JOURNAL OF MATERIALS SCIENCE
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2022
·Vol. 57
·期 16
·7791-7803
·
IF 4.682
Ma Yanli,Wu Hailiang,Shen Yanqin
We herein report novel POSS-containing linear and star multi-arm organic–inorganic hybrid block copolymers (BCPs) L/S -(PGMA- b -PMAPOSS) 1,2,4,6 synthesized by the core-first ATRP method. Following, crosslinking of the BCPs conducted by the reaction of the glycidyl groups in the PGMA block in the presence of trimethylamine to form the 3-dimensional network and the crosslinking cured BCPs were used for the subsequent properties characterization. Based on the chemical structures being confirmed, the self-assembly behaviors in the aqueous solution and film surface property were investigated in detail. The results showed that linear L -(PGMA- b -PMAPOSS) 2 formed typical core–shell spherical micelles where the hydrophobic PMAPOSS blocks as the core and PGMA blocks as the shell. With the increasing number of arms of the hybrid BCPs, the aggregates were tuned from spherical micelles to dendritic cylinders. Besides, with the increases in the solubility of the solvent, the aggregates tended to form the spherical morphology. The hydrophobic property of the hybrid BCPs film improved gradually from linear monobrachial BCPs to star six-arm BCPs. The thermostability of the hybrid BCPs showed similar results owing to the similar MAPOSS proportion. For the adhesive performance to the glass substrate, S -(PGMA- b -PMAPOSS) 6 possessed the best adhesive strength due to the highest density of branches. Graphical abstract
The novel dual-functional linear and star POSS-containing organic-inorganic hybrid block copolymers (BCPs) L/S -(PGMA- b -PMAPOSS) 1,2,4,6 were successfully synthesized by the core-first ATRP method, then crosslinking the BCPs in the presence of trimethylamine to form the 3-dimensional network. And the self-assembly behavior in aqueous solution was studied in detail, as shown in the graphic image. In addition, the surface property, thermostability and adhesive performance were analyzed.
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高影响因子
Nano Research
·
2020
·Vol. 13
·期 1
·160-172
·
IF 8.183
Zhang Amin,Zhang Qian,Alfranca Gabriel,Pan Shaojun,Huang Zhicheng,Cheng Jin,Ma Qiang,Song Jie,Pan Yunxiang,Ni Jian,Ma Lijun,Cui Daxiang
Distinctively different metabolism between tumor cells and normal cells endows tumor tissues unique microenvironment. In this regard, we have successfully prepared a sequential catalytic platform based on Au/Pt star for tumor theragnostic. The multifunctional probes consisted of a gold/platinum star-shaped core (Au/Pt star) conjugated with a GSH-sensitive disulfide bond (S–S), a targeting ligand (rHSA-FA), a near-infrared fluorophore (IR780) and glucose oxidase (GO x ). When systemically administered in a xenografted murine model, the probes specifically targeted the tumor sites. As the disulfide linker was cleaved by intracellular GSH, the IR780 molecules could be released for photo-thermal therapy & photodynamic therapy (PTT&PDT) and imaging. Subsequently, the Pt nanolayer of the Au/Pt star and the GO x formed a sequential catalytic system: GO x effectively catalyzed intracellular glucose by consuming oxygen to generate H 2 O 2 and enhance the local acidity, and the Pt layer exhibited peroxidase-like property to catalyze H 2 O 2 producing toxic ·OH for tumor oxidative damage. Here we demonstrated that our probes simultaneously possessed a GSH-sensitive release, real-time imaging ability, and synergetic cancer starving-like therapy/enzyme oxidative therapy/PTT/PDT features, which provides a potential strategy for effective tumor theragnostic.
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高影响因子
JOURNAL OF LUMINESCENCE
·
2023
·
IF 3.6
Zhinan Jiang,Yang Liu,Lina Ding,Yonggang Yang,Tiantian Guan,Chaochao Qin,Yufang Liu
Star-shaped room-temperature phosphorescent (RTP) molecules have attracted much attention due to high luminescence efficiency by inhibiting nonradiative transition of triplet excitons . In this work, the photophysical processes of 1,3,5-tri(9h-carbazol-9-phenyl)benzene (TCzP) and tri(4-carbazol-9-phenyl)amine (TCzTa), with benzene and triphenylamine (TPA) as central cores respectively and carbazole (Cz) as peripheral groups, are investigated. The excited state absorption (ESA) signal (625 nm) of TCzP reaches maximum intensity within 8.8 ps in the femtosecond (fs) transient absorption (TA) spectroscopy and then decays significantly with the enhancing of triplet-triplet absorption (TTA) signal (425 nm). These evolution processes of spectral signal and the appearance of isosbestic point at 450 nm together confirm the intersystem crossing (ISC) process within 5.1 ns. The TTA signal gradually disappears in the nanosecond (ns) TA spectroscopy with a phosphorescence lifetime (τ ph ) of 2 μs. Compared to TCzP, TCzTa exhibits similar spectral evolution behavior with faster ISC of 2.1 ns and lower τ ph of 0.95 μs. The theoretical simulation shows that the nitrogen atoms in the TPA core of TCzTa leads to a significantly increased spin-orbit coupling constant of S 1 →T n (0.86 cm −1 ) and T 1 →S 0 (0.08 cm −1 ) than that of TCzP (0.25 cm −1 and 0.05 cm −1 ), resulting in the shorter experimental ISC rate constants (2.1 ns) and τ ph (0.95 μs). This work provides reasonable insights for understanding the real-time spectral signal evolution of star-shaped carbazole-based RTP molecules.
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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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COLLOID AND POLYMER SCIENCE
·
2012
·Vol. 291
·期 4
·789-803
·
IF 2.331
Zhang Xiaojing,Wang Chaojun,Fang Shaoming,Sun Jiashu,Li Chong,Hu Yuelei
In this paper, a series of hybrid star PLLA (sPLLA) with different arm lengths was synthesized via the hydrosilylation between octakis(dimethylsiloxy) silsesquioxane (Q 8 M 8 ) and functionalized PLLA macromolecules with vinyl end groups (mPLLA). mPLLA was synthesized by ring-opening polymerization of l -lactide using 2-hydroxyethylmethacryl as an initiator in the presence of stannous 2-ethylhexanoate as a catalyst. The obtained sPLLA has low polydispersity with polydispersity index values from 1.29 to 1.30. The arm numbers of sPLLA vary from 5 to 7 and decrease with the increase in the length of the mPLLA arm due to the steric hindrance, which are estimated by 1 H NMR analysis. The branched structure of sPLLA is also evidenced by the lower intrinsic viscosity when compared with the linear mPLLA with similar molecular weight. Both the glass transition temperatures ( T
g ’s) and melting temperatures ( T
m ’s) of sPLLAs are higher than those of the mPLLA arms. The incorporation of polyhedral oligomeric silsesquioxane (POSS) does not change the crystalline structure of PLLA, while the crystallinity of sPLLA is enhanced as the result that the POSS core acts as a heterogeneous nucleating agent in the matrix to promote the crystallization ability of PLLA. High-resolution transmission electron microscopy observation suggests that POSS disperses in the crystalline PLLA matrix as 5–20 nm aggregates. Microspheres of sPLLA with mean diameter 1 to 2 μm were prepared via emulsion solvent evaporation method. The sPLLA microspheres have higher loading capacity and encapsulation efficiency and lower drug release rate than mPLLA microspheres.
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高影响因子
COLLOID AND POLYMER SCIENCE
·
2017
·Vol. 295
·期 9
·1609-1619
·
IF 1.723
Ding Amin,Zhou Yifeng,Chen Pengpeng,Nie Wangyan
Amphiphilic star-shaped copolymers based on star-shaped poly(L-lactide) (s-PLLA) and poly(ethylene glycol) (PEG) (s-PLLA-PEG) were synthesized with variable molecular weights (M w ) of PEG, and the relationship between the PEG block molecular weight of s-PLLA-PEG copolymers and their micelle properties were investigated. The structure and M w of s-PLLA-PEG were characterized with 1 H NMR, GPC, DSC, and XRD. The ibuprofen (IBU)-loaded s-PLLA-PEG micelles were prepared by dialysis method. The effects of PEG block molecular weight on the morphology, particle size, zeta potential, drug loading content (LC), drug encapsulation efficiency (EE), and in vitro drug release behavior of prepared micelles were investigated. Results indicated that the average diameters, LC, and EE of IBU-loaded s-PLLA-PEG micelles increased with increasing the M w of PEG in s-PLLA-PEG copolymers. The in vitro study showed that the IBU accumulative release can be depressed by increasing the M w of the s-PLLA-PEG, and the release profiles of IBU from s-PLLA-PEG followed the Baker-Lonsdale model equation. The results suggest that structural tailoring of PEG length from s-PLLA-PEG copolymers could provide a new strategy for designing drug carriers of high efficiency.
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JOURNAL OF APPLIED POLYMER SCIENCE
·
2016
·Vol. 134
·期 2
·
IF 1.866
Weitao Ye,Wei Wei,Xiaoma Fei,Rongjie Lu,Na Liu,Jing Luo,Ye Zhu,Xiaoya Liu
A six-arm star-shaped poly( ε -caprolactone) (s-PCL) based on cyclophosphazene core was obtained by presynthesis of a hydroxy-teminated cyclophosphazene derivative and subsequent initiation of the ring-opening polymerization of ε -caprolactone, and its use in different proportions as toughening modifier of diglycidylether of bisphenol A/anhydride thermosets was studied. The star-shaped polymer was characterized to have approximately 30 caprolactone units per arm. Differential scanning calorimetry revealed a nonsignificant influence on the curing process of the epoxy-anhydride formulation by the addition of s-PCL. The s-PCL-modified epoxy thermosets exhibited a great improvement in both toughness and strength compared with the neat resin, as the result of a joint effort by the internal rigid core and the external ductile polyester chains of s-PCL. When the addition of the modifier was 3 wt %, an optimal mechanical and thermomechanical performance was achieved. The impact resistance and tensile strength of the cured epoxy resin were enhanced by 150% and 30%, respectively. The glass transition temperature was also increased slightly. Moreover, the addition of the star-shaped modifier had little harmful effect on the thermal stability of the material. Thus s-PCL was proved to be a superior toughening agent without sacrificing thermal and mechanical properties of the thermosets. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44384.
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Polymer Chemistry
·
2013
·Vol. 4
·期 6
·1950-1959
·
IF 5.231
Xiaofang Shi,Miao Miao,Zesheng An
Homoarm and heteroarm core cross-linked star (CCS) polymers based on poly(N,N-dimethylacrylamide) (PDMA) as the high-polarity arm and poly(2-methoxyethylacrylate) (PMEA) as the low-polarity arm were efficiently prepared via reversible addition-fragmentation chain transfer (RAFT) polymerization in a dispersion polymerization system. PDMA and PMEA arm polymers exhibited similar conversion rates, such that their composition in the heteroarm CCS polymers was easily controlled by the feed ratio in the synthesis. The ability to control the arm composition allowed facile tuning of the polarity of the CCS polymers. Heteroarm CCS polymers self-assembled in water to form aggregates and their size was related to the composition and polarity of the CCS polymers. The composition and polarity of the CCS polymers significantly affected the emulsifying behaviour of the CCS polymers as emulsifiers. Oil-in-water (o/w) emulsions were favoured for CCS polymers with relatively high polarity and lowering the polarity of CCS polymers to a certain degree enhanced the stability of the emulsions. Multiple emulsions, both o/w and water-in-oil (w/o), were gradually produced when the polarity of CCS polymers was gradually lowered and the oil fraction in the emulsion samples was gradually increased, and at the same time the emulsions also became increasingly less stable.
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Polymer Chemistry
·
2015
·Vol. 6
·期 39
·7045-7052
·
IF 5.52
Lu Yin,Yin Zhao,Shunqin Jiang,Laibing Wang,Zhengbiao Zhang,Jian Zhu,Wei Zhang,Xiulin Zhu
A series of star-shaped azobenzene (Azo)-containing side chain polymers with 3, 4 and 6 arms were synthesized by the atom transfer radical polymerization technique initiated by multifunctional initiators. The intense bisignated circular dichroism (CD) signals in the UV–vis region were observed when these star polymers aggregated in a dichloroethane/limonene mixed solvent, indicating the successful chirality transfer from limonene molecules to these star Azo polymers. The chirality originates from the preferential supramolecular chirality of well-organized optically inactive side-chain Azo units. The supramolecular chirality is closely related to the volume fraction of cosolvents, the enantiopurity (ee) of limonene, molecular weight and arm numbers of star Azo polymers. Interestingly, the maximum values of CD and gCD of the polymer aggregates increase with molecular weight in the case of 3-armed Azo polymers, and increase simultaneously with arm numbers of the polymers having similar repeating units under each optimized experimental condition. Surprisingly, the first chiral amplification behaviours were observed in the 4- and 6-armed Azo polymers, but absent in linear and 3-armed counterparts. The supramolecular chirality can be destroyed by trans–cis photoisomerization and recovered by thermal cis–trans isomerization of Azo units. The current research will provide further insight into the mechanism study and production of effective chiroptical materials in chiral solvation induced supramolecular chirality of the achiral polymers.
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Polymer Chemistry
·
2014
·Vol. 5
·期 14
·4277-4284
·
IF 5.368
Xueteng Cao,Chunlei Zhang,Songbai Wu,Zesheng An
We have developed a highly efficient, one-step approach for the synthesis of core cross-linked star (CCS) polymers using commercial macromonomers (polyethylene glycol methyl ether methacrylates) as the arms via RAFT-mediated emulsion polymerization in aqueous media. This approach employs a small molecular chain transfer agent (CTA), commercial macromonomer, hydrophobic cross-linker, and optional hydrophobic spacing monomer as the polymerization recipe to synthesize CCS polymers via direct one-step polymerization in aqueous buffer solution. Various polymerization parameters, including buffer concentration and molar ratio of macromonomer/cross-linker/spacing monomer relative to CTA, were investigated. CCS polymers of high yield and low dispersity were obtained within 4 h under a wide range of conditions. Analysis of polymerization kinetics and macromolecular parameters of the generated polymeric species during the polymerization process led to insights into the mechanistic aspects of the CCS formation process, which was proposed to involve three stages, i.e., polymer chain growth, cross-linking to form CCS, and CCS growth. Finally, synthesis of CCS polymers using macromonomers of different molecular weights pointed to the necessity for optimization of the polymerization conditions for each macromonomer, possibly due to different polymerization rates and steric hindrance.
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AICHE JOURNAL
·
2014
·Vol. 61
·期 1
·35-45
·
IF 2.581
Feng Xu,Jing-Wen Xu,Bi-Xia Zhang,Luo Yan-Ling
Novel tri-armed star polystyrene-block-poly(N-isopropylacrylamide) block copolymers with trimesic acid as central molecules were synthesized by successive two-step atom transfer radical polymerization, and confirmed by Fourier-transform infrared spectra, 1 H nuclear magnetic resonance, and laser light scattering gel chromatography system. The copolymers could self-assemble into spherical core-shell micelles in aqueous media independent on drug loading. Physicochemical properties of the blank and drug-loaded micelles were examined by surface tension, fluorescence spectroscopy, UV-vis, transmission electron microscope, and dynamic light scattering measurements. The copolymer micelles exhibited thermo-triggered phase transition, with low critical solution temperature of 33.7 and 34.6°C, varying with copolymer compositions. The critical aggregate concentrations were 11.62 and 47.61 mg L −1 , and hydrodynamic diameters from 200 to 220 nm. Water-insoluble 10-hydroxycamptothecine was encapsulated into the micelle aggregates to investigate the change in the resulting physicochemical parameters, thermo-triggered in vitro drug release, and the applicability as drug targeting release carriers. MTT assays were carried out to uncover cytotoxicity of the newly developed micelle-based drug formulations. © 2014 American Institute of Chemical Engineers AIChE J , 61: 35–45, 2015
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高影响因子
POLYMER
·
2024
·
IF 4.1
Jinqi Chen,Cong Luo,Yanhua Niu,Guangxian Li
Gel polymer electrolyte (GPE) is one of the promising candidates to overcome the defects of liquid and solid electrolyte for lithium metal batteries (LMBs). The obstacle for the practical application of GPEs lies in achieving a balance between ion transport, mechanical properties and interface stability. In this work, a star shaped polymer matrix polyhedral oligomeric silsesquioxane-polymethyl methacrylate (POSS-PMMA) is successfully synthesized with POSS as the core via atom transfer radical polymerization (ATRP) method. 1-ethyl-3-methylimidazole bis(trifluoromethanesulfon)imide ([EMIM][TFSI]) and bistrifluoromethanesulfonimide lithium salt (LiTFSI) are blended with the matrix to increase ionic conductivity. Attributed to the star structure and the lithium ion migration channel provided by POSS, the synthesized GPE possesses excellent balanced mechanical and electrochemical properties. To further stabilize the Li/GPE interface, a polymer and plastic crystalline electrolyte (PPCE) is coated as interface modification layer on both sides of GPE. Benefitting from the design, the synthesized GPE reaches a highly stable Li striping/plating cycling for 1000 h at 0.1 mA cm −2 with ionic conductivity of 3.5 × 10 −4 S cm −1 , Li + transference number of 0.35, and electrochemical stability window of 4.9 V. Furthermore, the Li||POSS-PMMA-PPCE||LiFePO 4 (LFP) full cell shows a high capacity retention of 99.5 % after 100 cycles at 0.2 C under room temperature (RT), and the high voltage Li||POSS-PMMA-PPCE||LiNi 1-x-y MnxCo y O 2 (NCM811) cell shows a high capacity retention of 88.3 % after 50 cycles at 0.1 C under RT. This work opens up a new frontier to stabilize the Li/GPE interface and enables safe operation of room temperature lithium metal batteries.
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危险品化学品经营许可证（带存储）