资源类型

期刊论文 1134

会议视频 25

会议信息 4

年份

2024 2

2023 175

2022 179

2021 193

2020 95

2019 42

2018 28

2017 51

2016 33

2015 37

2014 48

2013 43

2012 22

2011 27

2010 44

2009 31

2008 22

2007 39

2006 3

2005 2

展开 ︾

关键词

SARS-CoV-2 7

微波散射计 5

碳中和 5

COVID-19 4

Cu(In 4

HY-2 4

2019 3

2型糖尿病 3

GPS 3

Ga)Se2 3

HY-2 卫星 3

HY-2A卫星 3

代谢与免疫 3

光催化 3

工程管理 3

微波辐射计 3

营养健康 3

CCS 2

CO2利用 2

展开 ︾

检索范围:

排序: 展示方式:

Controlled drug release of 5-amino salicylic acid by poly(2-hydroxyethylmethacrylate) grafted agar

G. Usha RANI,Kartick Prasad DEY,Srijita BHARTI,Sumit MISHRA

《化学科学与工程前沿(英文)》 2014年 第8卷 第4期   页码 465-470 doi: 10.1007/s11705-014-1452-8

摘要: The utilization of poly (2-hydroxyethylmethacrylate) grafted agar (Ag-g-P(HEMA)) as a matrix for the controlled release of 5-aminosalicylic acid was investigated. Grafted copolymers of 2-hydroxyethylmethacrylate (HEMA) monomers on agar were synthesized by microwave assisted method. drug release studies were performed at pH values of 2 and 7 in order to investigate the possibility of pH triggered release for colon targeted drug delivery. Further, the percent grafting . (the time taken for release of 50% of the enclosed drug) value was studied and the results indicate that it may be possible to develop a programmable drug release matrix based on grafted polysaccharide. Ag-g-P(HEMA) appears to be a useful matrix for controlled release.

关键词: agar     controlled drug release     5-Amino salicylic acid     poly(2-hydroxyethylmethacrylate) grafted agar    

Microwave assisted synthesis of poly(2-hydroxyethylmethacrylate) grafted agar (Ag-g-P(HEMA)) and its

Gautam SEN, G. Usha RANI, Sumit MISHRA

《化学科学与工程前沿(英文)》 2013年 第7卷 第3期   页码 312-321 doi: 10.1007/s11705-013-1344-3

摘要: Poly(2-hydroxyethylmethacrylate) chains were grafted onto the backbone of agar using a microwave assisted method involving a combination of microwave irradiation and ceric ammonium nitrate to initiate the grafting reaction. The synthesized graft copolymers were characterized by intrinsic viscosity measurements, Fourier transform infrared spectroscopy, elemental analysis (C, H, N, O and S) and scanning electron microscopy. Ag-g-P(HEMA)-2 showed a much higher flocculation efficacy than agar. The optimized dosage of flocculation for Ag-g-P(HEMA)-2 in the wastewater was found to be 0.75 ppm. Compared to agar, Ag-g-P(HEMA)-2 was found to considerably reduce the pollutant load in the wastewater.

关键词: agar     flocculant     microwave assisted synthesis     jar test protocol     poly(HEMA) grafted agar     wastewater treatment    

Studies on the rheological, phase morphologic, thermal and mechanical properties of poly(trimethyleneterephthalate)/ethylene propylene diene monomer copolymer grafted with maleic anhydride/metallocene

RUN Mingtao, SONG Hongzan, WANG Yingjin, YAO Chenguang, GAO Jungang

《化学科学与工程前沿(英文)》 2007年 第1卷 第3期   页码 238-245 doi: 10.1007/s11705-007-0043-3

摘要: The rheological, phase morphologic, thermal and mechanical properties of poly(trimethylene terephthalate)/metallocene polyethylene (PTT/mPE) blends in the presence of ethylene propylene diene monomer copolymer grafted with maleic anhydride (EPDM--MAH) as compatibilizer are studied by means of a capillary rheometer, scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and thermogravimetric analyzer (TGA). Results suggest that the compatibility of PTT/mPE blends is improved greatly after the addition of a compatibilizer. The radius of the dispersed phase in the system decreases greatly when the compatibilizer is added into the blend. When the amount of compatibilizer exceeds 8 wt-%, the size of dispersed phase becomes larger again. This phenomena could be attributed to the higher viscosity of the EPDM--MAH phase, which is dispersed more difficulty in the PTT phase of lower viscosity, thus the mixing efficiency is apparently decreased during the melt blending process. Moreover, the melt viscosity of the blend reaches the maximal value in case of 4 wt-% compatibilizer content, above which it would decrease again. This result is associated with the generation of more and bigger dispersed phase inside the bulk phase, thus the grafting efficiency at the interface is decreased, which could result in lower viscosity. The DSC results suggest that the mPE component shows a nucleating effect, and could increase the overall degree and rate of PTT crystallization, while the addition of a compatibilizer might slightly diminish these effects. In addition, the blend with 4 wt-% compatibilizer shows the best thermal stability. Furthermore, the Izod impact strength and the tensile strength at room temperature of the blend are also markedly improved by the addition of a 4 8 wt-% compatibilizer.

关键词: /metallocene polyethylene     presence     rheological     phenomena     trimethylene terephthalate    

forward osmosis membranes with substrate layer composed of polysulfone blended with PEG or polysulfone grafted

Baicang Liu,Chen Chen,Pingju Zhao,Tong Li,Caihong Liu,Qingyuan Wang,Yongsheng Chen,John Crittenden

《化学科学与工程前沿(英文)》 2016年 第10卷 第4期   页码 562-574 doi: 10.1007/s11705-016-1588-9

摘要: To advance commercial application of forward osmosis (FO), we investigated the effects of two additives on the performance of polysulfone (PSf) based FO membranes: one is poly(ethylene glycol) (PEG), and another is PSf grafted with PEG methyl ether methacrylate (PSf-g-PEGMA). PSf blended with PEG or PSf-g-PEGMA was used to form a substrate layer, and then polyamide was formed on a support layer by interfacial polymerization. In this study, NaCl (1 mol?L ) and deionized water were used as the draw solution and the feed solution, respectively. With the increase of PEG content from 0 to 15 wt-%, FO water flux declined by 23.4% to 59.3% compared to a PSf TFC FO membrane. With the increase of PSf-g-PEGMA from 0 to 15 wt-%, the membrane flux showed almost no change at first and then declined by about 52.0% and 50.4%. The PSf with 5 wt-% PSf-g-PEGMA FO membrane showed a higher pure water flux of 8.74 L?m ?h than the commercial HTI membranes (6–8 L?m ?h ) under the FO mode. Our study suggests that hydrophobic interface is very important for the formation of polyamide, and a small amount of PSf-g-PEGMA can maintain a good condition for the formation of polyamide and reduce internal concentration polarization.

关键词: thin-film composite     forward osmosis     amphiphilic copolymer     interfacial polymerization     poly(ethylene glycol)    

Investigation of nanostructure of konjac-based water absorbents with atomic force microscopy

Shengrong GENG, Ruotai LIN, Mingli CHEN, Shaoyang LIU, Yifen WANG,

《化学科学与工程前沿(英文)》 2009年 第3卷 第4期   页码 357-362 doi: 10.1007/s11705-009-0245-y

摘要: Atomic force microscopy technology is gradually spreading to almost all aspects, including food science and technology, since it was first invented in 1986. In this study, this powerful instrument was applied to image nanostructures of three water absorbents—original konjac powder, konjac powder grafted with acrylic acid using Co γ-irradiation and regenerated grafted powder. Water absorption capacities and the rates of the three absorbents were also determined in this work. Original konjac powder could only absorb 60 times (w/w) of water, while 270 times for the grafted absorbent and 360 times for the regenerated absorbent. The initial water absorption rates in both tap and distilled water were high, but the rate decreased steeply as time elapsed. After 20min, the absorbent was close to saturated status. These physical properties were in accordance with the nanostructures of these three water absorbents.

关键词: regenerated grafted     -irradiation     grafted     grafted absorbent     accordance    

Preparation and characterization of poly (vinylidene fluoride)/TiO

Weiying LI, Xiuli SUN, Chen WEN, Hui LU, Zhiwei WANG

《环境科学与工程前沿(英文)》 2013年 第7卷 第4期   页码 492-502 doi: 10.1007/s11783-012-0407-x

摘要: Poly(vinylidene fluoride) (PVDF)/titanium dioxide (TiO ) hybrid membranes were prepared using nano-TiO as the modifier, and characterized by Transmission Electron Microscope (TEM), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), atomic force microscope (AFM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The characterization results demonstrated that nano-sized TiO particles dispersed homogeneously within the PVDF matrix, contributing to more hydroxyls and smoother surfaces. Moreover, permeate flux, retention factor, porosity, contact angle and anti-fouling tests were carried out to evaluate the effect of TiO concentration on the performance of PVDF membranes. Among all the prepared membranes, PVDF/TiO membrane containing 10 vol.% TiO exhibited the best hydrophilicity with an average pure water flux up to 237 L·m ·h , higher than that of unmodified PVDF membranes (155 L·m ·h ). Besides, the bovine serum albumin rejection of the hybrid membrane was improved evidently from 52.3% to 70.6%, and the contact angle was significantly lowered from 83° to 60°, while the average pore size and its distribution became smaller and narrower.

关键词: poly(vinylidene fluoride) (PVDF) membrane     nano-TiO2     anti-fouling performance     water treatment    

Design and analysis of dual fuel methanol-power poly-generation

Minghua WANG , Zheng LI , Weidou NI ,

《能源前沿(英文)》 2009年 第3卷 第3期   页码 341-347 doi: 10.1007/s11708-009-0023-z

摘要: A dual fuel head poly-generation flowsheet was designed based on coal gas and coke oven gas. To help clearly understand the system performance, a 1.2×10−3.2×10kg methanol and 274―496MW power poly-generation system was simulated by using the commercially available software ASPEN Plus and GT Pro. The technology scheme, the operating parameters, and the efficiency of the system were also analyzed and evaluated, which will be used for building industrial devices.

关键词: dual fuel     methanol-power poly-generation     CO2 and CH4 reforming     splitting ratio    

Synthesis and characterization of biodegradable thermoplastic elastomers derived from N′,N-bis (2-carboxyethyl)-pyromellitimide, poly(butylene succinate) and polyethylene glycol

Jiaojiao Shang, Guo Yao, Ronghui Guo, Wei Zheng, Long Gu, Jianwu Lan

《化学科学与工程前沿(英文)》 2018年 第12卷 第3期   页码 457-466 doi: 10.1007/s11705-018-1716-9

摘要:

Biodegradable poly(ether-imide-ester) elastomers were synthesized from succinic acid, 1,4-butanediol, polyethylene glycol 1000 and N′,N-bis(2-carboxyethyl)-pyromellitimide which was derived from pyromellitic dianhydride and glycine. The chemical structures, crystallinities, thermal stabilities, mechanical properties, hydrophilicities and biodegradabilities of these elastomers were investigated. The hard segments of the linear aliphatic poly(ether-ester) exhibited monoclinic chain packing. Increasing the amount of aromatic bisimide moieties in the poly(ether-ester) reduced the crystallinity of the material and improved the thermal stability and tensile strength of the elastomers. In addition, introducing a suitable amount of aromatic bisimide moieties into the poly(ether-ester) backbones endowed the elastomers with improved biodegradability but too many aromatic bisimide groups reduced the biodegradability of the elastomers.

关键词: thermoplastic elastomers     biodegradability     thermo-stability     mechanical property     aromatic bisimide moiety    

Ultrafast-laser-treated poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) electrodes with enhanced

《化学科学与工程前沿(英文)》 2023年 第17卷 第2期   页码 206-216 doi: 10.1007/s11705-022-2203-x

摘要: Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is an important organic electrode for solution-processed low-cost electronic devices. However, it requires doping and post-solvent treatment to improve its conductivity, and the chemicals used for such treatments may affect the device fabrication process. In this study, we developed a novel route for exploiting ultrafast lasers (femtosecond and picosecond laser) to simultaneously enhance the conductivity and transparency of PEDOT:PSS films and fabricate patterned solution-processed electrodes for electronic devices. The conductivity of the PEDOT:PSS film was improved by three orders of magnitude (from 3.1 to 1024 S·cm–1), and high transparency of up to 88.5% (average visible transmittance, AVT) was achieved. Raman and depth-profiling X-ray photoelectron spectroscopy revealed that the oxidation level of PEDOT was enhanced, thereby increasing the carrier concentration. The surface PSS content also decreased, which is beneficial to the carrier mobility, resulting in significantly enhanced electrical conductivity. Further, we fabricated semitransparent perovskite solar cells using the as-made PEDOT:PSS as the transparent top electrodes, and a power conversion efficiency of 7.39% was achieved with 22.63% AVT. Thus, the proposed route for synthesizing conductive and transparent electrodes is promising for vacuum and doping-free electronics.

关键词: PEDOT:PSS     ultrafast laser     transparent electrode     ST-PSCs     patterning    

Biodegradable polymethacrylic acid grafted psyllium for controlled drug delivery systems

Ranvijay KUMAR, Kaushlendra SHARMA

《化学科学与工程前沿(英文)》 2013年 第7卷 第1期   页码 116-122 doi: 10.1007/s11705-013-1310-0

摘要: Polymethacrylic acid (PMA) was synthesized on the backbone of psyllium (Psy) by a microwave assisted method to prepare polymeric grafted materials designated as (Psy- -PMA). Various grades of Psy- -PMA were prepared by changing the degree of grafting from 35%–58% and the materials were then made into tablets. Swelling and biodegradability studies of the tablets were carried out. Acetyl salicylic acid was incorporated in the various Psy- -PMA samples and tablets were prepared to study the in vitro drug release in acidic (pH= 4), neutral (pH= 7), and basic (pH= 9) media. In the acidic medium, the swelling was more than 1300%. In addition, the biodegradable Psy- -PMA had the highest drug release in the acidic medium. This may be attributed to Fickian diffusion since the drug and the medium in which it was released have the same acidic nature.

关键词: psyllium     acetyl salicylic acid     in-vitro drug release     swelling     biodegradation    

Hydrophilic modification of poly(aryl sulfone) membrane materials toward highly-efficient environmental

《化学科学与工程前沿(英文)》 2022年 第16卷 第5期   页码 614-633 doi: 10.1007/s11705-021-2115-1

摘要: Poly(aryl sulfone) as a typical membrane material has been widely used due to excellent mechanical, chemical and thermal stability. However, the inherent hydrophobicity of poly(aryl sulfone) based membranes bears with the fouling issue during applications, which makes the membrane tending to adsorb contaminants on the surface so as to result in decreased separation performance and lifetime. In this critical review, we give a comprehensive overview on characterizations of hydrophilic membrane and diverse hydrophilic modification approaches of poly(aryl sulfone) membranes, predominantly including bulky, blending and surface modification technology. The discussions on the different modification methods have been provided in-depth. Besides, focusing on modification methods and performance of modified membranes, the related mechanisms for the performance enhancement are discussed too. At last, the perspectives are provided to guide the future directions to develop novel technology to manipulate the hydrophilicity of poly(aryl sulfone) membranes toward diverse practical and multi-functional applications.

关键词: poly(aryl sulfone)     membrane separations     modification     hydrophilicity     water treatment    

Genomic and metabolomic analysis of with enhanced poly--glutamic acid production through atmospheric

《化学科学与工程前沿(英文)》 2022年 第16卷 第12期   页码 1751-1760 doi: 10.1007/s11705-022-2211-x

摘要: Poly-γ-glutamic acid is an extracellular polymeric substance with various applications owing to its valuable properties of biodegradability, flocculating activity, water solubility, and nontoxicity. However, the ability of natural strains to produce poly-γ-glutamic acid is low. Atmospheric and room temperature plasma was applied in this study to conduct mutation breeding of Bacillus licheniformis CGMCC 2876, and a mutant strain M32 with an 11% increase in poly-γ-glutamic acid was obtained. Genome resequencing analysis identified 7 nonsynonymous mutations of ppsC encoding lipopeptide synthetase associated with poly-γ-glutamic acid metabolic pathways. From molecular docking, more binding sites and higher binding energy were speculated between the mutated plipastatin synthase subunit C and glutamate, which might contribute to the higher poly-γ-glutamic acid production. Moreover, the metabolic mechanism analysis revealed that the upregulated amino acids of M32 provided substrates for glutamate and promoted the conversion between L- and D-glutamate acids. In addition, the glycolytic pathway is enhanced, leading to a better capacity for using glucose. The maximum poly-γ-glutamic acid yield of 14.08 g·L–1 was finally reached with 30 g·L–1 glutamate.

关键词: ARTP mutagenesis     Bacillus licheniformis     poly-γ-glutamic acid     metabolomics    

Benzenesulfonic acid-grafted UIO-66 with improved hydrophobicity as a stable Brønsted acid catalyst

《化学科学与工程前沿(英文)》 2023年 第17卷 第10期   页码 1389-1398 doi: 10.1007/s11705-022-2285-5

摘要: Hydrothermal and catalytic stability of UIO-66 MOFs with defective structures are critical aspects to be considered in their catalytic applications, especially under the conditions involving water, moisture and/or heat. Here, we report a facile strategy to introduce the macromolecular acid group to UIO-66 to improve the stability of the resulting UIO-66−PhSO3H MOF in aqueous phase catalysis. In detail, UIO-66−PhSO3H was obtained by grafting benzenesulfonic acid on the surface of the pristine UIO-66 to introduce the hydrophobicity, as well as the Brønsted acidity, then assessed using catalytic hydrolysis of cyclohexyl acetate (to cyclohexanol) in water. The introduction of hydrophobic molecules to UIO-66 could prevent the material from being attacked by hydroxyl polar molecules effectively, explaining its good structural stability during catalysis. UIO-66−PhSO3H promoted the conversion of cyclohexyl acetate at ca. 87%, and its activity and textural properties were basically intact after the cyclic stability tests. The facile modification strategy can improve the hydrothermal stability of UIO-66 significantly, which can expand its catalytic applications in aqueous systems.

关键词: metal−organic frameworks (MOFs)     UIO-66     hydrolysis of cyclohexyl acetate     hydrophobicity     Brønsted acidity    

Preparation of copolymer-grafted mixed-mode resins for immunoglobulin G adsorption

Shenggang Chen, Tao Liu, Ruiqi Yang, Dongqiang Lin, Shanjing Yao

《化学科学与工程前沿(英文)》 2019年 第13卷 第1期   页码 70-79 doi: 10.1007/s11705-018-1745-4

摘要: The mixed-mode resins for protein adsorption have been prepared by a novel strategy, copolymer grafting. Specially, the copolymer-grafted resins CG-M-A with two functional groups, 5-amino-benzimidazole (ABI) and methacryloxyethyltrimethyl ammonium chloride (METAC), have been prepared through surface-initiated activator generated by electron transfer for atom transfer radical polymerization of METAC and glycidyl methacrylate (GMA), followed by a ring-open reaction to introduce ABI. The charge and hydrophobicity of CG-M-A resins could be controlled by manipulating the addition of METAC and GMA/ABI. Besides, METAC and ABI provided positive effects together in both protein adsorption and elution: dynamic binding capacity of human Immunoglobulin G (hIgG) onto CG-M-A resin with the highest ligand ratio of METAC to ABI is 46.8 mg·g at pH 9 and the elution recovery of hIgG is 97.0% at pH 5. The separation experiment showed that purity and recovery of monoclonal antibody from cell culture supernatant are 96.0% and 86.5%, respectively, indicating that copolymer-grafted mixed-mode resins could be used for antibody purification.

关键词: atom transfer radical polymerization     copolymer-grafting     mixed-mode resin     protein adsorption    

Effect of polyethylene glycol on the crystallization, rheology and foamability of poly(lactic acid) containing

《化学科学与工程前沿(英文)》 2023年 第17卷 第12期   页码 2074-2087 doi: 10.1007/s11705-023-2342-8

摘要: In this study, the rheological properties, crystallization and foaming behavior of poly(lactic acid) with polyamide 6 nanofibrils were examined with polyethylene glycol as a compatibilizer. Polyamide 6 particles were deformed into nanofibrils during drawing. For the 10% polyamide 6 case, polyethylene glycol addition reduced the polyamide 6 fibril diameter from 365.53 to 254.63 nm, owing to the smaller polyamide 6 particle size and enhanced interface adhesion. Rheological experiments revealed that the viscosity and storage modulus of the composites were increased, which was associated with the three-dimensional entangled network of polyamide 6 nanofibrils. The presence of higher aspect ratio polyamide 6 nanofibrils substantially enhanced the melt strength of the composites. The isothermal crystallization kinetics results suggested that the polyamide 6 nanofibrils and polyethylene glycol had a synergistic effect on accelerating poly(lactic acid) crystallization. With the polyethylene glycol, the crystallization half-time reduced from 103.6 to 62.2 s. Batch foaming results indicated that owing to higher cell nucleation efficiency, the existence of polyamide 6 nanofibrils led to a higher cell density and lower expansion ratio. Furthermore, the poly(lactic acid)/polyamide 6 foams exhibited a higher cell density and expansion ratio than that of the foams without polyethylene glycol.

关键词: poly(lactic acid)     foaming     microfibrillation     rheological property     crystallization    

标题 作者 时间 类型 操作

Controlled drug release of 5-amino salicylic acid by poly(2-hydroxyethylmethacrylate) grafted agar

G. Usha RANI,Kartick Prasad DEY,Srijita BHARTI,Sumit MISHRA

期刊论文

Microwave assisted synthesis of poly(2-hydroxyethylmethacrylate) grafted agar (Ag-g-P(HEMA)) and its

Gautam SEN, G. Usha RANI, Sumit MISHRA

期刊论文

Studies on the rheological, phase morphologic, thermal and mechanical properties of poly(trimethyleneterephthalate)/ethylene propylene diene monomer copolymer grafted with maleic anhydride/metallocene

RUN Mingtao, SONG Hongzan, WANG Yingjin, YAO Chenguang, GAO Jungang

期刊论文

forward osmosis membranes with substrate layer composed of polysulfone blended with PEG or polysulfone grafted

Baicang Liu,Chen Chen,Pingju Zhao,Tong Li,Caihong Liu,Qingyuan Wang,Yongsheng Chen,John Crittenden

期刊论文

Investigation of nanostructure of konjac-based water absorbents with atomic force microscopy

Shengrong GENG, Ruotai LIN, Mingli CHEN, Shaoyang LIU, Yifen WANG,

期刊论文

Preparation and characterization of poly (vinylidene fluoride)/TiO

Weiying LI, Xiuli SUN, Chen WEN, Hui LU, Zhiwei WANG

期刊论文

Design and analysis of dual fuel methanol-power poly-generation

Minghua WANG , Zheng LI , Weidou NI ,

期刊论文

Synthesis and characterization of biodegradable thermoplastic elastomers derived from N′,N-bis (2-carboxyethyl)-pyromellitimide, poly(butylene succinate) and polyethylene glycol

Jiaojiao Shang, Guo Yao, Ronghui Guo, Wei Zheng, Long Gu, Jianwu Lan

期刊论文

Ultrafast-laser-treated poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) electrodes with enhanced

期刊论文

Biodegradable polymethacrylic acid grafted psyllium for controlled drug delivery systems

Ranvijay KUMAR, Kaushlendra SHARMA

期刊论文

Hydrophilic modification of poly(aryl sulfone) membrane materials toward highly-efficient environmental

期刊论文

Genomic and metabolomic analysis of with enhanced poly--glutamic acid production through atmospheric

期刊论文

Benzenesulfonic acid-grafted UIO-66 with improved hydrophobicity as a stable Brønsted acid catalyst

期刊论文

Preparation of copolymer-grafted mixed-mode resins for immunoglobulin G adsorption

Shenggang Chen, Tao Liu, Ruiqi Yang, Dongqiang Lin, Shanjing Yao

期刊论文

Effect of polyethylene glycol on the crystallization, rheology and foamability of poly(lactic acid) containing

期刊论文