CELLULOSE
·
2018
·Vol. 25
·期 3
·1705-1714
·
IF 3.809
Liu Ting,Ding Enyong,Xue Feng
Polymer grafting is an efficient way to obtain functional cellulose nanocrystals. In this work, we used a “macro-RAFT (macromolecular reversible addition–fragmentation chain transfer) agent-assisted” strategy, which adds extra amount of amphiphilic macro-RAFT agent with low molecular weight to graft poly(N,N-dimethylacrylamide) (PDMA) from cellulose nanocrystals. Successful grafting was evidenced by different characterization methods, and a high weight ratio of grafted PDMA was obtained (77.6%). The grafting process was studied through the weight ratio of grafted PDMA, monomer conversion, and the molecular weight of free and grafted PDMA at different reaction time. As a result, we have suggested that there were three types of grafted polymer chains on cellulose nanocrystals in this reaction system and discussed their evolution during the grafting reaction. Finally, we summarized several key factors for successful grafting in this macro-RAFT agent-assisted strategy.
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
Solar RRL
·
2024
·Vol. 8
·期 14
·2400244
·
IF 6
Mingyue Xiao,Bin Chen,Li Pan,Liya Zheng,Runze Yu,Zhu Fang,Gang Chen
Herein, a new type of CsPbI 3 -based 2D Dion–Jacobson (DJ) perovskites is reported, featuring a general formula of (PDMA)Cs n −1 PbnI 3 n +1 ( n = 1, 2, 3, 4) with 1,4-phenylenedimethanammonium (PDMA) as the organic spacer cation. The crystal structure, optical and electric properties, and surface morphology of the perovskite films are fully surveyed. The solar cell device based on the n = 4 film delivers a champion power conversion efficiency (PCE) of 11.27%, further improved to 12.61% by treating with the PDMA molecules. The PDMA passivation suppresses non-radiative recombination, extends charge-carrier lifetime, and reduces open-circuit voltage loss. A gradient energy level near the film surface facilitates electron extraction, alleviating charge accumulation. The PDMA molecules form a protective layer, inhibiting water infiltration and enhancing stability. The optimized device exhibits excellent shelf stability with no PCE decay after 110 days. In this study, a dual-functional molecule is introduced as a new DJ-type spacer and an effective passivation agent for efficient and stable CsPbI 3 -based 2D perovskite solar cells.
研究领域:
材料科学
·
光伏技术
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
CHINESE JOURNAL OF POLYMER SCIENCE
·
2013
·Vol. 31
·期 4
·691-701
·
IF 1.27
Tan Lin,Xing Jin-xing,Cao Fu-hu,Chen Li-juan,Zhang Chong,Shi Rong-hua,Wang Yan-mei
A series of double-hydrophilic double-grafted PMA- g -PEG/PDMA copolymers, which contained poly(methacrylate) (PMA) as backbone, poly(ethylene glycol) (PEG) and poly( N,N -dimethylacrylamide) (PDMA) as side chains synthesized successfully by using reversible addition-fragmentation chain transfer (RAFT) polymerization and atom transfer radical polymerization (ATRP), were used as physical coatings for the evaluation of protein-resistant properties by capillary electrophoresis (CE). Electroosmotic flow (EOF) measurement results showed that the PMA- g -PEG/PDMA copolymer coated capillaries could suppress electroosmotic mobility in a wide pH range (pH = 2.8–9.8) and EOF mobility decreased with the increase of copolymer molecular mass and PDMA content. At the same time, protein recovery, theoretical plate number of separation and repeatability of migration time demonstrated that antifouling efficiency was improved with the increase of molecular mass and PEG content.
研究领域:
高分子化学
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生物医学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2018
·
IF 6.578
Ming-Yong Zhou,Li-Feng Fang,Chuang-Chao Sun,Chun-Er Lin,Bao-Ku Zhu,Jiang-Hua Chen
Different from the typical interfacial polymerization for nanofiltration membrane fabrication, we proposed a novel method to prepare charged nanofiltration membrane via rapid immersion thermal annealing process with the ultrafiltration membrane, which was prepared from the amphiphilic copolymer , poly(vinyl chloride) -g- poly(2-(dimethylamino)ethyl methacrylate) (PVC -g- PDMA) via non-solvent induced phase separation. The pore structures and chemical properties of the membranes, and annealing conditions including the media where the membrane was annealed, annealing temperature and time, were investigated in detail. It is found that the porous separation layer was collapsed to be a stable, defect-free, and smooth film as the dense separation layer of nanofiltration membrane when it was annealed in n -heptane above its glass transition temperature ( T g ) for only 1 min while the pore size cutoff was tailored from 20 nm to 2 nm. Salt rejections were in the order of MgCl 2 > NaCl > MgSO 4 > Na 2 SO 4 at neutral condition due to Donnan repulsion, indicating a typical positively charged nanofiltration membrane. Overall, this rapid immersion thermal annealing process provides a facile and effective strategy to tailor ultrafiltration membrane toward nanofiltration applications for amphiphilic copolymer based membranes.
研究领域:
材料科学
·
化学工程
·
膜技术
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产品关联
DOI
高影响因子
Polymer Chemistry
·
2018
·Vol. 9
·期 29
·4063-4072
·
IF 4.927
Yan Chen,Yuting Gao,Lucília P. da Silva,Rogério P. Pirraco,Mengdi Ma,Liming Yang,Rui L. Reis,Jie Chen
The aim of this research was to develop thermo- and pH-responsive hydrogels based on H-bonds for the sustained release of the small-molecule model drug Methylene Blue (MB). The thermo- or pH-sensitive triblock copolymer based on PNIPAM or PAA was synthesized by sequential RAFT polymerization and hydrolysis. By tuning the temperature or pH, the copolymer was able to form diverse nanostructures, including core–shell micelles, electronegative or uncharged core–shell structures and 3D networks with the hydrophobic forces of PNIPAM or H-bonds between PAA and PNIPAM. Furthermore, the reversible sol–gel transition of the copolymers was modulated by temperature (∼37 °C), pH (∼5) and concentration (∼7 wt%). The drug release potential was evaluated via in vitro injection of copolymer hydrogels into a simulated human body device. The copolymer hydrogels exhibited a sustained drug release behavior and a low instantaneous drug concentration. The MTT studies revealed that there is no noticeable cytotoxicity of NDB or NDA hydrogels against cells. Thus, the tunable drug release efficiency suggests the possibility of PNIPAM- and PAA-based environment responsive hydrogels being applied as drug carrier systems.
研究领域:
材料科学
·
生物医学工程
·
药剂学
✓ 已验证
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2021
·Vol. 45
·期 13
·5925-5932
·
IF 3.591
Cheng Zhou,Yan Chen,Mingjun Huang,Yi Ling,Liming Yang,Guochen Zhao,Jie Chen
A dual temperature-responsive triblock polymer (poly(N-isopropyl acrylamide)-block-poly(N,N-dimethyl acrylamide)-block-poly(acrylamide-co-acrylonitrile)) (P(AM-co-AN)-b-PDMA-b-PNIPAM) (NDAA) was obtained by sequential reversible addition–fragmentation chain transfer (RAFT) polymerization,with the uncharged UCST temperature-sensitive block P(AM-co-AN) and the classic LCST-type temperature-sensitive block PNIPAM. This well-defined thermo-responsive copolymer with tunable compositions exhibits a dual thermal response behavior in water. Properly designing the length of the block can make the block copolymer undergo a phase transition within the envisaged temperature range. When the concentration is 5 wt%, the UCST of the NDAA polymer is around 20 °C, and the LCST is around 31 °C. All three blocks of these polymers are soluble in water within 20–31 °C. At high temperature, PNIPAM hydrophobically aggregates into a core, and NDAA self-assembles into a core1 (PNIPAM)–shell (PDMA)–corona1 (P(AM-co-AN)) structure. In contrast, at low temperatures, P(AM-co-AN) forms hydrogen bonds and is insoluble in water, and NDAA self-assembles into a core2–shell–corona2 structure. In this way, it is possible to prepare spontaneously reversible micellar aggregates in water. After the concentration reaches the lowest critical concentration, the NDAA polymer can undergo a reversible gel behavior, that is, a phase transition occurs near the UCST and LCST. This change in the polarity of the micelle core opens up the possibility of dissolving different compounds in water just by changing the temperature.
研究领域:
高分子化学
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材料科学
✓ 已验证
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2020
·Vol. 44
·期 34
·14551-14559
·
IF 3.288
Cheng Zhou,Yan Chen,Mingjun Huang,Yi Ling,Liming Yang,Guochen Zhao,Jie Chen
A brand new pH and thermo-responsive amphiphilic ABC triblock copolymer of poly(acrylic acid)-block-poly(N,N-dimethyl acrylamide)-block-poly(acrylamide-co-acrylonitrile) (PAA-b-PDMA-b-P(AM-co-AN)) was synthesized via sequential reversible addition–fragmentation chain transfer (RAFT) polymerization. Due to the pH-responsive blocks of PAA and thermo-responsive blocks of P(AM-co-AN), the properties of the copolymer solution were controlled by varying parameters such as temperature and pH. Specifically, it formed different nanostructures and showed gel behavior under different conditions. In detail, under high temperature alkaline conditions, ADAA was dissolved in an aqueous solution in the form of a molecular chain. Thereafter, when the temperature became lower or pH became acidic, the triblock copolymer self-assembled into different micelle structures, including shell–core, core–shell–core and tighter core–linking–core nanoparticles. In addition, the phase transition temperature of the copolymer was adjusted by pH and concentration. When the copolymer hydrogel was injected into a simulated human body device, it showed sustained drug release behavior and low transient drug concentrations. MTT experiments demonstrated the good biocompatibility of the ADAA hydrogels. This research provides inspiration to develop new polymers which are expected to be promising candidates as part of drug delivery platforms. Compared with traditional responsive hydrogels, its UCST can be easily controlled and is more stable through the feeding ratio, making it more advantageous in human drug delivery applications. In summary, we believe that this UCST and pH-responsive injectable ADAA hydrogel is researchable and applicable in the biomedical field.
研究领域:
材料科学
·
生物医学工程
·
药学
✓ 已验证
DOI
高影响因子
BIOMATERIALS
·
2021
·
IF 12.479
Yanzi Yan,Huiyi Liang,Xingliang Liu,Lixin Liu,Yongming Chen
Abnormal high level of cell free DNA (cfDNA) triggers chronic inflammation to exacerbate psoriasis symptoms. Scavenging cfDNA by topical cationic polymeric nanoparticles has been certified as an effective therapeutic strategy for treating psoriasis. However, cationic cfDNA scavengers have a great potential risk to organs after entering systemic circulation through skin barrier. For better transformation to clinical application, herein a series of poly(2-(dimethylamino)ethyl methacrylate) (PDMA) grafted hairy silica particles (cSPs) with tunable PDMA length and particle size are applied to scavenge cfDNA in dermis. We reveal that the structure of cSPs correlates with the permeation ability across stratum corneum, retention time in dermis, binding affinity to cfDNA, and toxicity tolerance, which in turn affect the therapeutic effect. Especially, the cSPs of 700 nm show more accumulation and longer retention in psoriatic lesions, leading to excellent treatment results. They also outperform the cSPs of 200 nm at a lower administration frequency. Thus, we address the issues of size, cationic content of cSPs to open a potential new avenue to topically treatment of psoriasis by targeting cfDNA in dermis.
研究领域:
药学
·
纳米技术
·
皮肤科
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2020
·
IF 8.758
Yufei Cao,Mingsheng Liu,Ju Cheng,Juanjuan Yin,Congshu Huang,Haiyan Cui,Xiangdong Zhang,Guanghui Zhao
Nitric oxide (NO) gas therapy has aroused intense interest in recent years. l-Arginine (l-Arg) reacts with reactive oxygen species (ROS) in tumor cells to generate NO. This phenomenon represents an effective method for tumor therapy. However, endogenous ROS levels in most types of tumor cells cannot enable an effective reaction. β-Lapachone is generally used to increase H2O2, which can oxidize guanidine derivatives to form nitric oxide in tumor cells. In addition, based on the ferrocene (Fc)-catalyzed Fenton reaction, ·OH is generated from H2O2, and the ONOO– could be generated from an interaction between ·O2– (generated through the Haber–Weiss reaction) and NO. Arg-rich poly(ε-caprolactone) (PCL)-b-PArg, a macromolecular NO donor, was accurately synthesized to avoid premature l-Arg leakage during in vivo transport. In this design, the self-assembled PCL-b-PArg nanoparticles were dressed with the tumor-shreddable masking (PEG-b-PDMA, a negatively charged pH-sensitive hydrophilic diblock polymer), to prepare P-lapa-Fc nanoparticles and hide penetrative capability in the circulation. The experimental results confirmed that this synergistic therapy based on ROS and NO had a significant inhibitory effect on cancer cells, thereby providing new inspiration for NO gas treatment.
研究领域:
癌症治疗
·
纳米医学
·
药物化学
·
生物医学工程
✓ 已验证
DOI
PubMed
高影响因子
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.
研究领域:
聚合物科学
·
材料化学
·
胶体科学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
Xueting Wang,Jing Yang,Qimeng Zhao,Xianchang Xie,Fuling Deng,Ziyi Wang,Kunpeng Jiang,Xiaoming Li,Hu Liu,Zhenhao Shi,Xu Zhu,Lei Chen,Dalun Lv
Macromolecule hydrogels made from natural extracts have received much attention because of their favorable biocompatibility and wound healing properties. However, their clinical applications are limited by their insufficient mechanical strength and low adhesion properties. To overcome these limitations, we developed a novel injectable Aloe vera hydrogel (PDMA-GelMA@AV). By integrating gelatin methacrylate (GelMA) and polydopamine methacrylamide (PDMA), we significantly improved the mechanical and adhesion properties of the hydrogel. The PDMA-GelMA@AV hydrogel degraded in a simulated wound environment, which was synchronized with the sustained release of the bioactive components of A. vera . In vitro and in vivo analyses revealed that this hydrogel has good biocompatibility. In vitro studies also revealed that the sustained release of the active ingredients of A. vera promoted fibroblast proliferation and migration and increased the expression of key proteins and mRNAs required for wound healing. In addition, it modulated LPS-stimulated macrophages and decreased the expression of TNF-α, IL-1β and iNOS while increasing the expression of TGF-β and ARG. In vivo experiments further confirmed the efficacy of hydrogels in wound healing applications. These findings offer a novel perspective on the application of natural macromolecules as hydrogel-based delivery vehicles in wound care.
研究领域:
生物医学工程
·
材料科学
·
伤口愈合
·
药剂学
·
生物材料
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Polymer Chemistry
·
2014
·Vol. 5
·期 21
·6244-6255
·
IF 5.368
Yuanyuan Xu,Youcheng Li,Xueteng Cao,Qijing Chen,Zesheng An
Reversible addition–fragmentation chain transfer (RAFT) dispersion polymerization in cononsolvents of poly(N-isopropylacrylamide) (PNIPAM) was developed as a versatile strategy for the synthesis of thermoresponsive nanogels with controlled composition, functionality and architecture. Cononsolvents composed of mixtures of methanol, ethanol and isopropanol with water were first screened for their suitability as the media for dispersion polymerization of NIPAM, and water–ethanol (75 : 25, v : v) solution was selected due to good RAFT control, efficient formation of nanogels and low toxicity. RAFT dispersion polymerization of NIPAM in the cononsolvent using poly(N,N-dimethylacrylamide) (PDMA) as the macromolecular chain transfer agent (Macro-CTA) showed good control over the molecular weight, polydispersity and pseudo linear polymerization kinetics, as characterized by gel permeation chromatography (GPC) and 1H NMR. The effect of the molecular weight of Macro-CTA, the degree of polymerization of PNIPAM, the molar ratio of [crosslinker] : [Macro-CTA] and the solid content on the formation and size of nanogels was investigated. The thermal profiles of nanogels were characterized by dynamic light scattering (DLS) both in cononsolvents and water. This cononsolvency strategy for dispersion polymerization was shown to be compatible with the incorporation of hydrophilic comonomers of N-(2-hydroxyethyl)acrylamide (HEAM) and diacetone acrylamide (DAAM). The nanogel containing DAAM was demonstrated for postpolymerization modification using ketone–alkoxyamine chemistry. More importantly, dispersion polymerization in cononsolvents allowed various hydrophobic components, e.g. butyl acrylate (BA), fluorescein O-acrylate (FLA), and 1,6-hexanediol diacrylate (HDDA), to be reliably copolymerized with NIPAM, showing well controlled polymerization, composition, nanogel size and colloidal stability. Finally, an amphiphilic block copolymer PDMA-b-PBA was used as a Macro-CTA to produce the PDMA-b-PBA-b-PNIPAM triblock copolymer and triple-layered nanogel, taking advantage of the solubility of PDMA-b-PBA and the insolubility of PNIPAM in the water–ethanol solution at the polymerization temperature.
研究领域:
高分子化学
·
材料科学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）