POLYMERS FOR ADVANCED TECHNOLOGIES
·
2014
·Vol. 25
·期 9
·920-926
·
IF 1.964
Cuihong Zhang,Dongrui Wang,Jin He,Tao Liang,Guo-Hua Hu,Zhi-Min Dang
In this work, self-assembly method was used to improve the dielectric constant of triblock copolymers. A series of ABA triblock copolymers with a defined length of poly(n-butyl acrylate) (PBA, B block) segment and different lengths of liquid crystalline (LC) poly[11-(4-cyano-4′-biphenoxy)undecyl methacrylate] (P11CBMA, A block) segments were synthesized by using the atom transfer radical polymerization method. The well-defined triblock copolymers P11CBMA m - b -PBA n - b -P11CBMA m possess three different B/A ratios ( n = 50, m = 17, 43, 53). Due to the supramolecular cooperative motion effect, the copolymers can form worm-like microstructure ( W LC = 52.8%), cylinder-like nanostructure with P11CBMA phase embedded in PBA matrix ( W LC = 73.9%), and wide stripe structure with LC domains distributed unevenly in a continuous PBA matrix ( W LC = 77.7%) after annealed at 160°C (above T i ) under N 2 for 24 h, respectively. In order to study the influence of microphase separated morphology of triblock copolymer on the dielectric properties, solvent annealing was also used to develop various nanostructures. After thermal or solvent annealing, the dielectric constants of block copolymers increased dramatically while their loss factors remained the same. For different block copolymers, the dielectric constants increased with the increase of the LC block length. For diverse treatments, dielectric permittivities of samples varied widely with different nanostructures. The results show that the dielectric constants of block copolymers could be tuned by the block ratios and the self-assembled microstructures. These findings will inspire researchers using self-assembly method to design and develop novel flexible materials with high dielectric permittivity. Copyright © 2014 John Wiley & Sons, Ltd.
研究领域:
材料科学
·
高分子化学
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DOI
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 31
·24231-24238
·
IF 3.84
Tongming Sun,Jinli Zhu,Miao Wang,Minlei Lu,Jinjin Ding,Ziting Lv,Ping Hua,Yuejun Zhang
A new glucosyl triblock copolymer, poly(acryloyl glucofuranose)-block-poly(N-isopropyl acrylamide)-block-poly(acrylic acid) (PAG-b-PNIPAM-b-PAA, i.e., PGNA), was first synthesized from 3-O-acryloyl-1,2;5,6-di-O-isopropylidene-α-D-(−)-glucofuranose (ADIPG), tert-butyl acrylate (tBA) and N-isopropyl acrylamide (NIPAM) in the presence of the initiator 2,2-azoisobutyronitrile (AIBN) by sequential reversible addition–fragmentation chain transfer (RAFT) polymerization. In this RAFT process, 2,2′-thiocarbonylbis(sulfanediyl)bis(2-methylpropanoic acid) (CMP) was synthesized and used as a chain transfer agent. PGNA and the reaction intermediates were characterized by FT-IR, HNMR and GPC. When heated, the aqueous PGNA copolymer solution exhibits good sol–gel phase transition behaviours. Meanwhile, the formed hydrogels are also sensitive to the pH. When the copolymer solution is injected into a living Sprague Dawley (SD) rat, an in situ gel is formed within 3 minutes. By using acetylsalicylic acid (aspirin) as a model, drug release tests show that the maximum releasing value is approximately 76% under physiological conditions (pH 7.4, 37 °C). The synthesized triblock copolymer shows no apparent cytotoxicity towards L929 fibroblast cells according to an in vitro cytotoxicity test (MTT assay).
研究领域:
高分子化学
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生物材料
·
药剂学
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DOI
高影响因子
ELECTROCHIMICA ACTA
·
2016
·
IF 4.803
Ying Liu,Lingyang Liu,Lingbin Kong,Long Kang,Fen Ran
Metal nitride-based supercapacitors can provide superb electrical conductivity, high capacitance, and wide operating potential window, but they do not have sufficient fabrication strategy to construct advanced nano-structure beneficial to electrochemical process. In this paper, we report an in-situ preparation approach of vanadium nitride nanoparticles on porous carbon nanospheres (PCNS@VNNP) by the ammonification process of ionic amphiphilic triblock copolymer micelles/vanadium-contained ions system in NH 3 /N 2 atmosphere. The prepared PCNS@VNNP material has a wide operating potential of 1.2 V, and a capacitance of 229.7 F/g (275.6C/g). A hybrid supercapacitor device of PCNS@VNNP//NiO exhibits a high energy density of 16 Wh/kg at the power density of 800 W/kg. The improvement mostly stems from the quantum dot size of vanadium nitride and the supporting of porous carbon, which would dramatically enhance the utilization of active material without affecting its electric conductivity.
研究领域:
材料科学
·
电化学
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DOI
高影响因子
COLLOIDS AND SURFACES B-BIOINTERFACES
·
2021
·
IF 5.268
Yufeng Zhang,Yanliang Dong,Junhui Zhou,Wenjun Huang,Yidi Wu,Shuyue Zhao,Yongli Shi,Suping Bai,Chunhui Li,Yuanyu Huang,Anjie Dong
Optimal combination of hydrophobic-hydrophilic balance, proton buffering and electrostatic interaction is the key issue for designing polycations as efficient gene vectors and antibacterial agents . Herein, we screened a series of pH-sensitive quaternary ammonium-based amphiphilic triblock copolymers , mPEG 2k -P(DPA a /DMA b )-PQA c (TDDE-x), which had different pKa values and proton buffering capacities. Significantly, we found that both the highest siRNA intracellular delivery efficiency and the strongest antibacterial capacity occurred on TDDE-3 micelles with the segment structure of mPEG 2k -P(DPA 50 /DMA 56 )-PQA 55 . The TDDE-3/siRNA complex achieved 67% silencing efficiency on H9C2 cells (N/P = 5, 50 nM siRNA), higher than the advanced commercial transfection reagents RNAiMAX (58%) and Lipo2000 (30%). Moreover, TDDE-3 micelles showed quite low MICs of 32 μg/mL and 8 μg/mL against E. coli and S. aureus , respectively. Further studies on the structure-function relationship indicated that TDDE-3 micelles could mediate robust endosome escape and siRNA cytosolic release, and strong bacterial cell membrane-destabilizing function. Undoubtedly, this work reveals the possibility for double optimization of siRNA intracellular delivery efficiency and antibacterial activity of amphiphilic polycations by reasonable structure design, which is significant for low-cost development and clinical translation of efficient multifunctional polycations.
研究领域:
生物材料学
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基因治疗
·
抗菌研究
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产品关联
DOI
PubMed
高影响因子
CHINESE CHEMICAL LETTERS
·
2022
·
IF 8.455
Kun An,Jia Gao,Yihang Chen,Jingjing Nie,Yongjin Li,Junting Xu,Binyang Du
A series of linear poly(ethylene oxide)- b -poly(4-vinylbenzyl chloride)- b -poly(4‑ ter t-butylstyrene) (PEO 113 - b -PVBC 130 - b -P t BS x or E 113 V 130 T x ) triblock terpolymers with various lengths x (=20, 33, 66, 104, 215) of P t BS block were synthesized via a two-step reversible addition-fragmentation chain transfer (RAFT) polymerization. The E 113 V 130 T x triblock terpolymers were non-crystalline because the PVBC and P t BS blocks strongly hindered the crystallization of PEO block. The effects of P t BS block length x on the phase structures of E 113 V 130 T x triblock terpolymers were investigated by combined techniques of small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM). It was found that with increasing x from 20 to 215, the phase structure of E 113 V 130 T x triblock terpolymers became more ordered and changed from disordered structure , hexagonally-packed cylinder (HEX), hexagonally perforated layer (HPL), to lamellar (LAM) phase structures. Temperature-variable SAXS measurements showed that the HEX, HPL and LAM phase structures obtained for E 113 V 130 T 66 , E 113 V 130 T 104 and E 113 V 130 T 215 by thermal annealing, respectively, were thermodynamically stable in the temperature range of 30–170 °C.
研究领域:
材料科学
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高分子化学
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DOI
高影响因子
POLYMER
·
2022
·
IF 4.432
Jing Yan,Jianghao Yao,Yinghui Hu,Diping Huang,Dongdong Yao,Fangzhou Wu,Qiuyu Zhang,Yi Yan
To enrich the building block and function as well as the preparation methodology of metallopolymer system, functioned inorganic polyoxometalate clusters were introduced by using their intrinsic acidity induced multiple interactions with triblock copolymers . In the designed triblock copolymer PEG- b -PDMAEMA- b -PTEPM, the POMs clusters can be immobilized through in-situ protonation of the PDMAEMA block induced electrostatic interaction and the self-gelation of the PTEPM block, while the PEG block can improve the water solubility and dispersion of the final polyoxometalate-based hybrid catalyst (PHC). The selective oxidation activity of PHC is comparable with the homogeneous POMs catalyst as demonstrated by the model reaction of the selective oxidation of methyl phenyl sulfide (MPS) to methyl phenyl sulfoxide (MPSO). By optimizing the ratio between PHC and oxidant H 2 O 2 , the selectivity for MPSO can achieve as high as 99% with conversion above 95%. Furthermore, the multiple interactions between POMs and the polymer substrate also enhance the stability of PHC and enable the recycling of PHC. Therefore, the methodology of in-situ protonation and self-gelation by the acidity of POMs provides a facile and general strategy to prepare robust POMs-based metallopolymers, paving a new avenue towards cluster-based materials and devices.
研究领域:
材料科学
·
催化化学
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产品关联
DOI
高影响因子
EUROPEAN POLYMER JOURNAL
·
2024
·
IF 5.8
Kun Liu,Yawen Fu,Qiqi Dai,Haoyun Tan,Zhuowei Gu,Qiaoqiao Xiong,Shuai Yang,Mingming Zhang,Jianxiang Feng,Wenjun Yi,Lijun Li
Pure multi-block copolymers and deformed multi-block copolymers have unique applications in the field of high-performance thermoplastic elastomers, resins and rubber materials. For styrene ( S ) and conjugated 1,3-dienes ( e.g. 1,3-pentadiene, P ) monomers, living anionic polymerization ( LAP ) has significant advantages in precise control of molecular weight and its distribution and precise control of microstructure and the sequence distribution. Subsequently, the post-polymerization modification strategy including epoxidation can further expand the application field of such polymer materials. Herein, a series of novel symmetrical triblock copolymers of different compositions with homo-polystyrene as end-blocks and strictly alternating sequence as mid-block, poly( S )- b -poly( S - alt - P )- b -poly( S ) ( SSPS ), were synthesized in cyclohexane by the classical three-step sequential feeding method using n -BuLi as initiator. The effect of the block ratio of SSPS triblock copolymer on impact strength, flexural strength and yield strength of transparent resin products was studied in detail. In addition, quantitative epoxidation post-polymerization functional modification was performed to obtain the novel triblock copolymer product which had a high-polarity and high-transparent thermoplastic resin with well-defined structure and quantitative degree of epoxidation ( ED ). All these novel copolymers before and after modification were characterized by 1 H NMR, 13 C NMR, FTIR, DSC and GPC.
研究领域:
材料科学
·
高分子化学
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产品关联
DOI
高影响因子
REACTIVE & FUNCTIONAL POLYMERS
·
2019
·
IF 3.074
Junqiang Zhao,Hongrui Han,Qiqi Wang,Chengyou Yan,Dongyang Li,Jing Yang,Xia Feng,Ning Yang,Yiping Zhao,Li Chen
To fabricate hydrophilic and anti-fouling PVDF ultrafiltration membrane, a kind of tailor-made symmetrical amphiphilic triblock copolymer , polyacryloylmorpholine- b -poly (methyl methacrylate)- b -polyacryloylmorpholine (PACMO- b -PMMA- b -PACMO, termed as PAMA), was prepared via RAFT polymerization and employed as an in situ surface segregation modifier. FTIR, 1 H NMR, and GPC were used to verify the well-defined chemical structure of PAMA. The hydrophilic PACMO segments of PAMA were enriched on the surface of membrane skin and interior pores as confirmed by ATR-FTIR, XPS , EDX, and water contact angle tests, endowing the blend membranes with outstanding hydrophilicity . The different cross-sectional and surface morphologies of the PVDF/PAMA blend membranes indicated that the introduction of PAMA modifiers could manipulate membrane structure due to their strong pore-forming ability. Compared with the pure PVDF membrane, PVDF/PAMA blend membranes showed higher permeability for water (28.1 times higher), excellent rejection for bovine serum albumin (up to 98.3%), and enhanced fouling resistance with a higher flux recovery ratio (up to 98.1%). Therefore, the approach of in situ surface segregation employed the RAFT mediated well-defined amphiphilic PAMA triblock copolymer modifiers for the preparation of anti-fouling PVDF membranes showed a great potential in water purification .
研究领域:
材料科学
·
环境工程
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DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2019
·
IF 6.361
Haotian Shi,Teng Qiu,H. Daniel Ou-Yang,Huangbing Xu,Qingchuan Lu,Ying Zheng,Kexin Liu,Lifan He,Longhai Guo,Xiaoyu Li
A temperature sensitive sol-gel transition induced by the self-assembly of amphiphilic copolymers and its application in industry have been the objects of increasing study. We demonstrate here a two-step, reversible addition-fragmentation chain transfer (RAFT) polymerization of an ABA-type copolymer consisting of poly( N,N -dimethylacrylamide)- b -poly(diacetone acrylamide)- b -poly( N,N -dimethylacrylamide) (PDMAA- b -PDAAM- b -PDMAA). This copolymer can be easily dispersed in water, and this dispersion is critical for its lower critical solution temperature (LCST)-type sol-gel transition, which was monitored using dynamic light scattering (DLS), transmission electron microscopy (TEM), and rheology analysis, in addition to temperature-dependent 1 H nuclear magnetic resonance ( 1 H NMR) and Fourier transform infrared spectroscopy (FTIR). Results revealed an abnormal sphere-to-worm micellar transition of this ABA copolymer at the LCST point, which could be affected by the length of the PDAAM block (B-block), the length as well as the distribution of the PDMAA block (A-block), and the concentration of the copolymer dispersion. Thus, copolymer dispersion could be feasibly used for drug loading at a low temperature, which could then be transformed into a gel at an elevated temperature. The loading and controllable release of the model drug of paracetamol into and out of a copolymer gel was further determined. The sustained release behavior was also studied using the Rigter-Peppas model.
研究领域:
材料科学
·
生物医学工程
·
高分子化学
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DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2020
·Vol. 138
·期 12
·50085
·
IF 2.52
Lu Dai,Suyun Jie,Zhiyang Bu,Bo-Geng Li
Two series of triblock copolymers, polycaprolactone- b -polybutadiene- b -polycaprolactone (PCL- b -PB- b -PCL, CBC) and polylactide- b -polybutadiene- b -polylactide (PLA- b -PB- b -PLA, LBL), have been synthesized through the ring-opening polymerization (ROP) of ε-caprolactone (ε-CL)/ D,L -lactide ( D,L -LA) catalyzed by Sn(Oct) 2 with hydroxyl-terminated polybutadiene (HTPB) as a macroinitiator. Then, these triblock copolymers are end-functionalized with 2-ureido-4[1H]-pyrimidinone (UPy) groups to obtain the supramolecular multiblock copolymers UCBC and ULBL as supramolecular thermoplastic elastomers (TPEs). The thermal properties of UCBC and ULBL samples are measured by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA). The tensile tests of all the samples prepared are carried out to investigate the influence of the content of hard segments and the microstructure of PB soft segments on the mechanical properties of supramolecular TPEs.
研究领域:
材料科学
·
高分子化学
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DOI
高影响因子
POLYMER SCIENCE SERIES B
·
2019
·Vol. 61
·期 5
·550-559
·
IF 0.907
Xin-Ru Dai,Geng Yue,Shao Guangqiang,Luo Zhang,Jiang Xiubo,Zhang Zhen-Xiu
Abstract Here triblock copolymer synthesis mediated by trans -1,4-polyisoprene is reported for the first time. Carbonyl telechelic trans -1,4-polyisoprene ( trans -structure >95%) was synthesized by the epoxidation of trans -1,4-polyisoprene followed by oxidative cleavage. Bromine terminated trans -1,4-polyisoprene was then synthesized by the reduction reaction of carbonyl groups of trans -1,4-polyisoprene to hydroxyl groups followed by end group transformation. Atom transfer radical polymerization of styrene was conducted then using bromine terminated trans -1,4-polyisoprene as macroinitiator. Triblock copolymers were characterized by 1 H-NMR, FTIR, GPC, DSC, and XRD.
研究领域:
材料科学
·
高分子化学
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产品关联
DOI
高影响因子
MINERALS ENGINEERING
·
2019
·
IF 3.315
Yupeng Qian,Xukun Qin,Yongjun Peng
Slime coating is a common problem in mineral flotation and this study explored a novel idea to mitigate slime coating to improve mineral flotation. Guided by the previous work, Pluronic triblock copolymer F-127 (PEO 100 PPO 65 PEO 100 ) was chosen to mitigate fine quartz coating in fluorite flotation. Then the mechanism underpinning the mitigation of fine quartz coating on fluorite surface by F-127 and the interaction of F-127 with collector sodium oleate on quartz and fluorite surfaces were studied. It was found that F-127 adsorbed on both quartz and fluorite surfaces and therefore mitigated fine quartz coating on fluorite surface through steric repulsion. The adsorbed F-127 on fluorite surface also enhanced the adsorption of sodium oleate but had little effect on the adsorption of sodium oleate on quartz surface. The mitigation of fine quartz coating and enhanced adsorption of sodium oleate on fluorite surface explain the significantly improved fluorite flotation in the presence of fine quartz particles after the addition of F-127.
研究领域:
矿物加工工程
·
材料科学与工程
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）