- Selective alteration of polymer surfaces by thermal cleavage of fluorinated side chains
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We have synthesized a series of fluorinated side chain block copolymers based on either a hydroborated polystyrene-b-polyisoprene or a poly(methyl methacrylate)-b-poly(2-hydroxyethyl methacrylate) backbone. Through polymer-analogous reactions, perfluorinated ester, fluorinated urethane, and fluorinated carbonate side chains were attached to the pendant hydroxyl groups. Their selective thermal degradation behavior was investigated using thermogravimetric analysis (TGA) and thermal desorption mass spectrometry (TDMS). In addition, we investigated the heat- and laser-induced selective alteration of polymer film surfaces by chemically highly selective cleavage of the fluorinated side chains using X-ray photoelectron spectroscopy (XPS), FT-infrared spectroscopy (FT-IR), and contact angle measurements. Finally, we demonstrate the potential to create a laterally patterned surface with different regions of chemically well-defined surface moieties from our fluorinated block copolymers by a dry laser process.
- Boeker, Alexander,Herweg, Thomas,Reihs, Karsten
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- In Situ Generated Janus Fabrics for the Rapid and Efficient Separation of Oil from Oil-in-Water Emulsions
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A cotton fabric was coated with a polymer that contains both poly(dimethyl siloxane) (PDMS) and poly(N,N-dimethylaminoethyl methacrylate) (PDMAEMA). When the repeat unit number of PDMS is about three-fold that of PDMAEMA and the fabric is exposed to air, the fabric is superhydrophobic because PDMS in the coating covers the PDMAEMA chains. Upon contact with an oil-in-water emulsion, the water-soluble PDMAEMA rises to the top and the side in contact with the emulsion becomes hydrophilic. The emerged PDMAEMA chains then cause the emulsion droplets to coagulate, and the aggregated oil fills the pores on the superhydrophobic side of the fabric. The oil-impregnated side remains hydrophobic even upon prolonged contact with water. Thus, a Janus fabric is elegantly generated in situ and sustained. This easy-to-prepare Janus fabric rapidly and efficiently separates oil from emulsions and may find practical applications.
- Wang, Zijie,Liu, Guojun,Huang, Shuaishuai
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supporting information
p. 14610 - 14613
(2016/11/23)
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- Synthesis and characterization of some organosilicon derivatives of poly 2-hydroxyethyl methacrylate with cubane as a cross-linking agent
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Some silyl ether derivatives of 2-hydroxyethyl methacrylate (HEMA) were prepared. The Et3Si, Ph3Si and Me3Si groups together with cubane-1,4-dicarboxylic acid (CDA) were covalently linked with HEMA. The silyl-linked HEMA are abbreviated as TETMA, TPhMA and TMEMA, respectively. CDA linked to two HEMA groups is the cross-linking agent (CA). Free radical copolymerization and cross-linking copolymerization of the resulting monomers with 2-hydroxyethyl methacrylate (HEMA) with the various ratios of CA as cross-linking agent, were carried out using AIBN as initiator at the temperature ranges 60-70 °C. The cross-linking copolymers were identified by FT-IR spectroscopy. The glass transition temperature (T g) of the network polymers was determined calorimetrically. The Tg of network polymers increases with increase of cross-linking degree. All monomers and polymers were identified by spectroscopic methods. These silyl derivatives modified methacrylate polymer properties.
- Assadi, Mohammad G.,Mahkam, Mehrdad,Tajrezaiy, Zohreh
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p. 4755 - 4760
(2007/10/03)
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- Copolymerization of Acrylonitrile with trimethyl Silanes
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Acrylonitrile (AN) was copolymerized with trimethylsilane (2-MAETMS) and trimethylsilane (2-MAPTMS) in dimethylformamide and dimethylsulfoxide at temperatures between 50 deg C and 70 deg C using azobisisobutyronitrile (AIBN) as initiator.The copolymer composition was determined by silicon estimation and reactivity ratios were calculated by the Kelen-Tudos method.In both the systems, r1(AN) and r2(2-MAETMS/2-MAPTMS) are higher in DMF compared to the values in DMSO.Arrhenius parameters were derived for AN-2-MAETMS system.The difference between the activation energies (E11 - E12) favour self-propagation for the acrylonitrile radical, whereas A11/A12 favours cross-propagation.In case of 2-MAETMS radical, E22 - E21 favours cross-propagation but A22/A21 favours self-propagation.The influence of the comonomers on some of the basic properties of copolymers like solubility, intrinsic viscosity, softening and glass transitions have also been studied.
- Bajaj, P.,Gupta, D. C.
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p. 228 - 234
(2007/10/02)
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