Co-reporter:Yu Liu;Xiaochuan Shui;Meng Wang;Chenguang Zhang;Yuechuan Wang
Polymer Chemistry (2010-Present) 2017 vol. 8(Issue 15) pp:2363-2369
Publication Date(Web):2017/04/11
DOI:10.1039/C6PY02104B
The radical polymerization of acetylene-bearing acrylates to linear clickable polymers represents a synthetic challenge because acetylenes are too reactive to avoid chain branching or cross-linking. Herein, we report a methodology for the synthesis of acetylene-functionalized clickable polymers via conventional free radical polymerization of a novel acrylate bearing tertiary acetylene, 1-ethynylcyclohexyl acrylate (ECA). This methodology allows the acetylene-functionalized polymers to be prepared by conventional free radical polymerizations without the need to protect the acetylene group before polymerization and without the help of an ATRP/RAFT agent. The characteristics of ECA in free radical polymerization and copolymerization including bulk polymerization and conventional solution polymerization at varied concentrations and reaction times were studied. High molecular weight acetylene-functionalized polymers were prepared and were characterized by SEC, 1H-NMR, FTIR and DSC. When ECA was coploymerized with methyl acrylate, as the feed ratio of ECA increased, the rate of the polymerization reaction and the molecular weight of the copolymer decreased while the molecular weight distribution (PDI) slightly increased. The glass transition temperature of PECA was found to be 110 °C by DSC. The acetylene-decorated polymer chains are thermally cross-linkable and photochemically thiol–yne clickable.
Co-reporter:Xiaohang Zeng, Yanqiong Ma, Yuechuan Wang
Applied Surface Science 2015 Volume 338() pp:190-196
Publication Date(Web):30 May 2015
DOI:10.1016/j.apsusc.2015.02.134
Highlights
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In this paper we report an exploring to enhance the performance and stability of low energy surface on polyurethane network with a fluorinated block copolymer.
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The fluorinated crystalline blocks aggregate into a shell to protect the surface from rearrangement and hydrolysis when in contact with water, whilst the soft polyester block in the block copolymer provides the required flexibility for fluorinated components to segregate to the surface.
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The functionalized surfaces by this way are highly hydrophobic and exhibited better hydrophobic stability.
Co-reporter:Shijian Tu;Yuechuan Wang;Jianwu Lan;Qingkang Zheng;Jian Wei;Sheng Chen
Journal of Applied Polymer Science 2012 Volume 124( Issue 3) pp:2625-2631
Publication Date(Web):
DOI:10.1002/app.35296
Abstract
Monoalkoxysubstituted and dialkoxysubstitued thiophene monomers were synthesized by the nucleophilic substitution and transetherification reactions. Electrochemical homopolymerization of 3-octyloxythiophene (OOT) and 3,4-dioctyloxythiophene (DOOT), copolymerization of OOT with DOOT were performed via potentiodynamic and potentiostatic methods in the supporting electrolyte. Both the copolymer and homopolymers were characterized via cyclic voltammetry, scanning electron microscopy, gel permeation chromatography, and spectroelectrochemical analysis. In the redox process of the polymers, it was linear relationship between the peak current and the scanning rate in their cyclic voltammograms. The copolymer of P(OOT-co-DOOT) showed obvious change of color between red and bright blue in reduced and oxidized states, that has a great difference with the homopolymers. The morphology studies indicated that the electrochemical deposition of P(OOT-co-DOOT) proceeds via a mechanism of nucleation and two-dimensional growth. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Co-reporter:Hao Jiang, Weizhou Zhao, Chaolong Li and Yuechuan Wang
Soft Matter 2011 vol. 7(Issue 6) pp:2817-2824
Publication Date(Web):31 Jan 2011
DOI:10.1039/C0SM01174F
Porosity in efficiently packed nanoparticle films is limited. A process modifying particle film to introduce extra pores in self-assembled nanoparticle film is needed. We report here a method by the selective dissolution of sacrificial particles from the codeposited binary latex-particle film for the preparation of nanoporous film with designable porosity. Nanoporous films with porosity and refractive index tunable in the range of 33–86% and 1.37–1.07, respectively, on a poly(methyl methacrylate) (PMMA) substrate are prepared by spin-casting PMMA/polystyrene (PS) mixed latexes and selective removal of PS particles with cyclohexane after thermally treating the deposited particle film to enhance the adhesion on PMMA substrate. The nanoporous film on PMMA substrate prepared with PMMA/PS latexes in 1/1 weight ratio under the optimal condition exhibited ultra low reflectance of ∼0.02%. With smaller sized latex particles (25 nm and 22 nm for PMMA and PS, respectively), smooth nanoporous film on PMMA substrate with 99.95% of transmittance was prepared. The nanoporous structures on PMMA substrate are stable toward ultrasonic cleaning in water and resist to peeling with Scotch tape.
Co-reporter:Li-ping Gao, Guo-jing Ding, Yue-chuan Wang, Yu-lin Yang
Applied Surface Science 2011 Volume 258(Issue 3) pp:1184-1191
Publication Date(Web):15 November 2011
DOI:10.1016/j.apsusc.2011.09.068
Abstract
Polyether urethane diacrylate matrix (PEUDA) and acrylate-functional viologen (ACV2+) were successfully synthesized and characterized in detail by FTIR and 1H NMR spectra, respectively. Subsequently, they were used to prepare UV curing crosslinked polyviologen film in combination with 2-hydroxyethyl methacrylate (HEMA), trimethylolpropane ethoxylate triacrylate (TMPTA) and diphenyl (2, 4, 6-trimethylbenzoyl) phosphine oxide (TPO). UV curing approach confined the polyviologen film on ITO electrode, which imparted the film excellent adhesion ability to ITO glass, good solvent resistance, excellent chemical stability, excellent optical and electrochemical properties. The crosslinked PACV2+ film exhibited excellent photochromic and electrochromic performances. After UV illumination for 60 s, the crosslinked PACV2+ film can swiftly change its color from pale yellow to deep blue, while the optical transmission of crosslinked PACV2+ film at 610 nm did not change significantly and still retained about 63.6% after 30 cycles. Simultaneously, the cyclic voltammetry experiment showed the PACV2+ film can undergo repeatable electrochemical redox reactions with good reversibility beyond the 10th scan. Furthermore, the electrochromic device composed of the PACV2+ film and gel electrolyte film can undergo reversible color change in response to the external voltages of −2.0 V and 2.0 V, respectively, while the contrast of EC device at 610 nm did not change significantly and still retained about 39.5% after 10 cycles. This UV curing approach to preparing viologen-functional film offers a method to preparing large-scale photo- and electrochromic device, which is relatively simple, high productivity, energy saving, and environmental protection.
Co-reporter:Hao Jiang, Weizhou Zhao, Chaolong Li, Yuechuan Wang
Polymer 2011 Volume 52(Issue 3) pp:778-785
Publication Date(Web):3 February 2011
DOI:10.1016/j.polymer.2010.12.036
Increased using of plastic optical elements has generated a need for applying antireflection coatings onto plastic substrates. In this paper we reported a facile method to preparing porous thin films on plastic substrates by spin-casting poly (methyl methacrylate) (PMMA)/polystyrene (PS) mixed latices, followed by selectively removing PS particles. The refractive index of the porous coating is directly related to its porosity which could be controlled by varying mixing fraction of the sacrificial PS particles. The obtained porous thin films exhibited excellent anti-reflective (AR) performance over visible range with minimum reflection of 0.02%. The powerful control on refractive index and the versatility of this method makes it practicable to prepare antireflective coating on various plastic substrates with optimal performance.
Co-reporter:Chaolong Li, Hao Jiang, Yu Wang, Yuechuan Wang
Polymer 2011 Volume 52(Issue 2) pp:376-382
Publication Date(Web):21 January 2011
DOI:10.1016/j.polymer.2010.11.050
Miniemulsion polymerization is most suitable for the targeted synthesis of vinyl copolymers than the conventional emulsion polymerization, because in miniemulsion polymerization each monomer nanodroplet is a nanoreactor, and the monomers in each droplet are in situ converted to the corresponding polymers. Soluble and hyperbranched poly(methyl methacrylate)s (PMMA) were prepared with quantitative monomer conversion and without gelation by the miniemulsion copolymerization with di- and tri-acrylate and mediated with 1-dodecyl thiol (DDT). DDT acted both as a gelation prohibitor and as a reactive cosurfactant. The PMMAs with varied “X” or “Ж” shaped branches, depending on the di- and tri-functional acrylate used as the branching agent, are characterized and interpreted in terms of the repeating units per part, parts and branches per macromolecule, average molecular weight, latex particle size and size distribution. Effects of topology changes of the branched PMMAs on the rheological behaviors are observed for the first time: from Newtonian flow for the densely branched PMMAs to the non-Newtonian flow with pronounced shear thickening for the PMMA samples with high-molecular-weight and longer parts.
Co-reporter:Liang-cheng Cao, Miao Mou and Yuechuan Wang
Journal of Materials Chemistry A 2009 vol. 19(Issue 21) pp:3412-3418
Publication Date(Web):14 Apr 2009
DOI:10.1039/B818523A
Covalently bonding viologen groups at the chain-ends of hyperbranched polyglycerol would enhance the performance of viologen chromophores to external photo- and potential stimuli, because the amorphous, soft and hyperbranched polyether in globular conformation inhibits the aggregation or crystallization of the highly concentrated and ionic viologen chromophores, and also stabilizes the viologen cation radicals. Hyperbranched and functional polyglycerol containing viologen chromophores (HPG-V2+) are prepared by firstly capping the terminal hydroxyl groups of hyperbranched polyglycidol (HPG) with chloroacetyl, and then with the chloroacetyl groups and 4,4′-bipyridine to form the viologen chromophores on the chain-ends of HPG. The evolution of chemical structures from glycidols to HPG-V2+ is carefully characterized. The HPG-V2+ exhibits both photo- and electrochromism with high color contrast, short response time, and well stability: upon UV irradiation, the HPG-V2+ film changes its color from pale yellow to purple, while optical transmittance at 540 nm decreases from ≥90% to <10%; to the stimuli of pulsed 2.5 V electrical potential, the solution type electrochromic cell based on HPG-V2+ responds with reversible color changes from transparent to violet within about 0.52 s, much faster than the previously reported viologen-containing electrochromic polymers. The photochromism of HPG-V2+ is effective even in atmosphere by sunshine: when exposing to sunshine for several minutes the color of the HPG-V2+ film turned to purple, while low molecular weight viologen analogue exhibits only electrochromism.
Co-reporter:Liang-cheng Cao, Miao Mou, Gang Feng, Yue-chuan Wang
European Polymer Journal 2009 Volume 45(Issue 9) pp:2587-2593
Publication Date(Web):September 2009
DOI:10.1016/j.eurpolymj.2009.06.015
Thermally reversible light scattering (TRLS) films are prepared from ultraviolet (UV) curing of polyether urethane diacrylate (PEUDA) with dispersed low molecular weight 1-octadecanol (OD). Depending on the temperature, the OD domains are crystalline or amorphous and this produce opaque or transparent films in a reversible way. Stable optically transparent and light scattering states are obtained after 100 successive heating–cooling cycles. Moreover, morphologies of the OD domains could be varied significantly with the cure temperature and this led to notable discrepancy in optical properties. By using an UV-mask and curing in two steps at different temperatures, complex patterns could be recorded in the film that were encoded at high temperatures (60 °C) and revealed at low temperatures (i.e., at room temperature), which makes the film a candidate for thermo-optical recording medium.A novel thermo-optical material composed of polyether urethane diacrylate with dispersed octadecanol is prepared by UV curing method for applications as thermally reversible light scattering (TRLS) films and thermo-optical recording medium.
Co-reporter:Chen Sheng;Bao Wenting;Tu Shijian ;Wang Yuechuan
Journal of Applied Polymer Science 2008 Volume 109( Issue 1) pp:120-125
Publication Date(Web):
DOI:10.1002/app.27604
Abstract
Poly(3-n-octyloxythiophene), a conjugated polymer, which possessed solubility in common organic solvents, was synthesized by electrochemical polymerization in the presence of lithium perchlorate as the supporting electrolyte and sodium dodecyl sulfate as the surfactant in an aqueous medium. Characterizations of the intermediate, monomer, and polymer were performed by NMR spectroscopy, Fourier transform infrared spectroscopy, ultraviolet–visible spectroscopy, and gel permeation chromatography. The process of electrochemical polymerization and the electrochemical redox behaviors were investigated by cyclic voltammetry and the potentiostatic method. A poly(3-n-octyloxythiophene) film that was deposited on a platinum electrode was found to exhibit electrochromic behaviors, and it switched electrochemically between blue–green oxidized and dark red reduced states. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Co-reporter:Zhendong Zhu, Luo Kai, Yuechuan Wang
Materials Chemistry and Physics 2006 Volume 96(2–3) pp:447-453
Publication Date(Web):10 April 2006
DOI:10.1016/j.matchemphys.2005.07.067
Hyperbranched polyester-encapsulated crystals of silver nanoparticles with size in 3–19 nm, average 7.7 ± 0.5 nm, were prepared by ultraviolet irradiation of silver ions with the assistance of hyperbranched polyesters terminated by –OH and –COOH groups and aliphatic phosphate surfactant. The silver nanoparticles were characterized by transmission electron microscopy, selected area electron diffraction, UV–vis spectra, X-ray diffraction, X-ray photoelectron spectra and Fourier transform infrared spectroscopy. Controlled and comparing experiments showed that non-aggregated silver nanoparticles could not be synthesized without the using of either hyperbranched polyester and aliphatic phosphate surfactant, indicating the importance of hyperbranched polyester and phosphate surfactant in stabilizing silver nanoparticles during the photoreduction.
Co-reporter:Tao Wan;Fei Feng
Journal of Applied Polymer Science 2006 Volume 102(Issue 6) pp:5105-5112
Publication Date(Web):28 SEP 2006
DOI:10.1002/app.24166
UV-curable, transparent acrylic resin/titania organic–inorganic hybrid films were prepared by controlled hydrolysis of titanium tetrabutoxide in Span-85/Tween 80 reverse micelles and the subsequent in situ photopolymerization of the acrylic monomers. UV–vis spectra and atomic force microscopy (AFM) indicated the presence of a nanoscale hybrid composition. The onset of absorption (λonset) of titania in the hybrids appeared between 363.4 and 383.5 nm, which exhibited blue shifts relative to that of bulk anatase (λonset = 385 nm). The titania content increased rapidly at higher temperature and higher TTB content, whereas it increased slowly with longer post-thermal treatment times. The refractive index and UV shielding properties of the organic polymer were obviously improved with increasing titania content. AFM images showed the inorganic domains (mean size 25.3–28.8 nm) were uniformly dispersed in the polymeric networks. The roughness parameters of the hybrid material were: toughness, 1.5–2.3 nm; root mean square roughness, 4.5–4.6 nm; and peak and valley distance, 9.7–19.4 nm. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5105–5112, 2006
Co-reporter:Liang-cheng Cao, Miao Mou and Yuechuan Wang
Journal of Materials Chemistry A 2009 - vol. 19(Issue 21) pp:NaN3418-3418
Publication Date(Web):2009/04/14
DOI:10.1039/B818523A
Covalently bonding viologen groups at the chain-ends of hyperbranched polyglycerol would enhance the performance of viologen chromophores to external photo- and potential stimuli, because the amorphous, soft and hyperbranched polyether in globular conformation inhibits the aggregation or crystallization of the highly concentrated and ionic viologen chromophores, and also stabilizes the viologen cation radicals. Hyperbranched and functional polyglycerol containing viologen chromophores (HPG-V2+) are prepared by firstly capping the terminal hydroxyl groups of hyperbranched polyglycidol (HPG) with chloroacetyl, and then with the chloroacetyl groups and 4,4′-bipyridine to form the viologen chromophores on the chain-ends of HPG. The evolution of chemical structures from glycidols to HPG-V2+ is carefully characterized. The HPG-V2+ exhibits both photo- and electrochromism with high color contrast, short response time, and well stability: upon UV irradiation, the HPG-V2+ film changes its color from pale yellow to purple, while optical transmittance at 540 nm decreases from ≥90% to <10%; to the stimuli of pulsed 2.5 V electrical potential, the solution type electrochromic cell based on HPG-V2+ responds with reversible color changes from transparent to violet within about 0.52 s, much faster than the previously reported viologen-containing electrochromic polymers. The photochromism of HPG-V2+ is effective even in atmosphere by sunshine: when exposing to sunshine for several minutes the color of the HPG-V2+ film turned to purple, while low molecular weight viologen analogue exhibits only electrochromism.
