cl, and CF3) were synthesized by using a combination of the atom transfer radical polymerization and the copper(I)-catalyzed azide-alkyne cycloaddition. The cloud point of the obtained polymers depended on the hydrogen-bonding ability of the introduced urea group. The 1H NMR measurement suggested that the obtained PNIPAM assembled in water via the intermolecular hydrogen bonding by the terminal urea group. From the dynamic light scattering and transmission electron microscopy measurements, the aggregated nanoparticles of the resulting polymer were directly observed in water at a temperature below its cloud point. The hydrogen-bonding property of the chain end urea group was concluded to be involved in the aggregation of the PNIPAM in water, leading to the variation in its cloud point. © 2009 Wiley Periodicals, Inc.

关键词： Self assembly

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Efficient bulk heterjunction solar cells based on a low-bandgap polyfluorene copolymers and fullerene derivatives

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Organic Electronics 2009年第6期10卷 1109-1115页

作者： Huang, Jen-Hsien Li, Kuang-Chieh Wei, Hung-Yu Chen, Po-Yen Lin, Lu-Yin Kekuda, Dhananjay Lin, Hong-Cheu Ho, Kuo-Chuan Chu, Chih-Wei Department of Chemical Engineering National Taiwan University Taipei Taiwan Institute of Polymer Science and Engineering National Taiwan University Taipei Taiwan Department of Materials Science and Engineering National Chiao Tung University Hsinchu Taiwan Research Center for Applied Sciences Academia Sinica Taipei Taiwan Department of Photonics National Chiao Tung University Hsinchu Taiwan

A low-bandgap polymer (PF-PThCVPTZ) consisted of fluorene and phenothiazine was designed and synthesized. With the donor-acceptor segment, the partial charge transfer can be built in the polymer backbone leading to a wide absorbance. The absorption spectrum of PF-PThCVPTZ exhibits a peak at 510 nm and an absorption onset at 645 nm in the visible range. As blended with [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) as an electron acceptor, narrow bandgap PF-PThCVPTZ as electron donor shows significant solar cell performance. Under AM 1.5 G, 100 mA/cm2 illumination, a power conversion efficiency (PCE) of 1.85% was recorded, with a short circuit current (JSC) of 5.37 mA/cm2, an open circuit voltage (VOC) of 0.80 V, and a fill factor (FF) of 43.0%. © 2009 Elsevier B.V. All rights reserved.

关键词： Butyric acid

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Synthesis and self-assembly of poly-(diethylhexyloxy-p-phenylenevinylene)- b-poly(methyl methacrylate) rod - coil block copolymers

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Macromolecules 2009年第12期42卷 4208-4219页

作者： Ho, Chun-Chih Lee, Yi-Huan Dai, Chi-An Segalman, Rachel A. Su, Wei-Fang Department of Materials Science and Engineering National Taiwan University Taipei 106 Taiwan Institute of Polymer Science and Engineering National Taiwan University Taipei 106 Taiwan Department of Chemical Engineering University of California Berkeley United States Materials Sciences Division Lawrence Berkeley National Laboratories Berkeley CA 94720 United States

A series of poly(diethylhexyloxy-p-phenylenevinylene-b-methyl methacrylate) (DEH-PPV-b-PMMA) polymers with narrow polydispersity (PDI 1H nuclear magnetic resonance (1H NMR) and gel permeation chromatography (GPC). Transmission electron microscopy (TEM) and small-angle X-ray scattering (SAXS) studies reveal the details of copolymer morphology. The DEH-PPV-b-PMM A system presented here has higher block segregation strength than many previously studied rod - coil block copolymers yet still shows experimentally accessible phase transitions with respect to temperature. As a result, this molecule offers new insight into the competition between rod - rod and rod - coil interactions that occurs in the system. The DEH-PPV rods are organized as a monolayer that is inclined with the lamellar normal (smectic C) for the copolymers containing low volume fraction of PMMA coil (

关键词： High resolution transmission electron microscopy

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Isothermal carbon dioxide sorption in poly(ionic liquid)s

Isothermal carbon dioxide sorption in poly(ionic liquid)s

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2009 AIChE Annual Meeting, 09AIChE

作者： Tang, Jianbin Shen, Youqing Radosz, Maciej Sun, Weilin Department of Chemical and Biochemical Engineering State Key Lab of Chemical Engineering Zhejiang University Hangzhou 310027 China Department of Chemical and Petroleum Engineering University of Wyoming Laramie WY 82071 United States Department of Polymer Science and Engineering Zhejiang University Hangzhou 310027 China

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Phase behavior of poly(3-alkylthiophene)/polystyrene blends

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polymer 2009年第20期50卷 4944-4949页

作者： Lee, Youngmin Kim, Jin Kon Chiu, Chu-Han Lan, Yi-Kang Huang, Ching-I. National Creative Research Initiative Center for Block Copolymer Self-Assembly Department of Chemical Engineering Polymer Research Institute San 31 Hyo-ja dong Pohang Kyungbuk 790-784 Korea Republic of Institute of Polymer Science and Engineering National Taiwan University Taipei 10617 Taiwan

Phase diagrams of blends consisting of poly(3-n-alkylthiopene) having four different n-alkyl side chain lengths (n = 4, 6, 8, 12) and polystyrene (PS) were obtained by turbidity measurement. All of the P3AT/PS blends employed in this study exhibited the upper critical solution temperature (UCST) type phase behavior. From n = 4 [poly(3-butylthipene)] to n = 6 [poly(3-hexylthipene)], the miscibility between P3AT/PS blends decreased, but with further increase in the value of n, the miscibility increased. Thus, the miscibility of the P3HT/PS blend becomes the least among four blend pairs. This interesting phase behavior depending on n was successfully illustrated via the combination of Monte Carlo simulation and molecular dynamics. © 2009 Elsevier Ltd. All rights reserved.

关键词： Solubility

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Synthesis and Characterization of Bionanoparticle-Silica Composites and Mesoporous Silica with Large Pores

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Nano Research 2009年第6期2卷 474-483页

作者： Zhongwei Niu Saswat Kabisatpathy Jinbo He LAndrew Lee Jianhua Rong Lin Yang Godfrey Sikha Branko N.Popov Todd S.Emrick Thomas P.Russell Qian Wang Department of Chemistry and Biochemistry and Nanocenter University of South CarolinaColumbiaSC 29208USA Department of Polymer Science and Engineering University of MassachusettsAmherstMA 01003USA Brookhaven National Laboratory UptonNY 11973USA Department of Chemical Engineering University of South CarolinaColumbiaSC 29208USA

A sol-gel process has been developed to incorporate bionanoparticles,such as turnip yellow mosaic virus,cowpea mosaic virus,tobacco mosaic virus,and ferritin into silica,while maintaining the integrity and morphology of the *** structures of the resulting materials were characterized by transmission electron microscopy,small angle X-ray scattering,and N2 adsorption desorption *** results show that the shape and surface morphology of the bionanoparticles are largely preserved after being embedded into *** removal of the bionanoparticles by calcination,mesoporous silica with monodisperse pores,having the shape and surface morphology of the bionanoparticles replicated inside the silica,was produced,.This study is expected to lead to both functional composite materials and mesoporous silica with structurally well-defi ned large pores.

关键词： Mesoporous silica bionanoparticles virus ferritin sol gel

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Abstracts from the 2011 Joint Annual Meeting of the Society for Northwestern Vertebrate Biology and Washington Chapter of the Wildlife Society, Held at the Wesley Inn, Gig Harbor, Washington, March 23–25, 2011

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Northwestern Naturalist 2011年第2期92卷 136-166页

作者： Michael J. Adams Christopher A. Pearl Jessica Y. Adkins Daniel D. Roby Ladd Bayliss Peter J. Loschl Donald E. Lyons Yasuko Suzuki Hannah E. Anderson Sarah T. Hamman Keith B. Aubry Catherine M. Raley John J. Rohrer Eric C. Lofroth Scott H. Fitkin Michael L. Best Hartwell H. Welsh Jamie B. Bettaso Don T. Ashton Hartwell H. Welsh Scott McBain Lindsay M. Biga Andrew R. Blaustein Susan F. Brady R. Steven Wagner Daniel J. Selski James E. Johnson R. Bruce Bury Wynn W. Cudmore Hartwell H. Welsh Nathan D. Chelgren Tara Chestnut Chaucney W. Anderson Julie Kirshtein Megan T. Cook Tiffany S. Garcia Stephen Corn Erin Muths Amanda Kissel Rick Scherer Eric Delvin Jonathan D. Bakker Peter W. Dunwiddie Diana L. Dishman Deborah A. Duffield Harriet R. Huber Dyanna M. Lambourn Karen M. Dvornich Greg Falxa Gary M. Fellers Patrick M. Kleeman David Miller Brandon Fessler Jason T. Irwin Daniel D. Beck R. Steven Wagner Marc P. Hayes John A. Frew Christian E. Grue Chris R. Friesen Robert T. Mason Stevan J. Arnold Suzanne Estes Tiffany S. Garcia Katie M. Dugger Josh Johnson Mike Rochelle A. J. Kroll Stephanie S. Gervasi Caren S. Goldberg Dan Davis Erica Bree Rosenblum Bill Bosworth Lisette P. Waits Purnima Govindarajulu Gregory A. Green Steve Negri Jennifer R. Griffiths Daniel E. Schindler Christian E. Grue Karen M. Dvornich Adam G. Hansen David A. Beauchamp Casey M. Baldwin Marc P. Hayes Gretchen Padgett-Flohr Blake R. Hossack Winsor H. Lowe Paul Stephen Corn Aaron N. Johnston Kris Kendell Dave Prescott Scott Stevens Peter M. Kiffney Carol Volk Kerensa A. King Christian E. Grue James M. Grassley Andrew J. Kroll Matt Hane Josh Johnston Mike Rochelle Stuart Farber Niels Leuthold Michael J. Adams John P. Hayes Bo Li Michael T. Brett Kent B. Livezey Ilon E. Logan Teresa J. Lorenz Kimberly A. Sullivan Amanda V. Bakian Deanna Lynch Nancy Thomas Krysten Schuler Steven Jeffries Joshua Malt Kelly R. McAllister Joanne P. Schuett-Hames Aimee P. McIntyre Jay E. Jones Eric M. Lund Frithiof T. Waterstrat Jack N. Giovanini Stephen D. Duke Marc P. Hayes US Forest Service Pacific Northwest Research Station Olympia WA 98512 kaubry@fs.fed.us US Forest Service Okanogan-Wenatchee National Forest Methow Valley Ranger District Winthrop WA 98862 British Columbia Ministry of Environment Victoria BC V8W9M1 Washington Department of Fish and Wildlife Winthrop WA 98862 Humboldt State University 1 Harpst St. Arcata CA 95521 addsmike14@*** US Forest Service Pacific Southwest Research Station 1700 Bayside Dr. Arcata CA 95521 hwelsh@fs.fed.us US Fish and Wildlife Service Arcata Field Office 1655 Heindon Road Arcata CA 95521 jamie_bettaso@fws.gov Redwood Sciences Laboratory US Forest Service1700 Bayview Drive Arcata CA 99521 dashton@fs.fed.us hwelsh@fs.fed.us McBain &amp Trush 980 7th Street Arcata CA 95521 scott@*** Oregon State University Environmental Sciences Graduate Program Corvallis OR 97331 lindsay.biga@science.oregonstate.edu Oregon State University Department of Zoology Corvallis OR 97331 US Geological Survey Forest and Rangeland Ecosystem Science Center 3200 SW Jefferson Way Corvallis OR 97331 buryb@usgs.gov Life Science Department Chemeketa Community College Salem OR 97309 wynn.cudmore@chemeketa.edu US Forest Service Redwood Sciences Laboratory 1700 Bayview Drive Arcata CA 95521 hwelsh@fs.fed.us USGS Oregon Water Science Center 2130 SW 5th Avenue Portland OR 97207 chestnut@usgs.gov USGS Headquarters 12201 Sunrise Valley Drive Reston VA 20192 US Geological Survey Northern Rocky Mountain Science Center Aldo Leopold Wilderness Research Institute 790 E. Beckwith Avenue Missoula MT 59801 scorn@usgs.gov US Geological Survey Fort Collins Science Center 2150 Centre Avenue Building C Fort Collins CO 80526 Department of Biological Sciences Simon Fraser University Burnaby BC V5A 1S6 Colorado State University Department of Fishery and Wildlife Biology Fort Collins CO 80523 The Nature Conservancy 120 Union Ave SE Olympia WA 98501 edelvin@tnc.org School of Forest Resources University of Washington Seattle WA

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Incorporation of a stable radical 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) in an electrochromic device

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Solar Energy Materials and Solar Cells 2009年第12期93卷 2102-2107页

作者： Hu, Chih-Wei Lee, Kun-Mu Huang, Jen-Hsien Hsu, Chih-Yu Kuo, Tsung-Hsien Yang, Dung-Jing Ho, Kuo-Chuan Institute of Polymer Science and Engineering National Taiwan University Taipei 10617 Taiwan Photovoltaics Technology Center Industrial Technology Research Institute Chutung Hsinchu 31040 Taiwan Department of Chemical Engineering National Taiwan University Taipei 10617 Taiwan

A stable organic radical, 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO), was studied. We employed TEMPO as a cathodic radical provider in propylene carbonate (PC) and poly(3,4-propylenedioxythiophene) derivatives (PProDOT-Et2) as an anodic electrochromic (EC) thin film, which was obtained through electropolymerization. On assembling them together in a device, the electrochemical and optical performances of this hybrid electrochromic device (ECD) showed reversible cycling stability and high absorbance attenuation in the visible range. By selecting proper electrolytes (LiClO4/PC) and controlling the deposited charge of the PProDOT-Et2 thin film, it was possible to obtain a transmittance change (ΔT) of up to 59% at 590 nm with no noticeable degradation after operating between 0 and 0.9 V for 1000 cycles. Furthermore, an electrochemical quartz crystal microbalance (EQCM) was used to investigate ion migrations in the PProDOT-Et2 thin film, which influenced its long-term stability. © 2009 Elsevier B.V. All rights reserved.

关键词： Thin films

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