MACROMOLECULES
·
2018
·
IF 5.914
Wangmeng Hou,Yuan Feng,Baohui Li,Hanying Zhao
A combined computer simulation and experimental study on coassembly of poly(2-(dimethylamino)ethyl methacrylate)-block-polystyrene (PDMAEMA-b-PS) block copolymers and PS brushes on silica particles was performed. PS brushes on silica particles at two different grafting densities were prepared by the “grafting to” approach, and PDMAEMA-b-PS block copolymers with different molecular weights and compositions were synthesized by reversible addition–fragmentation chain transfer polymerization. In THF/methanol mixtures, block copolymer chains and PS brushes coassemble into surface micelles (s-micelles), with collapsed PS cores and PDMAEMA coronae. Meanwhile, block copolymer chains are able to self-assemble into block copolymer micelles (b-micelles). Computer simulation results and experimental results indicate that block copolymer concentration, PS and PDMAEMA block lengths, and PS grafting density exert significant influences on the coassembly process. In low BCP concentration regime, the average size of s-micelles increases with BCP concentration and keeps unchanged at high concentration. The PS block length has a significant influence on the size of s-micelles. The average size increases with an increase in PS block length. For a BCP with long solvophilic PDMAEMA block, it is energy favorable to self-assemble into b-micelles, but to coassemble into s-micelles. With an increase in PDMAEMA block length, the morphology of the s-micelles changes from wormlike/spherical structures to spherical structures and to smaller spherical structures. The average size of the s-micelles coassembled by PS brushes at a lower grafting density is smaller than those coassembled by PS brushes at a higher grafting density.
研究领域:
材料科学
·
高分子化学
·
计算机模拟
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产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2019
·Vol. 136
·期 18
·47405
·
IF 2.188
Guorong Qiu,Wenshi Ma,Yuanqi Jiao,Li Wu
Low-dielectric-constant aromatics, homopolyimide and copolyimide, were introduced. Homopolyimides were prepared by pyromellitic dianhydride (PMDA) as an anhydride monomer and 4,4′-oxydianiline (ODA), 2,2-bis[4-(4-aminephenoxy)phenyl]propane, 1,4-bis(4-aminophenoxy)benzene, or 1,3-bis(4-aminophenoxy)benzene as an amine monomer. The copolyimides were prepared with PMDA as an anhydride monomer, ODA as an amine monomer with the addition of 2,2-bis[4-(4-aminephenoxy)phenyl]propane, 1,4-bis(4-aminophenoxy)benzene, or 1,3-bis(4-aminophenoxy)benzene as another amine monomer. The polyimides were well characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, thermomechanical analysis, dielectric measurements, and tensile testing. The homopolyimide and copolyimides showed lower dielectric constants than the homopolyimide formed by ODA and PMDA. The results also indicate that the interchain distance, the quantities of phenyl ether, and the position of the substitute are factors that not only affected the thermal performance of polyimide by improving the molecular flexibility but also reduced the dielectric constant of polyimide by increasing the free volume of the molecular chain and decreasing the polarization points per unit volume. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136 , 47405.
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
POLYMER ENGINEERING AND SCIENCE
·
2025
·
IF 3.2
Haohao Hou,Yu Xue,Meng Zhang,Xin He,Hongfu Zhou,Liyang Zhang
Polypropylene homopolymer (PPH) is a highly practical and widely utilized thermoplastic polymer that finds extensive applications in automotive components, piping systems, and constructed materials. Although PPH has merits such as low cost, versatility, and exceptional corrosion resistance, its low toughness limits application in specialized engineering sectors such as high-pressure piping, aerospace components, and cryogenic environments. In this paper, the toughness of PPH was improved by blending with polypropylene block copolymer (PPB) and β nucleating agent (NP-328). The room temperature impact strength of PPH containing 30% PPB and 0.2% NP-328 was increased by 4.4 times, and its low-temperature elongation at break was improved by 87%, compared to those of the pure PPH sample. Furthermore, this paper investigated the crystallization behaviors of PPH/PPB(70/30) with varying amounts of NP-328, using crystallization kinetics studies for analysis. The crystallization rate of PPH/PPB (70/30) systems gradually adding the amounts of NP-328 improved significantly. At 140°C, the half-crystallization time of the PPH/PPB (70/30) containing 0.2% NP-328 decreased by 14.5 min compared with that of PPH/PPB (70/30) without NP-328. The high-toughness PPH material developed in this work exhibits significant potential for application across a variety of industries, including automotive manufacturing, home appliance production, and packaging sector, among others. Highlights IS of polypropylene homopolymer (PPH) increased from 19.1 to 103.2 kJ/m2. Crystallinity of β in PPH/polypropylene block copolymer (PPB) growed to 26.8%. Low temperature toughness of PPH increased by about two times. The t1/2 of 70PPH/30PPB/0.2β was 14.5 min shorter than 70PPH/30PPB at 140 °C.
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
iScience
·
2024
·
IF 4.6
Zhiyong Wu,Jiacheng Luo,Luyang Li,Qingshu Dong,Xiaohui Zhang,Zili Li,Yadong Liu,Shengxiang Ji,Weihua Li,Yan Zhang,Shisheng Xiong
Directed self-assembly (DSA) lithography has demonstrated significant potential in fabricating integrated circuits. However, DSA encounters limited processing windows due to the requirement for precise matching between the period of block copolymers (BCPs) and graphoepitaxy templates. We propose a binary BCP/homopolymer blending strategy to manipulate the self-assembly behavior and the processing window of graphoepitaxy DSA in contact hole shrinking. By carefully tailoring the blending rates of poly(methyl methacrylate) (PMMA) with different molecular weights in cylindrical polystyrene- b -poly(methyl methacrylate) (PS- b -PMMA), we manipulate the period and morphology of BCP/homopolymer self-assembly. Specifically, we employ BCP/homopolymer blending to fine-tune the critical dimension (CD) of contact holes with PS-affined topographical templates. Subsequent pattern transferring is achieved by selectively etching defect-free shrinkable cylinders as hard masks. Furthermore, self-consistent field theory (SCFT) simulation was employed to explore the self-assembly of BCP/homopolymer blending in confined cylindrical space and the results were in good consistency with the experimental results.
研究领域:
材料科学
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纳米技术
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产品关联
DOI
PubMed
高影响因子
POLYMER
·
2020
·
IF 4.231
Ke Wang,Qi Liu,Guiyan Liu,Yongfei Zeng
The study of thermoresponsive homopolymers has attracted great attention due to their broad application value. Herein, a series of novel thermoresponsive homopolymers of poly[oligo(ethylene glycol) (acyloxy) methacrylate]s containing oligo(ethylene glycol) (OEG) units and substituent groups of ester have been designed and prepared by RAFT polymerization . The solution properties of these polymers have been investigated in detail, which indicate that most of them exhibit lower critical solution temperature (LCST) in water and upper critical solution temperature (UCST) in alcohols, and their LCST-type or UCST-type cloud point temperature ( T CP L or T CP U ) is closely related to the OEG units and ester groups. Furthermore, the parameters affecting the thermoresponse of these polymers including polymerization degree (DP) and concentration have also been investigated. The present work not only discovers a series of novel thermoresponsive polymers, but also has certain guiding significance on the understanding of molecular structure and thermoresponsive property relationships, which is useful for the design of new thermosensitive polymers.
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
CHINESE JOURNAL OF POLYMER SCIENCE
·
2019
·Vol. 38
·期 4
·349-356
·
IF 2.804
Yang Bo,Du Jian-Zhong
Noninvasive ultrasound is a more effective strategy for on-demand drug delivery of polymeric nanoparticles than many other stimuli. However, the preparation of ultrasound-responsive homopolymer nanoparticles is still very challenging. In this study, we disclose the regulating factors of ultrasound responsiveness of homopolymer nanoparticles and the disaggregation behavior of homopolymer nanoparticle aggregates. Homopolymer nanoparticles such as vesicles and large compound micelles (LCMs) are self-assembled from poly(methoxyethyl methacrylate) (PMEMA) and poly(amic acid) (PAA), respectively. The ultrasound responsiveness of PAA vesicles at metastable state could be regulated by tuning the self-assembly temperature ( T s ), and was optimized when T s is around the glass transition temperature ( T g ) of PAA. However, the PMEMA LCMs did not respond to ultrasound as they are at stable state. On the other hand, poly(2-(2-ethoxyethoxy)ethyl acrylate) (PEEA) could self-assemble into vesicle aggregates or complex micelle aggregates, which were dissociated upon sonication. Overall, the above findings provide us with a fresh insight for designing ultrasound-responsive polymeric nanoparticles.
研究领域:
材料科学
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生物医学工程
·
药学
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DOI
高影响因子
RUSSIAN JOURNAL OF APPLIED CHEMISTRY
·
2023
·Vol. 95
·期 9
·1489-1496
·
IF 0.9
Li Baixin
Abstract The object of this article was to synthesize a special type of functional polymer material with antimicrobial activity. In this paper, polymer antibacterial materials were synthesized in two steps: (1) acrylamide–cefotiam was synthesized via acrylate chloride reaction with cefotiam at 0–5°C for 8 h；(2) The poly(acrylamide–cefotiam) and poly(acrylamide-co-acrylamide–cefotiam) were synthesized via free radical polymerization method in 60°C using water as the solvent and ammonium persulfate as the initiator. The chemical structure and composition of the acrylamide–cefotiam and obtained polymers were investigated by Fourier transform infrared (FTIR) spectrum and Nuclear magnetic resonance (NMR) spectroscopy. The number-average molecular weight ( M n ) of poly(acrylamide–cefotiam) and poly(acrylamide-co-acrylamide–cefotiam) were determined by gel permeation chromatography (GPC). In order to investigate the effect of the obtained polymers bonding of cefotiam on their antimicrobial properties, the contrast and colony counting were used to investigate the antibacterial properties of polymers against ATCC 8739 E. coli . The polymer bonded to cefotiam has 100% antibacterial properties against ATCC 8739 E. coli . Experimental results provide a new method for preparing antimicrobial polymer materials.
研究领域:
材料科学
·
高分子化学
·
药学
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DOI
高影响因子
RSC Advances
·
2014
·Vol. 4
·期 78
·41331-41335
·
IF 3.708
Hui Sun,Lang Fan,Kaidian Zou,Hongshi Zhu,Jianzhong Du
Presented in this article is the proof of principle that silver nanoparticles can be decorated on homopolymer vesicles. The homopolymer vesicles are prepared by self-assembly of poly(2-(2-ethoxyethoxy)ethyl acrylate) (PEEA) in water/tetrahydrofuran (THF) solvent mixture. The –COOH end groups on the surface of the homopolymer vesicle facilitate the growth of ultrafine silver nanoparticles because of the electrostatic interactions between the negatively charged carboxyl group and positively charged Ag+ ions, which were in situ reduced by sodium borohydride (NaBH4). Those silver-decorated PEEA homopolymer vesicles exhibit good antibacterial activity against both Gram-positive and Gram-negative bacteria. This strategy may be extended to prepare more economic antibacterial agents and catalysts.
研究领域:
材料科学
·
生物学
·
纳米技术
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产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2023
·
IF 8.2
Qun Wang,Zhaomei Wang,Jun Song,Kangjie Xu,Wenni Tian,Xu Cai,Jiamei Mo,Yong Cao,Jie Xiao
A nanolipidcarrier (NLC) loaded homogalacturonan enriched pectin (citrus modified pectin, MCP4) hydrogel was designed as a novel colon inflammation site-specific oral delivery system for 6-gingerol (6G) (6G-NLC/MCP4 hydrogel) administration, and its colitis alleviation effect were investigated. 6G-NLC/MCP4 exhibited typical “cage-like” ultrastructure with 6G-NLC embedded in the hydrogel matrix as observed by cryoscanning electron microscope. And due to the homogalacturonan (HG) domain in MCP4 specifically combined with Galectin-3, which is overexpressed in the inflammatory region, the 6G-NLC/MCP4 hydrogel targeted to severe inflammatory region. Meanwhile, the prolonged-release characteristics of 6G-NLC provided sustained release of 6G in severe inflammatory regions. The matrix of hydrogel MCP4 and 6G achieved synergistic alleviation effects for colitis through NF-κB/NLRP3 axis. Specifically, 6G mainly regulated the NF-κB inflammatory pathway and inhibited the activity of NLRP3 protein, while MCP4 regulated the expression of Galectin-3 and peripheral clock gene Rev-Erbα/β to prevent the activation of inflammasome NLRP3.
研究领域:
药学
·
生物医学工程
·
炎症生物学
·
药物递送系统
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产品关联
DOI
PubMed
高影响因子
Nature Communications
·
2022
·Vol. 13
·期 1
·1-9
·
IF 17.694
Sun Hui,Chen Shuai,Li Xiao,Leng Ying,Zhou Xiaoyan,Du Jianzhong
The precise control of the shape, size and microstructure of nanomaterials is of high interest in chemistry and material sciences. However, living lateral growth of cylinders is still very challenging. Herein, we propose a crystallization-driven fusion-induced particle assembly (CD-FIPA) strategy to prepare cylinders with growing diameters by the controlled fusion of spherical micelles self-assembled from an amphiphilic homopolymer. The spherical micelles are heated upon glass transition temperature ( T g ) to break the metastable state to induce the aggregation and fusion of the amorphous micelles to form crystalline cylinders. With the addition of extra spherical micelles, these micelles can attach onto and fuse with the cylinders, showing the living character of the lateral growth of cylinders. Computer simulations and mathematical calculations are preformed to reveal the total energy changes of the nanostructures during the self-assembly and CD-FIPA process. Overall, we demonstrated a CD-FIPA concept for preparing cylinders with growing diameters.
研究领域:
化学
·
材料科学
·
纳米技术
✓ 已验证
DOI
高影响因子
LANGMUIR
·
2015
·
IF 4.457
Hui Wang,Xuefeng Shi,Danfeng Yu,Jian Zhang,Guang Yang,Yingxian Cui,Keji Sun,Jinben Wang,Haike Yan
The current study is aimed at investigating the effect of cationic charge density and hydrophobicity on the antibacterial and hemolytic activities. Two kinds of cationic surfmers, containing single or double hydrophobic tails (octyl chains or benzyl groups), and the corresponding homopolymers were synthesized. The antimicrobial activity of these candidate antibacterials was studied by microbial growth inhibition assays against Escherichia coli, and hemolysis activity was carried out using human red blood cells. It was interestingly found that the homopolymers were much more effective in antibacterial property than their corresponding monomers. Furthermore, the geminized homopolymers had significantly higher antibacterial activity than that of their counterparts but with single amphiphilic side chains in each repeated unit. Geminized homopolymers, with high positive charge density and moderate hydrophobicity (such as benzyl groups), combine both advantages of efficient antibacterial property and prominently high selectivity. To further explain the antibacterial performance of the novel polymer series, the molecular interaction mechanism is proposed according to experimental data which shows that these specimens are likely to kill microbes by disrupting bacterial membranes, leading them unlikely to induce resistance.
研究领域:
聚合物化学
·
微生物学
·
生物医学工程
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产品关联
DOI
PubMed
高影响因子
Nature Communications
·
2023
·Vol. 14
·期 1
·1-19
·
IF 16.6
Song Jianwen,Kang Xiaoying,Wang Lu,Ding Dan,Kong Deling,Li Wen,Qi Ji
The formation of an occlusive thrombus in the blood vessel is the main culprit for numerous life-threatening cardiovascular diseases that represent the leading cause of morbidity and mortality worldwide. Herein, we develop a polymer nanoplatform that integrates long-wavelength second near-infrared (NIR-II) photoacoustic imaging-based thrombosis detection and antithrombotic activity. We design and synthesize a semiconducting homopolymer with strong absorption in the NIR-II region and molecular motion that boosts photothermal conversion and photoacoustic signal. We dope the homopolymer with a thermosensitive nitric oxide donor to formulate a nanoplatform, on which a fibrin-specific ligand is functionalized to ensure selective thrombus targeting. We show that with strong NIR-II light harvesting capability, bright photoacoustic signal and active thrombus accumulation ability, the NIR-II photoacoustic nanoprobes are able to sensitively and selectively delineate thrombi. We find that the nanoplatform also displays rapid and efficient blood clot removal activity with nearly complete blood flow restoration in both carotid thrombosis models and low extremity arterial thrombosis models under NIR-II light trigger by integrating a thrombus-localized photothermal effect and on-demand nitric oxide release. This nanoplatform offers a versatile approach for the diagnosis and treatment of life-threatening diseases caused by various thrombotic disorders.
研究领域:
生物医学工程
·
诊疗学
·
纳米技术
·
心血管疾病
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）