POLYMER BULLETIN
·
2017
·Vol. 75
·期 7
·2917-2931
·
IF 1.43
Ding Amin,Teng Lijing,Zhou Yifeng,Chen Pengpeng,Nie Wangyan
The star-shaped poly( l -lactide) (s-PLLA) was synthesized via ring-opening polymerization of l -lactide, with xylitol as a multifunctional initiator and stannous octoate as a catalyst. The structures of s-PLLA were characterized by 1 H NMR spectroscopy, while the molecular weight ( M
w ) and polydispersity index were determined by gel permeation chromatography. Bovine serum albumin (BSA) loaded s-PLLA microspheres were fabricated by a water–oil–water ( W
1 / O / W
2 ) double-emulsion solvent evaporation method. The morphology, drug encapsulation efficiency (EE), and in vitro release behavior of the prepared microspheres were studied in detail. Results indicated that the average diameters of s-PLLA microspheres could be controlled between 7 and 15 µm by varying the s-PLLA’s concentration or M
w , and the drug encapsulation efficiency of BSA-loaded microspheres were 10–42%. The in vitro study shows that the BSA-loaded microspheres prepared by high molecular weight s-PLLA had a slow cumulative release behavior in phosphate buffer saline (PBS, pH 7.4) and the release process followed the Baker–Lonsdale equation. Present work supposes that the synthesized s-PLLA is a good candidate for drug delivery.
研究领域:
生物材料学
·
药剂学
✓ 已验证
DOI
高影响因子
Science China-Chemistry
·
2015
·Vol. 58
·期 2
·357-363
·
IF 1.695
Zhou Yuanhang,Chen Weichao,Du Zhengkun,Zhu Dangqiang,Ouyang Dan,Han Liangliang,Yang Renqiang
A new star-shaped small molecule named TCNR3TTPA, with a triphenylamine (TPA) unit as the central building block and 2-(1,1-dicyanomethylene)-3-octyl rhodanine (CNR) as the end-capped group, has been designed and synthesized. TCNR3TTPA showed a deep highest occupied molecular orbital (HOMO) energy level (−5.60 eV) and broad absorption. The solution-processed bulk heterojunction (BHJ) solar cells based on TCNR3TTPA:PC 61 BM (1:1, w / w ) exhibited a high open-circuit voltage ( V
oc ) of 0.99 V, a short-circuit current density ( J
sc ) of 5.76 mA/cm 2 , and a power conversion efficiency (PCE) of 2.50% under the illumination of AM 1.5 G, 100 mW/cm 2 . The high V
oc is ascribed to the strong electron-with- drawing ability of the end-capped 2-(1,1-dicyanomethylene)-3-octyl rhodanine group. These results demonstrated that the V
oc of small-molecule organic solar cells could be increased by introducing a strong electron-withdrawing end-capped block, and that this is an effective strategy to design high-performance small molecules for organic solar cells.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
高影响因子
JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY
·
2010
·Vol. 48
·期 24
·5643-5651
·
IF 3.971
Peng-Fei Gou,Wei-Pu Zhu,Zhi-Quan Shen
Novel calixarene-centered amphiphilic A 2 B 2 miktoarm star copolymers composed of two PCL arms and two PEG arms with calix[4]arene as core moiety were synthesized by the combination of CROP and “click” chemistry. First, a heterotetrafunctional calix[4]arene derivative with two hydroxyl groups and two alkyne groups was designed as a macroinitiator to prepare calixarene-centered PCL homopolymers (C4-PCL) by CROP in the presence of Sn(Oct) 2 as catalyst at 110 °C. Next, azide-terminated PEG (A-PEG) was synthesized by tandem treating methoxy poly(ethylene glycol)s (mPEG) with 4-chlorobutyryl chloride and NaN 3 . Finally, copper(I)-catalyzed cycloaddition reaction between C4-PCL and A-PEG led to A 2 B 2 miktoarm star copolymer [C4S(PCL) 2 -(PEG) 2 ]. 1 H NMR, FT-IR, and SEC analyses confirmed the well-defined miktoarm star architecture. These amphiphilic miktoarm star copolymers could self-assemble into multimorphological aggregates in water. The calix[4]arene moieties with a cavity <1 nm on the hydrophilic/hydrophobic interface of these aggregates may provide potential opportunities to entrap guest molecules for special applications in supermolecular science. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
研究领域:
高分子化学
·
超分子科学
✓ 已验证
DOI
高影响因子
MICROCHIMICA ACTA
·
2018
·Vol. 186
·期 1
·1-7
·
IF 5.705
Song Wen-Fang,Zhao Qing-Li,Zhou Xiu-Jie,Zhang Li-Shun,Huang Yan-Ping,Liu Zhao-Sheng
A star-shaped molecularly imprinted coating was prepared starting from octavinyl-modified polyhedral oligomeric silsesquioxanes (Ov-POSS). It possesses a relatively open structure and has good site accessibility and a larger capacity even at lower cross-linking. The imprinted coating was prepared from S -amlodipine ( S -AML) as the template and analyte, Ov-POSS as the cross-linker, and methacrylic acid as the functional monomer. The preparation and chromatographic parameters were optimized, including ratio of template to functional monomer, apparent cross-linking degree, pH value, ACN content and salt concentration in the mobile phase. The best resolution in enantiomer separation by means of capillary electrochromatography reaches a value of 33. A good recognition ability (α = 2.60) was obtained and the column efficiency for S -AML was 54,000 plates m −1 . The use of Ov-POSS as a cross-linker significantly improves the column capacity and thus the detection sensitivity. The results show that Ov-POSS is an effective cross-linker for the preparation of imprinted polymers with good accessibility and large capacity.
Schematic presentation of the preparation of star-shaped imprinted polymer using octavinyl-modified polyhedral oligomeric silsesquioxanes (Ov-POSS) and by using methacrylic acid (MAA) as functional monomer. The best enantiometric resolution (33) for amlodipine (AML) can be achieved in capillary chromatography (CEC).
研究领域:
分析化学
·
材料科学
·
药物化学
✓ 已验证
DOI
高影响因子
DYES AND PIGMENTS
·
2017
·
IF 3.473
Yafei Wang,Wanhui Liu,Zuoming Qu,Hua Tan,Yu Liu,Guohua Xie,Weiguo Zhu
To explore the structure-property of donor-acceptor (D-A) type blue emitter, in this contribution, four star-shaped compounds of p -TPA, m -TPA, p -TPA-TPE and m -TPA-TPE using spirotriphenylamine as the donor unit and triazine as the acceptor core were designed and prepared. The tetraphenylethene (TPE) unit was introduced into the D-A molecules to enhance the emission efficiency in solid state. The photophysical properties of all compounds were comparatively studied through experimental and theoretical methods. All these D-A compounds displayed blue emission (443–487 nm) both in solution and neat film. Compared to p -TPA and m -TPA, p -TPA-TPE and m -TPA-TPE possessed clear aggregated-induced emission (AIE) property and higher emission efficiency in the solid state. Both the doped and non-doped organic light-emitting diodes (OLEDs) based on m -TPA and m -TPA-TPE were fabricated by solution-processable approach. The m -TPA-TPE based non-doped device showed a satisfying performance with a high current efficiency of 4.2 cd/A and an external quantum efficiency of 1.8% in the bluish-green region. This research demonstrates that integrating AIE unit into D-A molecule is an effective strategy for design high efficient blue emitter in non-doped OLEDs.
研究领域:
材料科学
·
光学
·
化学
✓ 已验证
DOI
高影响因子
SOLID STATE IONICS
·
2022
·
IF 3.699
Jingyu Ma,Xiaoyan Ma,Qi Zhang,Xinghua Guan,Fang Chen,Peiran Wang,Junling Huang
Poly(ethylene oxide) (PEO)-based solid polymer electrolyte (SPE), as a key component connecting the internal channels, can improve the safety performance for lithium secondary battery , but it is still challenged by limited ionic conductance due to high polymer crystallinity at room temperature . Here, we develop a SPE by blending PEO with star -shaped polymer of polyethylene glycol methyl ether methacrylate- co -polyhedral oligomeric silsesquioxane (POSS-(PPEGMEM) 8 ), which is synthesized by atom transfer radical polymerization (ATRP) under octa (2-bromoisobutyryloxyethyl sulfide) octasilsesquioxane (POSS-Br 8 ) as initiator and poly(ethylene glycol) methyl ether methacrylate (PEGMEM) as polymerization monomer . The unique star -shaped structure of POSS-(PPEGMEM) 8 is helpful to increasing the segmental motion by reducing the crystallinity of PEO polymer and supporting more ion transport channels to obtain higher ion conductivity. The mixed electrolyte containing 40% POSS-(PPEGMEM) 8 exhibits the highest ionic conductivity (1.4 × 10 −4 S cm −1 , 50 °C) with a Li + transference number of 0.51 and a wide electrochemical window (5.0 V vs. Li/Li + ) and a high mechanical strength . The LiFePO 4 ||Li battery , assembled with PEO/POSS-(PPEGMEM) 8 –40%, carries out 100 cycles at a current density of 0.1C, provides a stable reversible capacity of 129.4 mAh g −1 and a high capacity retention rate due to the high ratio of free volume of polymer electrolyte formed by the star-shaped POSS-(PPEGMEM) 8 , which indicates that PEO/POSS-(PPEGMEM) 8 has good application prospects in high-performance all-solid-state lithium secondary battery.
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2019
·
IF 14.229
Ting Bian,Beibei Xiao,Biao Sun,Long Huang,Shan Su,Yi Jiang,Jiankun Xiao,Aihua Yuan,Hui Zhang,Deren Yang
The ultimate goal of catalyst design is to optimize catalytic performance by revealing the relationship between structure and activity. However, it remains tremendously challenging to distinguish the role of electronic and ensemble effects in bimetallic core-shell electrocatalysts for hydrogen evolution reaction (HER). For this purpose, we demonstrate an efficient approach to local epitaxial growth of Rh atoms on Au decahedra to investigate the above-mentioned two effects. Among them, Au 75 Rh 25 core-shell star-shaped decahedra exhibited the best activity for HER with an overpotential of 64.1 mV at a current density of 10 mA cm −2 , which is about 39.4 mV less than that of commercial Rh/C. Density function theory (DFT) calculations revealed that ensemble effect is the dominant factor to accelerate the reaction kinetics of HER by exposing Au atoms on the surface and thus weakening the strong adsorption of the intermediates on Rh surface.
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2018
·
IF 5.116
Zhangxin Chen,Weijun Li,Yuyu Dai,Ning Xu,Chang Su,Junlei Liu,Cheng Zhang
Based on the star-shaped structure, triphenylamine derivative 1,3,5-tris(4-diphenylamino-phenyl)benzene (TTPAB) with multiple active polymerization sites of three peripheral triphenylamine units was designed and synthesized, which was further prepared into the corresponding conjugated microporous polymer PTTPAB by chemical oxidative polymerization. The polymer PTTPAB powder exhibited the blossom sphere-like morphology with high surface area (595 m 2 /g) and plentiful micropores of the average diameter of 0.68 nm as well as mesopores of the small diameter of ∼ 2–5 nm. Being explored as the organic cathode material of battery , PTTPAB exhibited more remarkable rate performance of 84, 82, 81, 80, 84 mAh g −1 than that of PTPAn (81, 73, 72, 69, 82 mAh g −1 ) in the range of 2.5–4.2 V at current rate from 50 to 500 mA g −1 . This enhanced rate performances of PTTPAB was mainly attributed to the high specific surface area caused by the plentiful micropores and mesopores from the conjugated microporous polymer structure and blossom microspheres morphology. The high surface area can benefit to the reversible redox reaction available for Li + and shorten Li + diffusion pathway, that led to the more reduced charge transfer resistance (∼160 Ω for PTTPAB and ∼920 Ω for PTPAn), thereby improving the rate performance. Meanwhile, PTTPAB showed more stable cycling life with hardly any loss and higher coulomb efficiency during the 50th charge/discharge cycle. These excellent cell performances and unique micro-mesopores structure make PTTPAB polymer a good potential candidate as the organic cathode materials for high rate performance organic reachargeable batteries.
✓ 已验证
产品关联
DOI
高影响因子
MACROMOLECULAR CHEMISTRY AND PHYSICS
·
2017
·Vol. 218
·期 16
·1700178
·
IF 2.5
Xuefei Leng,Yingying Ren,Zhiyong Wei,Yufei Bian,Yang Li
A series of highly branched star-comb poly(ε-caprolactone)- block -poly( l -lactide) (scPCL- b -PLLA) are successfully achieved using star-shaped hydroxylated polybutadiene as the macroinitiator by a simple “grafting from” strategy. The ration of each segment can be controlled by the feed ratio of comonomers. These star-comb double crystalline copolymers are well-defined and expected to illustrate the influences of the polymer chain topology by comparing with their counterparts in linear-shaped, star-shaped, and linear-comb shape. The crystallization behaviors of PCL- b -PLLA copolymers with different architectures are investigated systematically by means of wide-angle X-ray diffraction, differential scanning calorimetry, and polarized optical microscopy analysis. It is shown that the comb branched architectures promote the crystallization behavior of each constituent significantly. Both crystallinity and melting temperature greatly raise from linear to comb-shaped copolymers. Compared to linear-comb topology, the star-comb shape presents some steric hindrance of the graft points, which decrease the crystallinity of scPCL- b -PLLA. Effects of copolymer composition and chain topology on the crystallization are studied and discussed.
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2016
·
IF 7.145
Xiaoyan Zhou,Qianqian Zheng,Changyong Wang,Jiake Xu,Jian-Ping Wu,Thomas Brett Kirk,Dong Ma,Wei Xue
The drug/gene codelivery is a promising strategy for cancer treatment. Herein, to realize the codelivery of docetaxel and MMP-9 siRNA plasmid efficiently into tumor cells, a star-shaped amphiphilic copolymer consisting of hyperbranched polyglycerol derivative (HPG-C18) and dendritic poly(l-lysine) (PLLD) was synthesized by the click reaction between azido-modified HPG-C18 and propargyl focal point PLLD. The obtained HPG-C18-PLLD could form the nanocomplexes with docetaxel and MMP-9, and the complexes showed good gene delivery ability in vitro by inducing an obvious decrease in MMP-9 protein expression in MCF-7 cells. The apoptosis assay showed that the complex could induce a more significant apoptosis to breast cancer cells than that of docetaxel or MMP-9 used alone. In vivo assay indicated that the codelivery strategy displayed a better effect on tumor inhibition. Moreover, HPG-C18-PLLD displayed lower toxicity as well as better blood compatibility compared to polyethylenimine PEI-25k, which may be the result of that HPG-C18-PLLD showed the comparative MMP-9 delivery ability in vivo compared with PEI-25k even if it showed the slight lower transfection efficiency in vitro. Therefore, HPG-C18-PLLD is a safe and effective carrier for the codelivery of drug/gene, which should be encouraged in tumor therapy.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Polymer Chemistry
·
2014
·Vol. 5
·期 15
·4580-4588
·
IF 5.368
Yang Wang,Bo Liu,Xue Wang,Wei Zhao,Dongtao Liu,Xinli Liu,Dongmei Cui
Catalyst systems obtained from the inexpensive, ligand-free and commercially available MgnBu2 and alcohols were used for the ring-opening polymerization (ROP) of ε-caprolactone (ε-CL) under mild conditions. The catalytic system of MgnBu2/Ph2CHOH showed very high activity as compared with the system of MgnBu2/Ph3COH, which applied a more bulky methanol derivative. Interestingly, in the presence of excess amount of alcohol (Ph2CHOH), i.e., varying the OH-to-Mg ratio in a wide range from 10 : 1 to 800 : 1, the system MgnBu2/Ph2CHOH still remained highly active, and produced up to 800 polycaprolactone (PCL) chains per Mg center, suggesting a “living immortal” polymerization mode. The molecular weights of the obtained PCLs are accurately controlled when the ratio of [CL]0/[Mg]0 changed from 500 to 8000 together with narrow molecular weight distributions. Moreover, diblock PCL-b-PLA copolymers with narrow PDIs have been facilely achieved. Furthermore, the allyl- and propargyl-functionalized diphenylmethanols could be employed as the chain transfer agents (CTA) in this system for in situ construction of allyl- and propargyl-functionalized PCLs that were facilely modified further to PCLs with multiple functionality as building blocks for amphiphilic and topological microstructured PCLs via coupling and click reactions.
研究领域:
高分子化学
·
材料科学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF PHARMACEUTICS
·
2011
·
IF 3.607
Wei Wu,Jing Liu,Shuqin Cao,Hong Tan,Jianshu Li,Fujian Xu,Xiao Zhang
A series of pH sensitive semi-interpenetrating polymer network (semi-IPN) structural hydrogels composed of poly(vinyl alcohol) (PVA) and 21-arm star poly[2-(dimethylamino)ethyl methacrylate] (star PDMAEMA) with different molecular weight were prepared. Riboflavin was used as a model drug to evaluate the drug loading capacities and drug release behaviors of the semi-IPN structural hydrogels. The molecular weight of the star PDMAEMA polymers was calculated by GPC, and the formation of semi-IPN structure was confirmed by FTIR and SEM. It was found that the molecular weight of star PDMAEMA has significant effect on the structure, swelling ratio and drug release behaviors of the semi-IPN hydrogel at different pH conditions. The results suggested that the PVA/star PDMAEMA-50,000 hydrogel exhibited highest swelling ratio and drug loading capacity. The pH-sensitive semi-IPN hydrogel based on star PDMAEMA could be a promising drug delivery system due to the controllable porous structure.
研究领域:
材料科学
·
药学
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）