CHINESE JOURNAL OF CHEMISTRY
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2023
·Vol. 41
·期 18
·2305-2310
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IF 5.4
Rongye Li,Yue Zhao,Min Lin,Jing Sun
Comprehensive Summary Great efforts have been lately devoted to fabricating well-defined nanostructures using crystallization-driven self-assembly (CDSA) strategy. The influence of self-assembly on crystallization is also of great interest. Here, a series of amphiphilic diblock copolypeptoids poly( N -allylglycine)- b -poly( N -octylglycine) modified with cysteamine hydrochloride ((PNAG- g -NH 2 )- b -PNOG) were synthesized by ring-opening polymerization (ROP) and post-polymerization functionalization. The diblock copolypeptoid is comprised of one hydrophobic crystalline PNOG block and one hydrophilic amorphous block, which can aggregate into nanostructured assemblies with soluble PNAG- g -NH 2 as the corona layer and PNOG as the inner core in aqueous solution. With a systematic study by differential scanning calorimetry (DSC) and wide-angle X-ray scattering (WAXS), we demonstrated that the self-assembly of the block copolymers strengthens the crystallization of the PNOG block.
研究领域:
材料科学
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高分子化学
·
生物材料
✓ 已验证
产品关联
DOI
高影响因子
BIOMACROMOLECULES
·
2018
·
IF 5.738
Chao Xing,Zhekun Shi,Jiliang Tian,Jing Sun,Zhibo Li
Stimuli-responsive polymers have received increasing interest for a variety of applications. Here, we report a series of unique charge-determined thermoresponsive polypeptoids synthesized by a combination of ring-opening polymerization and click chemistry. The LCST-type and UCST-type behavior is mainly dominated by the charge state on the side chain. Further, the phase transition temperature highly depends on the degree of polymerization, the side-chain architecture, the pH value, and so on. The obtained polypeptoid solutions exhibit good stability against temperature and salt concentration. To our knowledge, this report presents the first charge-determined LCST/UCST-type polymer from identical homopolymer backbone that displays a wide range of tunable cloudy points in aqueous media. We propose the hydrogen-bonding interaction plays a critical part on the solution behavior. These features make polypeptoids ideal candidates for highly designable stimuli-responsive polymeric materials.
研究领域:
高分子化学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF POLYMER ENGINEERING
·
2011
·Vol. 31
·期 1
·37-44
·
IF 0.493
Liehui Zhang,Ming Duan,Shenwen Fang,Peng Zhang,Jian Zhang,Fuxiao Wang
Star copolymers of acrylamide and N , N -dimethyl- N -vinylnonadecan-1-aminium chloride (C 18 DMAAC) were synthesized by photopolymerization in water. Solution behaviors of these star hydrophobically modified acrylamide copolymers (SHMPAMs) with different C 18 DMAAC contents and the linear hydrophobically modified acrylamide copolymers (LHMPAMs) were characterized. The increase in C 18 DMAAC content resulted in decreased intrinsic viscosity and increased the Huggins constant for SHMPAMs. Similar results were observed for LHMPAMs. With similar intrinsic viscosity and C 18 DMAAC content, the Huggins constant of SHMPAMs was much higher than that of LHMPAMs, which could be due to the fact that SHMPAMs had much stronger intramolecular interaction in dilute polymer solutions. In semi-dilute solutions, the apparent viscosity of SHMPAMs was increased with increasing C 18 DMAAC content, which was similar to that of LHMPAMs. However, SHMPAMs exhibited higher apparent viscosity than LHMPAMs because it had more arms and thus had more chances to form three-dimensional networks in semi-dilute solutions. In the flow-induced scission experiment, SHMPAMs exhibited superior shear stability in comparison with LHMPAMs. When the strain rate was ≈40,000 s-1, the reduction ratios of the apparent viscosities of the four SHMPAMs after the scission were approximately 80%. By contrast, when the strain rate was ≈20,000 s-1, the reduction ratio of the apparent viscosity of LHMPAM-0.40 had already reached around 80%.
研究领域:
高分子化学
·
物理化学
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产品关联
DOI
高影响因子
CRYSTENGCOMM
·
2016
·Vol. 18
·期 47
·9033-9041
·
IF 3.849
Xueyi Guo,Weijia Wang,Ying Yang,Qinghua Tian
The large scale synthesis of magnetite nanocrystals (MNCs) is a sine qua non for supplying the rapidly increasing demand for MNCs in biomedical applications (e.g. magnetic resonance imaging (MRI), magnetic hyperthermia and targeted drug delivery), but it is still difficult to achieve their industrial production due to the operation complexity, strict synthetic conditions and the narrow error tolerance range of existing approaches. Here, we report a facile synthetic procedure using a solvothermal route with an iron acetylacetonate (Fe(acac)3), oleic acid (OA) and oleylamine (OAm) reaction system on a large scale, which is designed under the guidance of the solution behavior regulated formation mechanism of MNCs. Two intermediates, Fe(acac)x(OA)y and N-(cis-9-octadecenyl)-oleamide (OOA), are found to play key roles in adjusting the surface protection status of MNCs and the reducibility of the reaction system. With diverse combinations of surface protection status and reducibility, the final size of MNCs changes from 6.8 nm to 37.4 nm, and the morphology of the MNCs transforms from triangular prismatic to spherical (or quasi spherical), which indicates that the formation of MNCs with distinct sizes and morphologies is attributed to experiencing different pathways from nucleation to growth. Moreover, the reaction system is insensitive to the reaction temperature (220–240 °C) and time (2–6 hours), exhibiting a preferable operation error tolerance range for industrial application. Accordingly, a large scale synthesis is applied for synthesizing high quality MNCs, and 6 grams of spherical and monodispersed MNCs with a diameter of 11.2 ± 0.8 nm are obtained in a single reaction.
研究领域:
材料科学
·
生物医学工程
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产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2015
·Vol. 132
·期 29
·
IF 1.768
Lei Wang,Wen Huang,Shijie Wang,Yuezhi Cui,Pengfei Yang,Xiaodeng Yang,Jonathan V. M. Weaver
pH-Responsive amphiphilic branched copolymers were prepared from poly(ethylene glycol) methyl ether methacrylate (PEGMA), 2-(diethylamino)ethyl methacrylate (DEAEMA), 2-( tert -butylamino)ethyl methacrylate ( t BAEMA), and ethylene glycol dimethacrylate (EGDMA) utilizing a thiol-modified free radical polymerization. The molecular structures of copolymers were confirmed by proton nuclear magnetic resonance spectroscopy ( 1 H NMR) and triple-detection gel permeation chromatography (tri-GPC). The aqueous solution behaviors of the obtained copolymers were investigated by dynamic light scattering (DLS). The DLS data showed that about 16 nm polymer particles comprising of hydrophobic poly( tert -butylamino)ethyl methacrylate (P t BAEMA) and poly(diethylaminoethyl methacrylate (PDEAEMA) core, hydrophilic PEGMA corona were formed above pH 8. With the decrease of pH from 8 to 6, a dramatic increase in the hydrodynamic radius of polymer particles from 16 nm to 130 nm was observed resulting from the protonation of the PDEAEMA segment. Moreover, in vitro drug release behaviors of the resulting polymer assemblies at different pH values were also investigated to evaluate their potential as sustained release drug carriers. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132 , 42183.
研究领域:
高分子化学
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材料科学
·
药剂学
✓ 已验证
产品关联
DOI
高影响因子
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