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Solution-grown aligned crystals of diketopyrrolopyrroles(DPP)-based small molecules:Rough surfaces and relatively low charge mobility

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Chinese Chemical Letters 2016年第4期27卷 523-526页

作者： Zhuo-Ting Huang Cong-Cheng Fan Guo-Biao Xue Jia-Ke Wu Shuang Liu Huan-Bin Li Hong-Zheng Chen Han-Ying Li MOE Key Laboratory of Macromolecular Synthesis and Functionalization State Key Laboratory of Silicon Materials Department of Polymer Science and Engineering Zhejiang University

Field-effect transistors（FETs） of three diketopyrrolopyrroles（DPP）-based small molecules, 3,6-bis（5-phenylthiophene-2-yl）-2,5-bis（2-ethylhexyl）pyrrolopyrrole-1,4-dione（PDPPP）, 3,6-bis（5-（4-fluorophenyl）thiophene-2-yl）-2,5-bis（2-ethylhexyl）pyrrolo pyrrole-1,4-dione（FPDPPPF） and 3,6-bis（5-（4-n-butylphenyl）thiophene-2-yl）-2,5-bis（2-ethylhexyl）pyrrolo pyrrole-1,4-dione（Bu PDPPPBu）, have been studied in this work. Well aligned crystals of the three molecules were grown from para-xylene by droplet-pinned crystallization method. FETs based on these aligned crystals exhibit a hole mobility up to0.19 cm^2 V 1s 1and electron mobility up to 0.008 cm^2 V 1s 1. The achieved hole mobility is of the same order of magnitude as reported highest hole mobility for DPP-based small molecules, but it is much lower than that of the high-performance DPP-based polymers. The relative low mobility is mainly attributed to the rough crystal surfaces with steps and, thus, non-smooth charge transport channels at the interfaces between the crystals and the dielectrics. This work has implications for understanding the low charge mobility of DPP-based small molecules.

关键词： Diketopyrrolopyrrole Crystals Solution processing Organic field-effect transistors Morphology

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Gel-incorporated PbS and PbI_2 single-crystals

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Chinese Chemical Letters 2015年第5期26卷 504-508页

作者： Wei Liu Yu-Jing Liu Liao Chen Tao Ye Hong-Zheng Chen Han-Ying Li MOE Key Laboratory of Macromolecular Synthesis and Functionalization State Key Laboratory of Silicon MaterialsDepartment of Polymer Science and EngineeringZhejiang University

Gel-incorporated single-crystals provide unique combinational properties of long-range order and composite structures, which is desired for semiconducting and conducting materials. However, the reported gel-incorporated single-crystals are limited to insulating crystals. Here, we examine crystals of two typical semiconductors, lead sulfide （PbS） and lead iodide （Pbl2）, grown from both silica gels and agarose gels. In all the four crystal-gel pairs, single-crystals of the cubic phase of PbS and the hexagonal phase of Phi2 were obtained according to the X-ray diffraction analysis. Dissolution of the gel-grown crystals exposed insoluble materials with the shape similar to the original crystals, indicative of gelincorporation inside the crystals. As such, this work creates a facile strategy to construct 3D heterostructures inside serniconducting single-crystals without destroying their long-range order.

关键词： Single crystals Gel-incorporation Semiconductor PbS Phi2

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Electron-deficient core fused-ring based non-fullerene acceptor enables over 15% efficiency in single junction organic solar cells

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Science China Chemistry 2019年第4期62卷 403-404页

作者： Hongzheng Chen State Key Laboratory of Silicon Materials MOE Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and Engineering Zhejiang University

Organic solar cells(OSCs)are promising to access flexible,light weight and semi-transparent photovoltaic devices by low-cost solution ***,the fused-ring nonfullerene acceptors play an important role in promoting the research progress of the *** power conversion efficiencies(PCEs)have been rapidly boosted to over 14%in single junction OSCs with the development of new nonfullerene acceptors and the related devices[1-3].Although the PCEs of OSCs are still inferior to their inorganic counterparts,further improvement of the PCEs could be expected by the development of new photovoltaic materials.

关键词： Electron-deficient core single junction non-fullerene acceptor

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Polypropylene Separators with Robust Mussel-inspired Coatings for High Lithium-ion Battery Performances

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Chinese Journal of Polymer Science 2019年第10期37卷 1015-1022,I0005页

作者： Chao Zhang Hong-Qing Liang Jun-Ke Pi Guang-Peng Wu Zhi-Kang Xu Key Laboratory of Macromolecular Synthesis and Functionalization (Ministry of Education) and Key Laboratory of Adsorption and Separation Materials and Technologies of Zhejiang Province Department of Polymer Science and Engineering Zhejiang University

The performances of lithium-ion batteries(LIBs)are dependent on the wettability and stability of porous *** coatings seem to be useful to improve the surface wettability of commercialized polyolefin ***,it is still a challenge to guarantee their stability under polar ***,we report a facile and versatile way to enhance the wettability and stability of polypropylene separators by constructing robust polydopamine(PDA)coatings triggered with CuSO4/*** coatings were conveniently deposited on the polypropylene separator surfaces and the PDA-coated separators exhibited the improved surface wettability and thermal *** electrolyte uptake increased nearly two folds from the pristine separator to the modified ***,the ionic conductivity also rose from 0.82 mS·cm^-1 to 1.30 mS·cm^-*** importantly,the CuSO4/H2O2-triggered PDA coatings were very stable under strong polar electrolytes,endowing the cells with excellent cycle performance and enhanced C-rate ***,the results unequivocally demonstrate that application of PDA coatings on polyolefin separator triggered by CuSO4/H2O2 is a facile and efficient method for improving the wettability and stability of separators for high LIBs performance.

关键词： Polypropylene separator Lithium-ion battery Surface wettability Dopamine Mussel-inspired coatings

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Surface-grafted block copolymer brushes with continuous composition gradients of poly(poly(ethylene glycol)-monomethacrylate) and poly(N-isopropylacrylamide)

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Science China Chemistry 2011年第2期54卷 334-342页

作者： LI LinHui WU JinDan GAO ChangYou MOE Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and EngineeringZhejiang UniversityHangzhou 310027China

Surface-grafted block copolymer brushes with continuous composition gradients containing poly(poly(ethylene glycol) monomethacrylate) (P(PEGMA)) and poly(N-isopropylacrylamide) (PNIPAAm) chains were fabricated by integration of the surface-initiated atom transfer radical polymerization (SI-ATRP) and continuous injection method. Three types of copolymer gradients were prepared: (1) a uniform P(PEGMA) layer was block copolymerized with a gradient PNIPAAm layer (PP1); (2) a gradient P(PEGMA) layer was block copolymerized with a uniform PNIPAAm layer (PP2); and (3) a gradient P(PEGMA) layer was inversely block copolymerized with a gradient PNIPAAm layer (PP3). The as-prepared gradients were characterized by ellipsometry, water contact angle and atomic force microscopy (AFM) to determine their alterations in thickness, surface wettability and morphology, confirming the gradient structures. In vitro culture of HepG2 cells was implemented on the gradient surfaces, revealing that the cells could adhere at 37 ℃ and be detached at 20 ℃. Introduction of the PEG chains as an underlying layer on the PNIPAAm grafting surfaces resulted in faster cell detachment compared with the PNIPAAm grafting surface.

关键词： gradients ATRP PNIPAAm cell attachment thermo-responsive

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In-depth study on aminolysis of poly(ε-caprolactone): Back to the fundamentals

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Science China Chemistry 2012年第11期55卷 2419-2427页

作者： ZHU Yang MAO ZhengWei SHI HuaYu GAO ChangYou MOE Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and EngineeringZhejiang UniversityHangzhou 310027China

The aminolysis can effectively introduce primary amine （- quent surface fiiofunctionalization reactions. However, less NH2） groups onto polyester materials, enabling a variety of subse- attention has been paid to the basic knowledge of aminolysis reac- tion in terms of reaction kinetics and its influences on materials properties. In this study, taking the widely used poly（e-caprolactone）（PCL） as a typical example, the influences of diamines and solvent property on the surface -NH2 density are firstly assessed by using X-ray photoelectron spectroscopy （XPS） and colorimetric analysis. Results show that smaller dia- mine molecules and nonpolar alcohols could accelerate the reaction. The reaction kinetics with 1,6-hexanediamine is further investigated as a function of temperature, reaction time, and diamine concentration. During the initial stage, the reaction shows a 1^st order kinetics with the diamine concentration and has an activation energy of 54.5 kJ/mol. Ionization state of the -NH2 groups on the PCL surface is determined, revealing that the pKa of -NH3^＋（〈5） is much lower than that of the corresponding diamine molecules in solution. After aminolysis, surface hydrophilicity of PCL membrane is significantly enhanced, while surface elastic modulus and average molecular weight are decreased to some extent, and others such as weight, surface mor- phology and bulk mechanical strength are not apparently changed. The introduced -NH2 groups are found to be largely lost at 37 ℃, but can be mostly maintained at low temperature.

关键词： poly（ε-caprolactone） aminolysis surface modification biomaterials

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Room temperature polymerization of alkyl isocyanates catalyzed by rare earth Schiff base complexes

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Science China Chemistry 2009年第11期52卷 1843-1850页

作者： XiongFa Yang XuFeng Ni ZhiQuan Shen Key Laboratory of Macromolecular Synthesis and Functionalization Ministry of Education Institute of Polymer Science Zhejiang University Hangzhou 310027 China

The polymerization of alkyl isocyanates catalyzed by rare earth chloride salen complexes/triisobutyl aluminum (Ln(H2salen)2Cl3·2C2H7OH/Al(i-Bu)3) at room temperature was investigated. The influences of ligand str... 详细信息

The polymerization of alkyl isocyanates catalyzed by rare earth chloride salen complexes/triisobutyl aluminum (Ln(H₂salen)₂Cl₃·2C₂H₇OH/Al(i-Bu)₃) at room temperature was investigated. The influences of ligand structure, catalyst composition, polymerization temperature, polymerization time, the concentration of catalyst and monomer, and the polymerization solvent on the polymerization of isocyanates were studied. It was found that under the polymerization conditions, examined La(H₂salen_A)₂Cl₃·2C₂-H₇OH/Al(i-Bu)₃ (H₂salen_A= N,N′-disalicylideneethylene diamine) is a fairly high efficient catalyst for the polymerization of n-hexyl isocyanate (n-HexNCO) to prepare high molecular weight poly(n-hexyl isocyanate) (PHNCO) with narrower molecular weight distribution at room temperature. PHNCO could be prepared with yield of 74.0%, number-average molecular weight (M _n) of 40.20×10⁴ and MWD of 1.79 under the following optimum conditions: [Al]/[La] = 30 (molar ratio), [n-HexNCO]/[La] = 100 (molar ratio), [n-HexNCO] = 3.43 mol/L polymerization at 20°C for 12 h in toluene. In the same polymerization conditions, poly (n-octyl isocyanate) (PONCO) with yield of 67.3%, and poly(n-butyl isocyanate) (PBNCO) with yield of 45.5%, could be prepared respectively. The kinetics of the polymerization of n-HexNCO was also investigated and found to be first-order with respect to both monomer and catalyst concentrations.

关键词： rare earth catalyst Schiff base complex polymerization alkyl isocyanate

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Surface glycosylation of polymeric membranes

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Science China Chemistry 2008年第10期51卷 901-910页

作者： DAI ZhengWei WAN LingShu XU ZhiKang Key Laboratory of Macromolecular Synthesis and Functionalization of Ministry of Education Institute of Polymer ScienceZhejiang UniversityHangzhou 310027China

Surface glycosylation of polymeric membranes has been inspired by the structure of natural biomem-branes. It refers to that glycosyl groups are introduced onto the membrane surface by various strate-gies, which combine the separation function of the membrane with the biological function of the sac-charides in one system. In this review, progress in the surface glycosylation of polymeric membranes is highlighted in two aspects, i.e. the glycosylation methods and the potential applications of the sur-face-glycosylated membranes.

关键词： membrane surface glycosylation enzyme immobilization protein recognition

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Assessing the synergy effect of additive and matrix on single-crystal growth: Morphological revolution resulted from gel-mediated enhancement on CIT-calcite interaction

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Chinese Chemical Letters 2018年第8期29卷 1296-1300页

作者： Yujing Liu Ying Tan Jie Ren Hongzheng Chen Hanying Li MOE Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and Engineering State Key Laboratory of Silicon Materials Zhejiang University

It is well known that in biomineralization, the inorganic solids crystallized in the presence of organic phases, which are generally recognized as additives and matrix, leading to the crystal morphology modification. However, the synergy effects of both soluble additive and insoluble matrix on regulating the morphology of synthetic single-crystals are less studied. Here, we examine the morphological revolution of calcite single crystals induced by the additive, citrate（CIT）, or/and the matrix, agarose gel network. The agarose gel matrix is inert to the crystal morphology in the sense that the agarose gelgrown calcite crystals maintain in characteristic rhombohedra. In contrast, CIT additives are active in crystal morphology modification and crystals begin to exhibit curved rough surfaces when grown in solution with the concentration of CIT coated Au nanoparticles（[CIT-Au NPs]） of more than 2.25 mg/***, once agarose gel and CIT-Au NPs are simultaneously introduced, the curved morphological feature emerges at a much lower [CIT-Au NPs] of around 0.2 mg/mL. Increasing the gel concentrations further reduce the [CIT-Au NPs] needed to trigger calcite morphological modification, suggesting that the gel networks reduce the CIT diffusion and thereby enhance the kinetic effects of CIT on crystallization. As such, this work may have implications for understanding the mechanism of hierarchical biominerals construction and provide rational strategy to control single-crystal morphologies.

关键词： Biomineralization Synergy effect Additive CIT Gel matrix Calcite single-crystal Morphology

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Self-assembly and pH-Responsive Properties of Poly(L-glutamic acid-r-Lleucine) and Poly(L-glutamic acid-r-L-leucine)-b-Polysarcosine

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Chinese Journal of Polymer Science 2015年第8期33卷 1186-1195页

作者： Ce Tian 凌君 You-qing Shen MOE Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and EngineeringZhejiang University Department of Chemical and Biological Engineering Zhejiang University

Polypeptides and polypeptoids were widely used as biomedical materials because of their good biocompatibility. In this work we reported a series of pH-responsive copolypeptides and polypeptide-polypeptoid block copolymers, i.e. random copolymers of L-glutamic acid （Glu） with L-leucine （Leu） [poly（Glu-r-Leu）s], as well as their block copolymers with polysarcosine （polySar）. Well-defined poly（Glu-r-Leu）s with predictable compositions and molecular weights were synthesized by ring opening polymerization of corresponding N-carboxyanhydride monomers. We investigated the relationship between hydrophilicity-hydrophobicity transition and copolymer composition. With increasing Leu fraction, both the pH value of cloud point and the micellar size increased. Poly（Glu-r-Leu） with 60% Leu exhibited a cloud point at the pH of 5.0 to 6.0 the same as that in endosome and lysosome. Poly（Glu-r-Leu）-b-polySars assembled in phosphate buffer and performed pH-responsive morphology change from orbicular micelles at high pH to worm-like micelles at low pH. They were potential pH-responsive carriers for drug and gene delivery to enhance cargo release in cellules.

关键词： α-Amino acid NCA Random/block copolypeptide pH-Responsive Hydrophilicity-hydrophobicity transition.

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