JOURNAL OF PHYSICAL CHEMISTRY B
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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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ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
·
2025
·
IF 6.1
Lirui Hou,Yuhan Fu,Yue Zhao,Chongshan Dai,Chong Zhao,Lihong Fan,Hongbo Hu,Shutao Yin
Ciprofloxacin (CIP) is a synthetic third-generation quinolone antimicrobial agent with broad-spectrum bactericidal activity and widely used in human and veterinary medicine. Some studies have shown that quinolone antibiotics are endocrine disruptors, but the effect of early-life exposure to CIP on testosterone production remains unclear. Using adolescent male C57BL/6 J mice (n = 6 per group) exposed to CIP (1–75 mg/kg) for 30 days, combined with in vitro models of mouse testicular cells (TM3, TM4, GC-2spd), this study investigated the toxic effects of CIP on testosterone synthesis. Animal studies showed that 1 mg/kg CIP significantly decreased serum testosterone levels and increased LH and FSH levels. With increasing doses of CIP, the sperm count of mice was significantly reduced and accompanied by tissue damage in the testes. Through Western blotting, qPCR, and molecular docking analyses, we identified StAR as the key protein mediating CIP-induced testosterone suppression. CIP was found to affect testosterone synthesis by influencing the expression of testosterone synthesis-related proteins in both in vivo and in vitro. Transcriptomic sequencing of pituitary tissues revealed dose-dependent alterations in genes related to GnRH secretion and cAMP signaling pathways. For the first time, we confirmed that CIP inhibits the transcription of StAR by downregulating NR4A1 expression, ultimately blocking testosterone synthesis. In TM3, TM4, and GC-2spd cells, all three cellular activities were inhibited with increasing concentrations of CIP, which causes S-phase cycle block in TM3 and G2/M-phase cycle block in TM4. The study demonstrates that CIP inhibits testosterone synthesis via the NR4A1/StAR pathway, suggesting CIP is an endocrine disruptor and implying low-dose CIP exposures cause more severe effects that should be of widespread concern.
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EUROPEAN POLYMER JOURNAL
·
2024
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IF 5.8
Weiwei Liu,Tengfei Liu,Xiaofei Wang,Yuan Gao,Pingye Deng,Tao Zou,Zhi Luo,Shuangkun Zhang
Development of high-performance fluorescent materials is crucial for fluorescence imaging technology. Herein, well-defined fluorescent star poly-N-isopropylacrylamide (Flu-PNIPAM) was prepared via reversible addition-fragmentation chain transfer (RAFT) polymerization in a continuous-flow microreactor. A tetrafunctional RAFT agent and the functional monomer fluorescein undecylenoyl (Flu-UE) were synthesized, and then pumped into a microreactor with NIPAM monomer together for RAFT polymerization. The microreactor process parameters for the RAFT polymerization were optimized to obtain well-defined Flu-PNIPAM. The NIPAM and Flu-UE units endow Flu-PNIPAM with temperature and pH responsiveness, respectively. Transmission electron microscopy and dynamic light scattering analyses revealed that Flu-PNIPAM self-assembled into nanoparticles with uniform size in an aqueous solution at 37 °C. Moreover, Flu-PNIPAM exhibited good fluorescence and biocompatibility, rendering it highly promising for cell imaging.
研究领域:
高分子化学
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生物医学工程
·
材料科学
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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
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化学工程
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POLYMER
·
2021
·
IF 4.43
Liang Xiang,Zihao Zhong,Minjing Shang,Yuanhai Su
In cascade microreactor systems, a series of star polymers , in which poly(di(ethylene glycol) ethyl ether acrylate-co-oligoethylene glycol acrylate) served as the thermoresponsive arm and poly(N, N-dimethylaminoethyl acrylate) as the pH-responsive arm, were successfully prepared via the RAFT arm-first method. Results showed that the compositions of star products were close to the designed feed ratios, and the lower critical solution temperature (LCST) was affected by the arm composition and the external pH. Due to the more compact structure, star polymers had a smarter temperature response than the linear chains. Moreover, the Au nanoparticles formed by coordination reduction of star products could be efficiently applied in the 4-nitrophenol catalytic reduction process, and the reaction rate was affected by the arm composition, pH and temperature. This research demonstrated that polymer products with particular functions could be customized by tailoring the polymer structures in a facile microflow polymerization mode.
研究领域:
高分子化学
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材料科学
·
催化化学
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INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2018
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IF 3.141
Xiangfei Zheng,Changwei Ji,Jingcheng Liu,Ren Liu,Qidao Mu,Xiaoya Liu
Xanthate-mediated reversible addition–fragmentation chain transfer (RAFT) methodologies have been applicable to preparation of branched or star polymers. In this article, novel star copolymers have been synthesized through xanthate-mediated RAFT polymerization with p-acetoxystyrene and tert-butyl acrylate. Fourier transfer infrared, nuclear magnetic resonance spectra, and gas chromatography analyses indicated that the polymerization was successful between both of the monomers and the star RAFT agent. The intrinsic viscosity and Zimm branching factor (g′) were used to confirm the copolymers’ architecture. The ultraviolet absorbance of the copolymer solutions indicated that the copolymer was suitable for use as a krypton fluoride (KrF) laser photoresist. Moreover, the photolithography performance of the positive-tone chemically amplified photoresist was evaluated. The results indicated that the photosensitive based on the star copolymer was higher than the linear one, and the pattern resolution was around 200 nm at a low exposure energy.
研究领域:
材料科学
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高分子化学
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SYNTHETIC METALS
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2020
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IF 3.286
Song Liu,Zhen-jie Huang,Feng Li,Wei-jing Zhang,Chun-rong Zhu,Cheng-bin Gong,Jun-fei Long,Qian Tang
In this study, a series of novel star-shaped monosubstituted 2,6-diphenyl-4,4′-bipyridinium salts with various alkyl, alkenyl, and aryl groups were designed and synthesized, and their electrochemical, electro-optical, and electrochromic properties were investigated. The electrochromic properties such as different colored states (sky blue versus purple), reasonable contrast, coloration efficiency, and, in particular, the switching stabilities of electrochromic devices based on star-shaped monosubstituted 2,6-diphenyl-4,4′-bipyridinium salts were better than those of devices based on linear monosubstituted pyridinium salts. All the compounds with alkyl, alkenyl, and aryl groups showed good switching stability and the change in the optical contrast after 1000 cycles was small (<5%). However, N-substituents significantly affected the switching stability of electrochromic devices based on linear monosubstituted 4,4′-bipyridine derivatives.
研究领域:
材料科学
·
电化学
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Polymer Chemistry
·
2018
·Vol. 10
·期 2
·228-234
·
IF 4.927
Chao Chen,Xiaofeng Guo,Jinhong Du,Bonnie Choi,Houliang Tang,Anchao Feng,San H. Thang
Miktoarm star (MAS) polymers are polymers with a number of distinct arms connected to a central core. Owing to their exclusive structure, MAS polymers have been extensively studied in recent years. To exploit their biomedical applications the combination of nucleic acids, peptides and saccharides are desired. In this study, RAFT polymerization of three monomers with markedly different properties, N,N-dimethylaminoethyl methacrylate (DMAEMA, cationic), n-butyl methacrylate (BMA, hydrophobic) and oligo(ethylene glycol) methyl ether methacrylate (OEGMA, hydrophilic) was conducted using an RGD peptide based RAFT agent as a chain transfer agent (RGD-CTA). With a disulphide dimethacrylate (DSDMA) redox-cleavable cross-linker, the above linear polymers were combined via an “arm-first” technique to access MAS polymers containing peptide arms. These MAS polymers showed excellent biocompatibility, cell staining performance and rapid redox responsiveness. The novel MAS polymers have potential as a prospective platform for intracellular drug/gene delivery for cancer therapy.
研究领域:
高分子化学
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材料科学
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生物医学工程
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药学
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Materials
·
2019
·Vol. 12
·期 10
·1610
·
IF 2.972
Wenzhao Jiang,Jianwei Guo,Weiqiu Wen,Yong-Guang Jia,Sa Liu
Polymeric nano-carriers are considered as promising tools in biomedical applications due to multiple attractive characteristics including their low toxicity, high loading capacity, controlled drug release capabilities, and highly tunable chemical properties. Here, a series of pH-sensitive star-shaped copolymers, Ad-P[(EMA-co-MAA)-b-PPEGMA]4, was prepared via electron transfer atom radical polymerization (ARGETE ATRP) and selective hydrolysis. These star-shaped copolymers can be self-assembled into micelles (Dh= 150–160 nm) and their critical micelle concentrations (CMC) were estimated to be 3.9–5.0 mg/L. The pH-sensitiveness of the micelles was evidenced by transmission electron microscopy (TEM) and dynamic light scattering (DLS). The maximal paclitaxel (PTX) loading efficiency (DLC) and entrapment efficiency (EE) were 18.9% and 36%, respectively. In vitro release studies revealed that about 19% of the PTX released at an acidic condition of pH 1.2 over 70 h, whereas more than 70% was released within the same time interval at pH 6.8. In vitro cytotoxicity suggested that the low cytotoxicity of the blank micelles, while the PTX-loaded micelles providing the cytotoxicity close to that of free PTX. These results indicated that this novel pH-sensitive nano-carriers have great potential applications for oral drug-controlled release.Keywords:nano-carrier;pH-sensitive copolymer;drug release;adamantane
研究领域:
药剂学
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高分子化学
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生物医学工程
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Polymer Chemistry
·
2013
·Vol. 4
·期 6
·1921-1931
·
IF 5.231
Wei Zhou,Weijun Yu,Zesheng An
Core cross-linked star (CCS) polymers of poly(N,N-dimethylacrylamide) (PDMA) were prepared and explored as macromolecular chain transfer agents (Macro-CTAs) in the emulsion polymerization of styrene. The mass ratio of styrene : CCS and the solid content were systematically varied to elucidate their effect on the size and morphology of the particles. Control experiments using linear PDMA as a Macro-CTA were also performed in order to understand the mechanistic difference in CCS-mediated emulsion polymerization. While a two-phase process was typical of emulsion polymerization using linear Macro-CTAs, the CCS polymers functioned as “seeds” for the emulsion polymerization of styrene and exhibited a much higher polymerization rate. Significant clustering of spherical particles was observed when the mass ratio of styrene : CCS was increased while maintaining the solid content. On the other hand, linear and branched fibers were observed when the solid content was increased while maintaining the mass ratio of styrene : CCS. This morphology transformation is unique to CCS-mediated emulsion polymerization, and a protrusion mechanism caused by the cross-links in the core of the CCS was proposed to account for the aggregation of spherical particles into clusters or fibers.
研究领域:
材料科学
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高分子化学
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CHINESE JOURNAL OF POLYMER SCIENCE
·
2014
·Vol. 33
·期 2
·245-255
·
IF 1.42
Zhang Di,Yin Jun,He Fei,Ge Ni-lin,Wu Zong-quan,Ding Yun-sheng
We report on the preparation of a well-defined star-shaped tricationic ionic liquid possessing three arms of poly(ethylene glycol) functionalized imidazolium rings. Remarkable solubility was found in most of the organic solvents we used. Thermogravimetric analysis (TGA) exhibited excellent thermal stability and two distinct decomposition temperatures were attributed to two kinds of chemical degradation. Differential scanning calorimetry (DSC) was further employed to investigate the thermal phase transitions, that three different signals ( T
g , T
c , and T
m ) were shown upon the second heating process. Moreover, CH 2 Cl 2 solution of the ionic liquid expressed an excitation-wavelength dependent fluorescence response, leading to the facile modulation of photoluminescence behavior. This work represents an example of utilizing molecular design to construct novel ionic liquids and endow further potential to be used in the engineering materials.
研究领域:
材料科学
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化学工程
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COLLOIDS AND SURFACES B-BIOINTERFACES
·
2017
·
IF 3.887
Ruitao Cha,Juanjuan Li,Yang Liu,Yifan Zhang,Qian Xie,Mingming Zhang
Fe 3 O 4 nanoparticles with ultrasmall sizes show good T 1 or T 1 + T 2 contrast abilities, and have attracted considerable interest in the field of magnetic resonance imaging (MRI) contrast agents. For effective biomedical applications, the colloidal stability and biocompatibility of the Fe 3 O 4 nanoparticles need to be improved without reducing MRI relaxivity. In this paper, star polymers were used as coating materials to modify Fe 3 O 4 nanoparticles in view of their dense molecular architecture with moderate flexibility. The star polymer was composed of a β-cyclodextrin (β-CD) core and poly(2-(dimethylamino) ethyl methacrylate) (PDMAEMA) arms. Meanwhile, reduced glutathione (GSH), as a model drug, was also associated with the star polymer. Thus, a new platform for simultaneous diagnosis and treatment was achieved. Compared to the Fe 3 O 4 nanoparticles coated with linear polymers, the Fe 3 O 4 nanoparticles coated with star polymers (Fe 3 O 4 @GCP) possessed higher GSH association capacity and better stability in serum-containing solution. GSH could be released from Fe 3 O 4 @GCP nanoparticles in response to pH value of the solution. Since the sulfhydryl group on GSH is able to combine free radicals, Fe 3 O 4 @GCP nanoparticles exhibited less cytotoxicity compared to the Fe 3 O 4 nanoparticles without including GSH. Furthermore, the nanoparticles could also serve as good T 1 MRI contrast agent, and the MRI relaxivity of Fe 3 O 4 @GCP nanoparticles did not decrease after coated with the star polymer. These results indicate that the precisely designed Fe 3 O 4 @GCP nanoparticles could be used as a versatile promising theranostic nano-platform.
研究领域:
纳米技术
·
材料科学
·
生物医学工程
·
磁共振成像
·
药物递送系统
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