JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY
·
2015
·Vol. 54
·期 3
·368-380
·
IF 3.113
Jingang Li,Yixin Xiang,Sixun Zheng
In this contribution, we reported the synthesis of a hyperbranched block copolymer composed of poly(ε-caprolactone) (PCL) and polystyrene (PS) subchains. Toward this end, we first synthesized an α-alkynyl- and ω,ω′-diazido-terminated PCL- b -(PS) 2 macromonomer via the combination of ring-opening polymerization and atom transfer radical polymerization. By the use of this AB 2 macromonomer, the hyperbranched block copolymer ( h -[PCL- b -(PS) 2 ]) was synthesized via a copper-catalyzed Huisgen 1,3-dipolar cycloaddition (i.e., click reaction) polymerization. The hyperbranched block copolymer was characterized by means of 1 H nuclear magnetic resonance spectroscopy and gel permeation chromatography. Both differential scanning calorimetry and atomic force microscopy showed that the hyperbranched block copolymer was microphase-separated in bulk. While this hyperbranched block copolymer was incorporated into epoxy, the nanostructured thermosets were successfully obtained; the formation of the nanophases in epoxy followed reaction-induced microphase separation mechanism as evidenced by atomic force microscopy, small angle X-ray scattering, and dynamic mechanical thermal analysis. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54 , 368–380
研究领域:
高分子化学
·
材料科学
·
纳米结构功能材料
·
聚合物自组装
·
热固性树脂改性
✓ 已验证
DOI
高影响因子
FUEL PROCESSING TECHNOLOGY
·
2019
·
IF 4.507
Haonan Qu,Bingyi Liu,Guohua Gao,Yiming Ma,Yanmei Zhou,Hua Zhou,Li Li,Yonghong Li,Shengjian Liu
Levulinic acid (LA) is a versatile key building block in the conversion of carbohydrates and it is an important basic chemical with various potential uses. MIL-100(Fe) loading with insoluble lysine functionalized phosphotungstic acid (Lys-PM 2 ) as heterogeneous catalysts have been synthesized for the conversion of glucose to LA in water. The optimized yield of LA is obtained by using Lys-PM 2 to catalyze glucose conversion is comparable to the majority of effective catalysts. The highest yield of LA (57.9%) is obtained at 150 °C for 9 h with 100 mg glucose and 25 mg Lys-PM 2 , since the Brønsted acidity and Lewis acidity of Lys-PM 2 . And the catalyst is able to recycle at least four times. It demonstrates the potential of Lys-PM 2 for the conversion of biomass.
研究领域:
催化化学
·
绿色化学
·
生物质能源
·
有机转化
·
材料化学
·
可持续化学
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2014
·
IF 2.354
Tianxiang Yin,Miao Qin,Weiguo Shen
The interactions of Gemini surfactants 1-dodecyl- N , N ′-[(1,4-dioxo-1,4-butanediyl)bis(oxy-2,1-ethanediyl)]bis[ N , N ′-dimethylammonium]dibromide (12-su-12) and 1-dodecyl- N , N ′-[((2 E )-1,4-dioxo-2-butene-1,4-diyl)bis(oxy-2,1-ethanediyl)]bis[ N , N ′-dimethylammonium]dibromide (12-fo-12) and the corresponding single-chain surfactant 1-dodecyl- N -[2-(acetyloxy)ethyl]- N , N -dimethyl ammonium bromide (DTAAB) with bovine serum albumin (BSA) were investigated by conductometry, fluorimetry, UV–vis and CD spectrometry, and dynamic light scattering. It was found that the bindings of all three surfactants to BSA were cooperatively driven by electrostatic and hydrophobic interactions. The Gemini surfactants, carrying more charges and hydrophobic tails, showed stronger interactions with BSA than the single-chain surfactant. The presence of the double bond in the spacer of 12-fo-12 enhanced the interaction between the surfactant and BSA and also significantly varied the binding sites as compared to 12-su-12 and DTAAB, which indicated an important role of the property of the spacer in the interaction between the surfactant and BSA.
研究领域:
生物物理化学
·
分子生物学
·
药物递送
·
蛋白质科学
·
纳米医学
✓ 已验证
DOI
高影响因子
MICROCHEMICAL JOURNAL
·
2014
·
IF 3.583
Haiyun Zhai,Jiangmei Li,Zuanguang Chen,Zihao Su,Zhenping Liu,Xiao Yu
A simple glass/PDMS microfluidic chip for on-line sample pretreatment and contactless conductivity detection, which consisted of a 0.17 mm-thick glass cover and a PDMS substrate embedded with an SPE monolithic column, was presented in this paper. Using this integrated microchip system, sample extraction, injection, separation and detection were automatically performed in sequence. A sample of auramine O was concentrated by molecularly imprinted SPE (MISPE), eluted to sample reservoir, and injected by electromigration into separation channel for electrophoresis separation and contactless conductivity detection, with the calculated detection limit (S/N = 3) being 2.5 μg mL − 1 . The monolithic column was utilized to quantitatively extract auramine O , yielding an on-line enrichment factor of about 12. The microchip system is reliable and applicable to the analysis of auramine O in food sample.
研究领域:
分析化学
·
微流控技术
·
食品安全
·
分子印迹技术
·
电泳学
·
生物医学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2019
·
IF 4.561
Xiao-Qian Wei,Wan-Ju Zhang,Lu Lai,Ping Mei,Li-Mei Wu,Yan-Qun Wang
The effects of cationic surfactants on the properties of Pickering emulsions stabilized by silica nanoparticles (nano-SiO 2 ) were investigated. The zeta potential , three-phase contact angle ( θ ), and dynamic interfacial tension (DIT) were measured to analyze the interaction between hydrophilic nano-SiO 2 and four different cationic surfactants (i.e., dodecyltrimethylammonium bromide [DTAB], bis-quaternary ammonium salts [BQAS-12], multiple quaternary ammonium salts [MQAS-12], and dimethyldioctadecylammonium bromide [DDAB-18]). All these surfactants can naturally improve the stability of Pickering emulsions induced by hydrophilic nano-SiO 2 . The nano-SiO 2 /MQAS-12 mixtures exhibited the best ability to stabilize the O/W emulsions, followed by nano-SiO 2 /BQAS-12 mixtures. The nano-SiO 2 /DDAB-18 mixtures can induce emulsion inversion from O/W to W/O. All emulsions exhibited excellent salt tolerance and acid-base resistance properties. Determining the zeta potential showed that nano-SiO 2 had the highest negative charge at the pH of 9.5. Thus, the surfactant molecules can be adsorbed remarkably on the nano-SiO 2 surface. Modification with different cationic surfactants can significantly increase the θ value of nano-SiO 2 , but the bilayers for DTAB-12, BQAS-12, and MQAS-12, except for DDAB-18, were adsorbed. DIT curves indicated that competitive adsorption of the surfactants occurred between the oil/water interface and nano-SiO 2 surface. The competitive adsorption of MQAS-12 was stronger than those of BQAS-12 and DTAB-12. The nano-SiO 2 /DDAB-18 mixture had an apparent induction region and required a considerable amount of time to reach equilibrium. The modified nano-SiO 2 was also not adsorbed in the oil/water interface spontaneously, which may be due to the large size of particles compared with small surfactant molecules.
研究领域:
胶体与界面化学
·
纳米材料科学
·
乳液工程
·
物理化学
·
表面科学
✓ 已验证
DOI
高影响因子
MATERIALS RESEARCH BULLETIN
·
2012
·Vol. 47
·期 11
·3277-3282
·
IF 2.105
Jing Bo Zhang,Xiao Ning Li,Shou Li Bai,Rui Xian Luo,Ai Fan Chen,Yuan Lin
Well-crystallized one-dimensional (1D) SnO 2 nanobelts were in situ prepared using a simple water-assisted chemical vapor deposition (CVD) method. The small Sn particles with Au-modifications were used as source materials instead of big size Sn grains to ensure the high yield of SnO 2 belts. The Au layer was modified on the small Sn particles by treating Sn powders in HAuCl 4 solution combined with the UV irradiation. The as-prepared SnO 2 nanobelts were characterized by SEM, HRTEM, XRD, EDS and XPS. These results indicate that the growth temperature plays an important role in controlling the length-to-width ratio of nanobelts. The length-to-width ratio decreases with the growth temperature from 850 °C to 1000 °C. The nanobelts prepared at 850 °C shows a single-crystalline tetragonal rutile phase with a high length-to-width ratio (approximately tens of microns in length and 40–70 nm in width). However, below 850 °C, nanobelts cannot be formed. The as-prepared nanobelts exhibited excellent sensing properties compared with SnO 2 nanoparticles and high sensing selectivity towards NO 2 . The high sensing selectivity to NO 2 is attributed to the oxygen vacancies presenting in the as-prepared nanobelts.
研究领域:
材料科学
·
纳米技术
·
传感器学
·
无机化学
·
半导体材料
✓ 已验证
DOI
高影响因子
MACROMOLECULAR MATERIALS AND ENGINEERING
·
2017
·Vol. 303
·期 2
·1700396
·
IF 2.863
Zhihui Qin,Rui Niu,Chenjue Tang,Jun Xia,Feng Ji,Dianyu Dong,Haitao Zhang,Shuo Zhang,Junjie Li,Fanglian Yao
A novel type of physical hydrogel based on dual-crosslinked strategy is successfully synthesized by micellar copolymerization of stearyl methacrylate, acrylamide, and acrylic acid, and subsequent introduction of Fe 3+ . Strong hydrophobic associations among poly(stearyl methacrylate) blocks form the first crosslinking point and ionic coordination bonds between carboxyl groups and Fe 3+ serve as the second crosslinking point. The mechanical properties of the hydrogel can be tuned in a wide range by controlling the densities of two crosslinks. The optimal hydrogel shows excellent mechanical properties (tensile strength of ≈6.8 MPa, elastic modulus of ≈8.0 MPa, elongation of ≈1000%, toughness of 53 MJ m −3 ) and good self-recovery property. Furthermore, owing to stimuli responsiveness of physical interaction, this hydrogel also shows a triple shape memory effect. The combination of two different physical interactions in a single network provides a general strategy for designing of high-strength hydrogels with functionalities.
研究领域:
高分子材料科学
·
生物医用材料
·
组织工程
·
智能响应材料
·
软物质物理
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2017
·Vol. 44
·期 2
·1731-1736
·
IF 2.986
Jingbo Yu,Qian Zhang,Yi Gu,Anxian Lu
In this study, phosphate glasses embedded with Fe 2 O 3 quantum dots were prepared via a conventional melt quenching technology with further heat treatment. The effect of Fe 2 O 3 content on the structural, optical and magneto-optical properties was investigated. The results showed that the addition of Fe 2 O 3 had no obvious influence on the structure units that built up the host glass and the amorphous nature of glass. In the glass matrix , the existence of Fe 2 O 3 quantum dots was confirmed by high resolution transmission electron microscope . Meanwhile, optical study clearly demonstrated a red shift in optical cut-off wavelength resulted from the size quantization effect. The highest Verdet constant (22.33°/T-cm) was measured for the glass containing 1 mol% Fe 2 O 3 , which was ~ 7 times higher than that of the glass matrix. As the increment of Fe 2 O 3 contents, a phase evolution of Fe 2 O 3 quantum dots from amorphous phase to γ-Fe 2 O 3 phase was recorded due to the Ostwald Ripening effect. Interestingly, a concentration quenching phenomenon in Verdet constant was observed along with the phase evolution of Fe 2 O 3 quantum dots. When the content of Fe 2 O 3 is up to 2 mol%, the glass exhibited paramagnetism with the Verdet constant of − 2.833°/T-cm. This finding can provide a new idea for the development of quantum dot embedded magneto-optical glass.
研究领域:
材料科学
·
磁光材料
·
纳米材料
·
无机非金属材料
·
光学玻璃
·
凝聚态物理
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2018
·Vol. 43
·期 45
·20712-20720
·
IF 4.229
Biyao Jin,Yiqi Li,Lianhua Zhao
Bimetallic PdV/C nanoparticles have been synthesized by phase-transfer method for catalyzing the oxygen reduction reaction (ORR) in alkaline electrolytes . PdV/C nanoparticles with different V contents are spherical with a mean diameter of 3–4 nm, and the addition of V expands the lattice parameter of Pd as shown by XRD . XPS analysis indicated the binding energy of Pd 0 3d peak increased by ca. 1 eV. Density functional theory (DFT) calculations results shows d-band center of Pd down-shift after V-doping. Based on the electrocatalytic results, introducing V can improve the catalytic activity for ORR, methanol crossover tolerance and stability. Especially, Pd 4 V/C shows higher initial potential (E onset = 1.027 V), excellent methanol crossover tolerance (98.03% retained) and long-term stability (81.30% retained), which are comparable with Pt/C JM . This work provides a new method of synthesizing PdV/C nanoparticles , which have the potential to be used as the cathode electrocatalysts for fuel cells.
研究领域:
材料科学
·
电化学
·
纳米催化
·
能源材料
·
燃料电池
·
物理化学
·
表面科学
✓ 已验证
DOI
高影响因子
Laser & Photonics Reviews
·
2024
·Vol. 19
·期 1
·2401012
·
IF 9.8
Pengcheng Jian,Maohua Chen,Dongyan Li,Yongming Zhao,Weijie Liu,Yuang Luo,Xiantai Tian,Meng Peng,Xing Zhou,Jiangnan Dai,Feng Wu,Changqing Chen
The extraordinary mechanical compliance of 2D molybdenum disulfide (MoS 2 ) makes it an ideal candidate for strain modulation of various electrical and optical properties. However, developing facile methods for accurate and stable engineering of strain still remains a major challenge. Here, a novel and effective method is demonstrated for introducing periodic strain into monolayer MoS 2 by direct growth on nano-patterned sapphire substrates (NPSS). A mixed aqueous solution of Na 2 MoO 4 and NaOH is spin-coated on the NPSS and sulfurated in one step by chemical vapor deposition (CVD). Highly oriented monolayer MoS 2 single-crystal nanosheets with high quality and few sulfur vacancies are achieved conformally on the NPSS via a liquid-mediated growth mode. Notably, the periodically distributed blue shift of the PL emission peak demonstrated periodic compressive strain is introduced into the nano-patterned MoS 2 via the thermal expansion difference between MoS 2 and substrates. Furthermore, photodetectors fabricated using the nano-patterned monolayer MoS 2 exhibit a high photo-to-dark current ratio (PDCR) over 10 6 , an excellent detectivity of 5.4 × 10 13 Jones, and a fast photoresponse of 7.7 ms, owing to the strain-induced back-to-back built-in electric field, enhanced light absorption by light-scattering effect and fewer S vacancy defects. The scanning imaging demonstration based on the single-pixel nano-patterned MoS 2 photodetector further confirms its great potential in image sensors. This work hereby presents a pathway for direct conformal growth of nano-patterned monolayer MoS 2 with precisely periodic strain, which should inspire the applications for high-performance optoelectronic devices via the strategy of patterned substrate engineering by the periodic nanostructures.
研究领域:
材料科学
·
纳米科技
·
光电子学
·
凝聚态物理
·
表面科学
·
半导体器件
✓ 已验证
DOI
高影响因子
Small
·
2022
·Vol. 18
·期 29
·2202622
·
IF 15.153
Hao Zhu,Zixuan Chen,Yun Chen,Jun-Jie Zhu
Quantifying the binding kinetics and affinities of protein–small molecule interactions is critical for biomarker validation, drug discovery, and deep understanding of various biological processes at the molecular-scale. Novel approaches are demanded as most common label-free techniques are mass-sensitive, which are not suitable for the detection of small molecule interactions. Here, an optical imaging platform is developed to measure the binding kinetics of both protein–small molecules and protein–ions based on monolayer MoS 2 , an ultra-thin 2D material whose optical absorption is extremely sensitive to charge. A model is established to calibrate the optical response due to the charged analyte binding and it is applied to quantify the interactions between abl1 kinase and different small-molecule inhibitors. Such a presented method is capable of distinguishing different inhibitors binding to a wild or mutated kinase, which provides guidance for drug evaluation and drug mechanism exploration. The binding kinetics of calcium ions to calmodulin is also measured, further broadening the application field of the method. In addition, the imaging capability allows mapping the local binding kinetics of the molecular interactions with a high resolution, which reveals visible spatial variability and offers a promising tool for studying heterogeneous local interfacial interactions.
研究领域:
分子生物学
·
药物发现
·
生物传感器
·
化学生物学
·
生物物理
·
转化医学
·
纳米生物技术
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2018
·
IF 4.439
Haihua Wang,Bei Li,Guiqiang Fei,Yiding Shen,Ke Zhu
We reported herein the synthesis of block copolymers and their application in the in-situ emulsion polymerization of waterborne poly (urethane-acrylate) (WPUA) nanoemulsions based on phase inversion process. The polymerizable surfmers containing terminal unsaturated double bonds (MSA-r) were successfully synthesized via catalytic chain transfer polymerization (CCTP). Random copolymer (MSA-t) prepared through radical polymerization was utilized as control. The structure, surface tension and aggregation behavior of surfmers were characterized. The phase inversion, formation and stability of WPUA nanoemulsions were systematically investigated. Effects of MSA-r surfmer content and BMA/MMA ratio on the water resistance and thermal stability of the corresponding films were also discussed. It was found that the phase inversion mechanism of PUA prepolymer in the presence of MSA-r surfmers is different from conventional polyurethane prepolymer. The addition of MSA-r and MSA-t surfmers alters the rheological behaviors of PUA prepolymer via PUA-surfmer interactions, as well as the phase inversion process. Compared with WPUA/MSA-t emulsion, WPUA/MSA-r nanoemulsion displayed improved stability at higher solid content. The minimum particle size of WPUA/MSA-r nanoemulsion was 88.7 nm and kept almost constant after 12-month storage, while the particle size of WPUA/MSA-t emulsion was 131.3 nm and increased to 178.9 nm. Moreover, the WPUA/MSA-r film possessed improved water resistance and thermal stability.
研究领域:
高分子化学
·
胶体与界面科学
·
材料化学
·
纳米材料
·
功能高分子
·
水性涂料
·
聚合物乳液
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）