Polymer Chemistry
·
2013
·Vol. 5
·期 6
·1930-1937
·
IF 5.231
Dan Li,Haolong Li,Lixin Wu
A series of hybrid supramolecular star polymers (SSPs) consisting of a polyoxometalate EuW10O369− (EuW10) core and different length of polystyrene arms have been fabricated by a “core-first” method, in which the anionic EuW10 clusters were firstly encapsulated by cationic molecules with trithioester terminal groups and subsequently polystyrene arms were grafted by reversible addition–fragmentation chain-transfer (RAFT) polymerization. The SSPs exhibit structurally dependent self-assembly behaviours in solution, at the air–water interface and solid state. It was found that the SSPs with short arms form large assemblies with a diameter over 100 nm in chloroform, while those with long arms tend to be mono-dispersed. Meanwhile, the distance between the EuW10 cores of adjacent SSPs in Langmuir monolayers and casting films can be precisely adjusted by PS arms, which leads to a tunable colour purity of EuW10 luminescence. This tight structure–property relationship enables the polyoxometalate-cored SSPs to act as potential building blocks for the construction of hybrid polymer materials with controllable functions.
研究领域:
材料科学
·
高分子化学
·
超分子化学
·
纳米材料
·
发光材料
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DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 112
·111217-111225
·
IF 3.289
Sijie Zhao,Huiru Yang,Cai Zuo,Lu Sun,Liwei Ma,Hua Wei
Star-shaped polymers are attractive as drug carriers due to the integration of relatively easy synthesis compared to the preparation of hyper-branched dendrimers and their potential ability to form unimolecular nanoparticles with enhanced stability to survive the high dilution-associated deformation and subsequently premature drug release in the body fluids and blood during circulation. Clearly, the star structure exerts a significant effect on their bioproperties and potential applications. In this study, three star-shaped amphiphilic copolymers with the same polymer compositions but different star structures were synthesized to investigate the effect of star architecture on their properties as well as potential applications as drug carriers. Three different branched alcohols, 2-(hydroxymethyl) propane-1,3-diol, pentaerythritol and dipentaerythritol with 3, 4, and 6 respective hydroxyl groups were chosen as the starting core to generate the target star-shaped amphiphilic block copolymers composed of hydrophobic poly(ε-caprolactone) (PCL) and hydrophilic poly(oligoethyleneglycol methacrylate) (POEGMA) with 3, 4, and 6 corresponding star arms by a combination of ring-opening polymerization (ROP) and atom transfer radical polymerization (ATRP). Dynamic light scattering (DLS) measurements and pyrene fluorescence probe technique confirmed the capability of the resultant star-shaped amphiphilic copolymers to form unimolecular micelles with average diameters smaller than 50 nm in an aqueous phase. A comparison of the drug loading capacity revealed that the micelles of 4-star-PCL–POEGMA (4s-PCL–POEGMA) exhibited the highest drug loading content (DLC) of all the three formulations. More importantly, in vitro doxorubicin (DOX) release study showed unique pH-mediated drug release behaviors, i.e., dramatically accelerated release at pH 6.0 but a much slower profile at pH 7.4, from these generally recognized “pH-insensitive” 4-arm star-shaped micelles. An acid-triggered degradation and an acid–base titration were performed to further reveal that such interesting pH-responsive drug release behaviors were attributed primarily to the hydrophilic corona of OEG brushes. This study is believed to provide a new insight into the structure–bioproperties relationship of star-shaped polymers, thus should be useful for the future design and development of novel star-shaped polymers for controlled drug delivery.
研究领域:
高分子药剂学
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纳米医学
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药物控释
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生物材料
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药剂学
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肿瘤治疗
·
纳米载体
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DOI
高影响因子
POLYMER
·
2017
·
IF 3.684
Shilin Zhang,Tianyang Xu,Shengchao Chai,Liying Zhang,Lixin Wu,Haolong Li
Microporous films with tunable honeycomb structures were fabricated based on the self-assembly of a series of clusto-supramolecular star polymers (CSPs) guided by breath figure templates. The CSPs consist of a hydrophilic polyoxometalate cluster core and several hydrophobic polystyrene arms that are electrostatically connected to the core, in which three Keggin-type polyoxometalate clusters [CoW 12 O 40 ] 6- , [SiW 12 O 40 ] 4- and [PW 12 O 40 ] 3- were used as the cores. The dynamic bonding character endows CSPs a rearrangeable amphiphilic conformation that facilities them to accumulate at the oil/water interface to stabilize water droplets. By precisely adjusting the arm number and arm length of CSPs, we revealed the relationship between the structure and the film-forming behavior of CSPs. Regular pores with a small diameter as low as 260 nm were obtained by optimizing the structure of CSPs. Moreover, the CSPs could act as morphological modifiers to efficiently improve the microporous regularity of polystyrene films, even at a low CSP content of 0.8 wt%. To the best of our knowledge, this is the first work using supramolecular star polymers to fabricate microporous films by the breath figure method, which not only introduces a new film-formation material, but also provides a facile way to incorporate inorganic functional components into microporous polymer films .
研究领域:
高分子科学
·
材料化学
·
纳米结构制备
·
软物质物理
·
功能材料
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DOI
高影响因子
Materials Today Communications
·
2023
·
IF 3.8
Ze-Zhong Lin,Yan Wang,Xiao-Bo Yang,Shang-Rong Yan,Yu Chen,Hai-Chao Li,Gang Wang
Besides the good flexibility and extensibility, plasticized soft poly(vinyl chloride) (PVC) possessing the extra characteristics of high modulus, tensile strength and toughness are desired for wider applications. Herein, a series of three-arm star copolymers possessing the hard polylactide (PLA)-rich core and the soft poly(ε-caprolactone)-rich (PCL) shell (S 3 -PLA-PCL) were prepared, which were used as the plasticizers for the preparation of soft PVCs. The monomer ratio of ε-caprolactone to lactide (LA), the average polymerization degree of LA and the type of LA (racemic or L type) were optimized to achieve the best mechanical performance of soft PVCs. With the similar elongation at break, S 3 -PLA-PCL plasticized PVC exhibited higher modulus, strength and toughness than PVCs plasticized by the corresponding linear PLA-PCL and other traditional low molar-mass and polymeric plasticizers without hard core. This pointed out the importance of the star topology and the hard PLA-rich core of S 3 -PLA-PCL in strengthening soft PVCs. The transparency of PVC plasticized by S 3 -PLA-PCL was similar to the neat PVC and PVCs plasticized by the traditional plasticizers. Migration stability tests demonstrated that S 3 -PLA-PCL had excellent migration resistance in PVC matrix. Moreover, both PLA and PCL are sustainable, biocompatible and biodegradable, hence, the as-prepared S 3 -PLA-PCLs can be called as high-performance, green polymeric plasticizers for PVC plastics.
研究领域:
材料科学
·
高分子化学
·
环境科学
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产品关联
DOI
高影响因子
JOURNAL OF POLYMERS AND THE ENVIRONMENT
·
2022
·Vol. 30
·期 8
·3121-3128
·
IF 4.705
He Jing,Yu Tao,Yang Weidong,Li Yan
Biodegradable four-arm star-shaped poly(lactic acid) (4sPLA) was synthesized from l -Lactic acid ( l -LA) and pentaerythritol (PENTA), and the polymerization kinetics was studied. The effects of reaction time, reaction temperature and molar ratio on the polymerization of 4sPLA were discussed. The molecular structure of 4sPLA was characterized by Fourier transform infrared spectroscopy (FTIR) and 1 H nuclear magnetic resonance spectra ( 1 H-NMR). The results showed that the optimum reaction conditions were as follows: the molar ratio of l -LA to PENTA was 12:1, and the polymerization reaction occurred at 160 ℃ for 5 h. Gel permeation chromatography method was used to determine the polymerization kinetics of 4sPLA consistent with the first-order reaction kinetics.
研究领域:
材料科学
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化学工程
·
生物医学材料
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产品关联
DOI
高影响因子
Soft Matter
·
2015
·Vol. 11
·期 15
·2945-2951
·
IF 4.029
Yong Shen,Shusheng Zhang,Yaoming Wan,Wenxin Fu,Zhibo Li
A second or fourth generation dendrimer with primary amine as the peripheral terminal group was first synthesized via Michael addition and thiol–yne addition. A series of star-shaped polypeptides was synthesized by ring opening polymerization (ROP) of γ-(2-(2-methoxyethoxy)ethyl) L-glutamate (L-EG2Glu) N-carboxyanhydride (NCA) using the amine group terminated dendrimer as the initiator. Taking advantage of the well-defined dendrimer and ROP, the arm number and arm length can be easily controlled. These star-shaped poly(L-EG2Glu) can spontaneously form hydrogels instead of micelles in water at low concentration. The critical gelation concentration (CGC) and hydrogel strength displayed a stronger dependence on arm numbers than the arm length under similar conditions. These properties can be easily modulated by varying the poly(L-EG2Glu) arm length and arm number. The hydrogels showed shear thinning and rapid recovery properties. TEM and AFM characterization revealed that the hydrogel networks were constituted by entangled and branched fibrils.
研究领域:
生物材料学
·
高分子化学
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产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 107
·88382-88391
·
IF 3.84
Chunhua Wang,Feng Hu,Kejian Yang,Tianhui Hu,Wenzhi Wang,Rusheng Deng,Qibin Jiang,Hailiang Zhang
A novel star-branched nylon 6 with hexafunctional cyclotriphosphazene core was synthesized using hexa(4-carboxylphenoxy)cyclotriphosphazene (HCPCP) with six carboxyl groups as multifunctional agent in the hydrolytic ring-opening polymerization of ε-caprolactam, and then used for the investigation of mechanical properties, crystallization and rheology behaviors. Star-branching structure and molecular weight have great effects on its properties. Compared with linear nylon 6, star-branched nylon 6 has lower relative viscosity and higher melt flow rate while its mechanical properties can be almost retained by the use of star-branching and an appropriate molecular weight. Research on crystallization behavior indicates that the degree of crystallinity (Xc) of star-branched nylon 6 decreases slightly, but its crystal structure still belongs to α form. The peak crystallization temperature (Tc) and crystallization rate (1/t1/2) of star-branched nylon 6 are significantly higher than that of linear nylon 6 because of heterogeneous nucleation induced by HCPCP core, which is beneficial for the use of rapid molding process. As the molecular weight increases, the Tc and 1/t1/2 of star-branched nylon 6 first increase and then decrease. Capillary rheometer measurement exhibits that the shear viscosity of star-branched nylon 6 decreases with decreasing molecular weight, and the shear viscosity of star-branched nylon 6 with an appropriate molecular weight shows a low value and little or no sensitivity to shear rate and temperature. Such rheology behavior allows for processing at low temperature and low pressure and reduces system cost.
研究领域:
高分子化学
·
材料科学
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产品关联
DOI
高影响因子
REACTIVE & FUNCTIONAL POLYMERS
·
2015
·
IF 2.515
Li-Ping Wang,Ke-Yang Yin,Guang Li,Qian Liu,Ai-Xia Deng,Hui-Yan Ma
Two types of star polystyrene (SPS) were synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization: three-arm star polystyrene (TSPS) and five-arm star polystyrene (FSPS). Honeycomb-structured porous films were fabricated by drop-casting of the SPS solutions on glass substrates . The regular honeycomb-patterned porous films were successfully constructed from the SPS solution casting process , and the pore diameter increased with the molecular weight of the SPS enhanced at appropriate molecular weight range. Furthermore, rhodamine B (RhB) was loaded into SPS to endow the microporous film with fluorescence. The RhB-loaded SPS film exhibits a strong and uniform red emission image.
研究领域:
材料科学
·
化学工程
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产品关联
DOI
高影响因子
MATERIALS LETTERS
·
2016
·
IF 2.437
Xinyu Peng,Yixin Zhang,Ying Chen,Sai Li,Bin He
A well-defined miktoarm star copolymer (μ-PEG-PCL-PLLA) was synthesized and the crystallization behavior of the copolymers was investigated. The structure of copolymer was confirmed by 1 H NMR, the molecular weight and molecular weight distribution were studied by GPC . XRD and POM were used to study the crystallization behavior of the miktoarm star copolymers. The XRD spectra showed that the miktoarm star copolymer showed low crystallinity for the joint of terminal, which limited the mobility of polymeric chains. The POM photographs revealed that PCL segments formed spherulites with PLLA crystalline grains as nucleus due to the good compatibility between PCL and PLLA.
研究领域:
材料科学
·
高分子化学
·
生物医学材料
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DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2021
·
IF 8.742
Yu Pan,Kang Jiang,Xingrun Sun,Siyu Ma,Yat-Ming So,Hongwei Ma,Xiaoming Yan,Ning Zhang,Gaohong He
Anion exchange membrane (AEM) with high ionic conductivity and good stability is of vital importance for developing high-performance alkaline anion-exchange membrane fuel cell (AEMFC). In particular, the performance of AEM largely depends on the microstructure of the basic polymer material. Herein, we have developed a novel strategy to fabricate the AEMs, featuring a star topological structure, via living anionic polymerization and the subsequent functionalization. Thanks to the introduction of well-defined amphiphilic block structure, a distinct micro-phase separation was observed in the synthesized AEMs (AEM-SCP) which were based on star-shaped block copolymers. In comparison to the AEM-LCP membranes based on linear block copolymers, the AEM-SCP membranes exhibited relatively lower water uptake and swelling ratio, but much higher hydroxide conductivity (at 80 °C, 68.1 mS cm −1 for AEM-SCP-3 vs. 38.1 mS cm −1 for AEM-LCP). This is attributed to the efficient aggregation of ionic groups via employing star-shaped block copolymers, which can result in the formation of continuous ion-conducting channels and the facilitated ionic conduction in the AEMs. Furthermore, compared with the AEM-LCP membrane, the dimensional and alkaline stability of the resultant AEM-SCPs have been significantly enhanced.
研究领域:
材料科学
·
化学工程
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DOI
高影响因子
ACS Nano
·
2019
·
IF 13.903
Xuexiang Han,Ying Xu,Yiye Li,Xiao Zhao,Yinlong Zhang,Huan Min,Yingqiu Qi,Gregory J. Anderson,Linhao You,Yuliang Zhao,Guangjun Nie
Combining informative imaging methodologies with effective treatments to destroy tumors is of great importance for oncotherapy. Versatile nanotheranostic agents that inherently possess both diagnostic imaging and therapeutic capabilities are highly desirable to meet these requirements. Here, a simple but powerful nanoplatform based on polydopamine-coated gold nanostar (GNS@PDA), which can be easily diversified to achieve various function extensions, is designed to realize functional and anatomical imaging-guided photothermal oncotherapy. This nanoplatform intrinsically enables computed tomography/photoacoustic/two-photon luminescence/infrared thermal tetramodal imaging and can further incorporate fibroblast activation protein (FAP, a protease highly expressed in most of tumors) activatable near-infrared fluorescence imaging and Fe3+-based magnetic resonance imaging for comprehensive diagnosis. Moreover, GNS@PDA exhibits excellent photothermal performance and efficient tumor accumulation. Under the precise guidance of multimodal imaging, GNS@PDA conducts homogeneous photothermal ablation of bulky solid tumors (∼200 mm3) in a xenograft mouse model. These results suggest great promise of this extendable nanoplatform for cancer theranostics.
研究领域:
生物医学工程
·
纳米技术
·
癌症治疗
·
医学成像
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF PHYSICAL CHEMISTRY B
·
2026
·
IF 3.2
Xinfeng Lin,Linquan Wang,Zhengying Qin,Lifeng Huang,Long Zheng,Ziwei Li,Shaorong Lu
With the development of contemporary electronic devices toward miniaturization and integration, polymer composites with efficient heat dissipation are in increasing demand for thermal management. In this study, a star-shaped castor-oil-based modifier (CO-IPMSA) was synthesized and grafted onto boron nitride (BN) to obtain modified BN (ICBN). The resulting ICBN/natural rubber (NR) composites exhibit a tensile strength of 20.44 MPa, an elongation at break of 1451.99%, and a thermal conductivity of 0.933 W·m–1·K–1, corresponding to increases of 19.18%, 76.74%, and 55.76%, respectively, compared with the BN/NR composite (17.15 MPa, 821.53%, and 0.599 W·m–1·K–1). Molecular dynamics (MD) simulations were conducted to quantify interfacial interactions and microstructural characteristics (e.g., binding energy and fractional free volume), thereby providing mechanistic insight into the improved compatibility after modification.
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产品关联
DOI
PubMed
高影响因子
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