FUEL
·
2024
·
IF 6.7
Xinjie Sun,Lingli Jia,Xinyuan Li,Shanrong Zhang,Yiting Wang,Mingwang Fan,Jun Xu
Wax precipitation causes numerous challenges in the transportation and refining of crude oil. Wax deposition can be decreased and the flowability of waxy crude oil in cold temperatures can be increased by addition of polymer additives in the crude oil. Sequentially well-structured polymers synthesized by reversibly additive fragment chain transfer (RAFT) polymerization enhance the capability to inhibit the growing of wax crystals. In this paper, star chain-transfer agents (star-CTA) was synthesized by esterifying polyol with a tri-thiocarbonate RAFT reagent. Then, poly octadecyl acrylate-maleic anhydride (POM) copolymers with linear and star structure (3, 4, 6 arms) were synthesized via RAFT polymerization. The chemical structures were then characterized using FT-IR, 1 H NMR and GPC approaches. The effects of star copolymers on wax crystallization and cold flowability were analyzed by DSC, XRD, polarized light microscopy and rheology. The transformation from lamellar to fibrous crystals and a decrease in fractal dimensions of crystal growth upon adding all polymers were observed through kinetics of isothermal crystallization and non-isothermal crystallization (NIC) using DSC. Upon further calculations, the crystallization activation energy of NIC increased from 34.40 kJ/mol to 63.22 kJ/mol with the increase of arms. Revealed by XRD, both of the relative crystallinity index and the grain size of crystals are reduced by polymers. Further, the growth along the x and z axes is suppressed, resulting in fibrous growth. The viscosity initially decreases and then increases as the number of arms of polymer increases, with 4-arms POM (4X-POM) reducing the viscosity by 64.63 %. The present work reveals the mechanism of inhibiting wax crystal growth by star polymers, providing valuable theoretical guidance for the practical application.
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DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2018
·Vol. 135
·期 21
·46312
·
IF 1.901
Yangyang Zhao,Fuwei Nian,Hao Pang,Jianheng Huang,Hongwei Zhao,Kun Wang,Bing Liao
Star-shaped superplasticizers, which incorporated polyol ester with unsaturated bond at their cores and bore comb-type structures as their arms were synthesized via esterification-copolymerization in aqueous phase from pentaerythritol, acrylic acid (AA), and isopentenyl oxy poly(ethylene glycol ether) (TPEG). The monomer ratios of AA and TPEG were varied and comonomer sodium methallyl sulfonate (SMAS) bearing short side chains was added to regulate the arm structure of star-shaped polycarboxylate superplasticizers (SPCEs). The effects of the SPCEs on cement paste were investigated and the cement dispersion as well as early hydration mechanism were explored. As a main result, SPCEs with SMAS and certain molar ratios for anchoring groups and PEO side-chains in their arm structure exhibited good paste dispersion and fluidity retention, which also delayed the early hydration process and prolonged both the initial and the final setting time. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135 , 46312.
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高影响因子
Polymer Chemistry
·
2018
·Vol. 9
·期 9
·1095-1108
·
IF 4.927
Xiaoqi Zhao,Wentao Wu,Jian Zhang,Wenxue Dai,Youliang Zhao
Multicomponent miktoarm stars with multifunctional Y junctions may provide us with new insights into their physicochemical properties and prospective applications. Considering the unique role of a gas stimulus in smart materials and the promising gradient-type properties induced by combined stimuli, this study aims at the synthesis, thermoresponsive and self-assembly behaviors of an O2-, redox-, thermo-, and pH-responsive 3-miktoarm star quarterpolymer. A robust method involving controlled polymerization, amine–thiol–ene conjugation and hydrolysis was developed to achieve a poly(N-isopropylacrylamide-co-4-(2-(2,2,2-trifluoroethylcarbamoyl)ethylthio)-2-(acrylamido)-N-(2-hydroxyethyl)butanamide)-arm-poly(ε-caprolactone)-arm-poly(acrylic acid) star. Owing to the changes in amphiphilicity, chemical composition and mutual interactions, a single stimulus or various stimuli combinations could lead to switchable LCSTs and morphological transformations. Upon increasing pH, O2 treatment and oxidation, the copolymer solution was liable to exhibit enhanced LCST due to the improved hydrophilicity. The star quarterpolymer could self-assemble into multicompartment vesicles (pH 3.0), vesicles (pH 5.9) and small micelle/vesicle mixtures (pH 10) at ambient temperature. Upon thermo, redox and O2 stimuli, the assemblies formed at different pHs could be further converted into some other morphologies such as compound micelles and nanocapsules with hollow caves. Our research affords a general route to synthesize MMSs with tailored Y junctions, and the combination of the O2 stimulus with other stimuli may potentially expand the scope of multi-triggered properties and applications of star copolymers.
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高影响因子
MATERIALS & DESIGN
·
2025
·
IF 7.9
Yu Ma,Bin Zhao,Guozhen Yan,Ting Zhou,Zhihua Xu,Zhihan Niu,Zhenghong Xu,Tongtong Zhang,Feng Shi
Nucleic acid dyes play important roles in the quantification and detection of nucleic acids by binding to nucleic acids. However, traditional nucleic acid dyes pose great environmental and economic challenges due to their high price, high toxicity, long dyeing time, low sensitivity and insufficient stability. To overcome these problems, we developed a new nucleic acid dye based on carbon dots, which were generated through hydrothermal synthesis with liquorice components as precursors and a system containing ethylenediamine. This new type of carbon dot can effectively replace traditional dyes and can be used to efficiently visualize DNA, RNA and plasmids via agarose gel electrophoresis. Then, we studied the interaction mechanism between carbon dots and nucleic acids by UV–visible spectroscopy, Fourier transform infrared spectroscopy and circular dichroism spectroscopy. The interaction between the carbon dots and nucleic acids mainly occurred through groove binding and was accompanied by a slight electrostatic interaction. Carbon dots-based nucleic acid dyes, with their low cost, simple synthesis process and high stability, have opened a new path for the field of nucleic acid detection. Its research and development not only promote the frontier progress of biological science and medicine but also introduces innovative strategies and tools for scientific research and clinical practice.
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高影响因子
Journal of Environmental Chemical Engineering
·
2025
·
IF 7.2
Rongxin Zhao,Hengtong Xia,Shaojie Gong,Jiawei Yang,Jie Wang,Xiaoshuang Yin,Ying Liu,Wenzhong Yang,Hui Xu
This study presents a green scale inhibitor design paradigm through the precision synthesis of β-cyclodextrin-grafted poly (tert-butyl acrylate) (P t BA) star polymers via atom transfer radical polymerization (ATRP), followed by hydrolysis to yield poly (acrylic acid) (β-CD-PAA). Structural characterization by FTIR 1 H NMR and GPC confirmed well-defined architectures with tunable PAA arm lengths ( Mₙ = 12–58 kDa, Đ = 1.05–1.15). The star topology demonstrated exceptional dual functionality: (1) Scale inhibition – achieving 86.36 % CaCO 3 inhibition at 55 mg/L and 96.87 % CaSO 4 inhibition at 6 mg/L, outperforming linear polyacrylic acid by 15–32 % efficiency; (2) Scale dissolution – maintaining excellent conductivity recovery via colloidal stabilization. Systematic evaluation revealed robust performance across harsh conditions (pH 4–12, 60–90 °C). Multiscale characterizations (i.e., SEM, XRD) unveiled a dual mechanism: multidentate Ca 2+ chelation and 3D steric hindrance that distorted crystal nuclei and promoted metastable vaterite formation. This work establishes star-shaped polysaccharide derivatives as next-generation scale inhibitors, offering a sustainable alternative to phosphorus-based inhibitors while advancing molecular-level understanding of topology-dependent scaling control.
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高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2016
·Vol. 26
·期 26
·4643-4652
·
IF 11.382
Zhenguo Wang,Zuojia Li,Xiaopeng Xu,Ying Li,Kai Li,Qiang Peng
A series of star-shaped small molecular cathode interlayer materials are synthesized for PTB7:PC 71 BM based polymer solar cells (PSCs), comprising neutral amino groups, quaternary ammonium ions, amino N-oxides, and sulfobetaine ions as pendant polar functionalities, respectively. For the first time, the effect of these different pendant functional groups with or without mobile counterions on the cells' photovoltaic properties is investigated in detail. A large improvement in device performance is observed by inserting these cathode interfacial layers (CILs) between the PTB7:PC 71 BM active layer and the Al electrode. The CILs could effectively lower the work function of the Al cathode, increase the built-in potential, and decrease the series resistance of the related PSCs. poly(9,9-dioctylfluorene-co- N -[4-(3-methyl-propyl)]-diphenylamine) with pendant quaternary ammonium ions shows the best cathode modification ability, giving rise to the highest power conversion efficiency of 10.1%, even better than that of the typical poly[(9,9-bis(3′-( N , N -dimethylamino)propyl)-2,7-fluorene)- alt -2,7-(9,9-dioctylfluorene)] based device. The design strategy and structure–property relationships concluded in this work will be helpful to develop more efficient cathode interface materials for high-performance PSCs in the future.
研究领域:
材料科学
·
能源科学
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高影响因子
BIOMATERIALS
·
2014
·
IF 8.312
Dong Ma,Qian-Ming Lin,Li-Ming Zhang,Yuan-Yuan Liang,Wei Xue
The co-delivery of drug and gene has become the primary strategy in cancer and other disease therapy. To co-deliver hydrophobic drug and functional gene efficiently into tumor cells, a star-shaped copolymer (PP-PLLD-Arg) with a photochemical internalization effect consisting of a porphyrin (PP) core and arginine-functionalized poly( l -lysine) dendron (PLLD-Arg) arms has been designed, and used to co-deliver docetaxel (DOC) and MMP-9 shRNA plasmid for nasopharyngeal cancer therapy. It was found that PP-PLLD-Arg/MMP-9 nanocomplex showed the photo-enhanced gene transfection efficiency in vitro , and could mediate a significant reduce of MMP-9 protein expression in HNE-1 cells. For co-delivery analysis, the obtained PP-PLLD-Arg/DOC/MMP-9 complexes could induce a more significant apoptosis than DOC or MMP-9 used only, and decreased invasive capacity of HNE-1 cells. Moreover, the star-shaped copolymer exhibited better blood compatibility and lower cytotoxicity compared to PEI-25k in the hemolysis and MTT assays , and also showed a good biocompatibility in vivo . Therefore, PP-PLLD-Arg with suited irradiation is a promising non-toxic and photo-inducible effective drug and gene delivery strategy, which should be encouraged in tumor therapy.
研究领域:
药学
·
生物医学工程
·
癌症研究
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DOI
PubMed
高影响因子
POLYMER DEGRADATION AND STABILITY
·
2021
·
IF 5.03
Youlin Qin,Mingchao Li,Tuankang Huang,Chunhui Shen,Shanjun Gao
In this paper, a star-shaped char forming agent BTETP containing phosphorus and nitrogen is synthesized and characterized in the paper. It is compounded with ammonium polyphosphate (APP) to form an intumescent flame-retardant system. The stable star-shaped structure is constructed, and the insulating char layer is formed on the surface of the polymer matrix by the synergistic effect between phosphorus and nitrogen, thus, the high-performance flame retardant PP is obtained. Its flame retardancy and thermal stability are studied by limiting oxygen index (LOI), vertical combustion test (UL-94), cone calorimetry (CCT), and thermogravimetric analysis (TGA). With only a 20 wt% addition of BTETP/APP (1:2), the PP composite can reach the UL-94 v-0 level, while the peak heat release rate (PHRR), total heat release rate (THR), and average mass loss rate (AV-MLR) are significantly reduced compared with pure PP, showing higher fire safety. Moreover, the residue at 800 °C can reach as high as 9%, indicating that the loading of BTETP/APP is conducive to promoting carbonization of the degradation products of PP to generate more char. In addition, the synergistic effect and the flame retardant mechanism are studied and discussed. This study provides a program for the synthesis of flame retardants with a high-performance and effectively avoids the problem existing in traditional flame retarding approaches.
研究领域:
材料科学
·
化学工程
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高影响因子
SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS
·
2026
·
IF 6.6
Wei Ma,Hongyan Yang,Xinyue Ma,Jiao Huang,Li Chen,Atsushi Takahara
The development of polymer prodrugs with well-defined architectures capable of forming stable nanomicelles is important for achieving precise and efficient drug delivery. Compared with conventional linear systems, star-shaped copolymer prodrugs offer enhanced micellar stability owing to their covalently tethered architecture. However, many existing synthetic approaches rely on transition-metal catalyzed polymerization and customized monomers, which limit their sustainability and practical applicability. Herein, we report a pH-responsive doxorubicin (DOX)-conjugated benzaldehyde-functionalized star-shaped copolymer synthesized via an environmentally benign metal-free atom transfer radical polymerization (ATRP) strategy. A hydroxyl-functionalized star-shaped copolymer scaffold was first prepared from readily available monomers and subsequently modified to introduce pendant benzaldehyde groups, enabling DOX conjugation through acid-labile imine linkages. This approach affords well-controlled polymer architectures while avoiding transition-metal residues and the need for pre-functionalized monomers. The resulting DOX-conjugated star-shaped copolymers form unimolecular micelles with high colloidal stability and exhibit pH-triggered drug release under acidic conditions. In vitro studies further demonstrate effective cellular internalization and a moderated cytotoxic profile toward human large-cell lung carcinoma (H460) cells, supporting the functional viability of this micellar system as a polymer prodrug delivery platform.
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DOI
PubMed
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 68
·55048-55058
·
IF 3.84
Aizhao Pan,Shao Yang,Ling He
Polyhedral oligomeric silsesquioxane (POSS) tethered fluorinated diblock copolymers including linear-shaped ap-POSS–PMMA-b-PDFHM and star-shaped s-POSS–(PMMA-b-PDFHM)16 are synthesized by octakis(dibromoethyl)POSS (POSS-(Br)16) and aminopropylisobutyl POSS (ap-POSS) initiating methylmethacrylate (MMA) and dodecafluoroheptylmethacrylate (DFHM). In THF solution, both diblock copolymers could self-assemble into 200 nm core/shell micelles with a POSS/PDFHM core and 70–80 nm PMMA shell. These micelles are able to produce typical films with a fluorine-rich top-surface and POSS-gathered sub-surface. Although PDFHM segments and POSS cages are competitively migrating onto the film surface, the migration of the PDFHM segments is actually improved by the POSS cages. Comparatively, the surface of the ap-POSS–PMMA-b-PDFHM film is much more rough and fluorine-rich than the s-POSS–(PMMA-b-PDFHM)16 film, therefore, the ap-POSS–PMMA-b-PDFHM film has higher viscoelasticity and higher oleophobicity, but a little lower hydrophobicity than the s-POSS–(PMMA-b-PDFHM)16 film. The hydrophobic application of both linear- and star-shaped topologies to glass, cotton fabric and stone substrates reveals that the treated samples exhibit superhydrophobicity for the cotton fabric (>150°) and obvious hydrophobicity for the stone and glass (>135°) in terms of resistance to water and other liquids like coffee, milk, coke and green tea. It is believed that the properties of self-assembled films and the hydrophobic applications are related closely to the topologies of block copolymers.
研究领域:
高分子化学
·
材料科学
·
表面科学
·
纳米技术
·
功能材料
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DOI
高影响因子
ACS Applied Energy Materials
·
2021
·
IF 6.024
Jingyu Ma,Xiaoyan Ma,Chengchen Luo,Xinghua Guan,Fang Chen,Yibo Chen,Jingwen Tu
The low ionic conductivity and mechanical strength are important factors impeding the application of solid polymer electrolytes. Herein, we design synthesize an organic/inorganic hybrid star-shaped polymer of octa(poly(methyl methacrylate)–poly(poly(ethylene glycol) methyl ether methacrylate) cage oligomeric silsesquioxanes (POSS–(PMMA–PPEGMEM)8) by one-step free atom transfer radical polymerization (ATRP), and compound with Li6.4La3Zr1.4Ta0.6O12 (LLZTO) to prepare a composite polymer electrolyte membrane (LP-CPEM). The star-shaped structure of the POSS–(PMMA–PPEGMEM)8 induced by octachloropropyl polyhedral cage oligomeric silsesquioxane (OCP-POSS) is beneficial to reduce the crystallinity of polymer and increase the movement of the polymer chain to form a continuous interconnected ion migration channel. The LLZTO fillers in the LP-CPEM could simultaneously hinder the orderly arrangement of polymer chains and provide other ion transport paths to increase the ion conductivity of LP-CPEM. The LP-CPEM with 7.5 wt % LLZTO has higher ionic conductivity of 3.8 × 10–4 S cm–1 at 30 °C and high mechanical strength (5.2 MPa). Additionally, Li/Li symmetric cells demonstrate stable constant current charging/discharging during 1000 h at 0.1 mA cm–2, and the all-solid-state batteries fabricated by the LP-CPEM exhibit good cyclic stability. It is promising for the development of next-generation high-safety all-solid-state lithium metal batteries.
研究领域:
材料科学
·
电化学
·
储能技术
·
聚合物化学
·
固态电池
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DOI
高影响因子
Science Advances
·
2021
·Vol. 7
·期 28
·
IF 14.143
Qi Cao,Yongjiang Li,Hong Zhang,Jiabao Yang,Jian Han,Ting Xu,Shuangjie Wang,Zishuai Wang,Bingyu Gao,Junsong Zhao,Xiaoqiang Li,Xiaoyan Ma,Shaik Mohammed Zakeeruddin,Wei E. I. Sha,Xuanhua Li,Michael Grätzel
Stabilizing high-efficiency perovskite solar cells (PSCs) at operating conditions remains an unresolved issue hampering its large-scale commercial deployment. Here, we report a star-shaped polymer to improve charge transport and inhibit ion migration at the perovskite interface. The incorporation of multiple chemical anchor sites in the star-shaped polymer branches strongly controls the crystallization of perovskite film with lower trap density and higher carrier mobility and thus inhibits the nonradiative recombination and reduces the charge-transport loss. Consequently, the modified inverted PSCs show an optimal power conversion efficiency of 22.1% and a very high fill factor (FF) of 0.862, corresponding to 95.4% of the Shockley-Queisser limited FF (0.904) of PSCs with a 1.59-eV bandgap. The modified devices exhibit excellent long-term operational and thermal stability at the maximum power point for 1000 hours at 45°C under continuous one-sun illumination without any significant loss of efficiency.
研究领域:
材料科学
·
高分子科学
·
光伏技术
·
纳米技术
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DOI
高影响因子
危险品化学品经营许可证（带存储）