COLLOIDS AND SURFACES B-BIOINTERFACES
·
2012
·
IF 3.456
Miao Wang,Jiang Yuan,Xiaobo Huang,Xianmei Cai,Li Li,Jian Shen
Grafting-from has proven to be a very effective way to create high grafting densities and well-controlled polymer chains on different kinds of surfaces. In this work, we aim to graft zwitterionic brush from cellulose membrane (CM) via ARGET-ATRP (Activator Regenerated by Electron Transfer ATRP) method indirectly for blood compatibility improvement. Characterization of the CM substrates before and after modification was carried out by attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), water contact angle measurements, X-ray photoelectron spectroscopy analysis, and atomic force microscopy, respectively. The results demonstrated zwitterionic brushes were successfully grafted on the CM surfaces, and the content of the grafted layer increased gradually with the polymerization time. The platelet adhesion, hemolytic test and plasma protein adsorption results indicated the cellulose membrane had significantly excellent blood compatibility featured on lower platelet adhesion and protein adsorption without causing hemolysis. The functionalized cellulose substrate could have a great potential usage for biomedical applications.
研究领域:
生物材料学
·
医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CELLULOSE
·
2025
·
IF 4.8
Zhao Yao,Wang Xueping,Li Bowen,Si Tian,Gao Xin,Peng Lincai,Zhang Heng
The cellulose catalytic oxidation system mainly comprises inorganic ion-based oxidants. Hence, the selective oxidation of C 6- primary hydroxy groups (C 6 -OH) of cellulose, catalyzed by piperidine free radicals, was limited to the homogeneous cellulosic system containing protic solvents or heterogeneous system. In this work, the use of the catalytic system containing 4-acetamido-2,2,6,6-tetramethylpiperidine 1-oxyl (4-AcNH-TEMPO) was extended to the cellulosic solution in N, N-dimethylacetamide (DMAc) and combined with chlorine dioxide. Results showed that the carboxyl content was 0.832 mmol/g. Meanwhile, the degree of polymerization decreased from 900 to 489. This study provides an effective route for the homogeneous selective oxidation of primary hydroxy groups in cellulose and explored its oxidation mechanism in DMAc solvent. Furthermore, studies showed that the reactive chlorine species- ClO·, Cl·, and ClO 2 played a crucial role in the oxidation process. The methodology developed here displayed great potential to be utilized to various biomolecules in aprotic solvents homogeneous system based on 4-AcNH-TEMPO as oxidation catalysts.
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
·
2015
·Vol. 16
·期 1
·1855-1872
·
IF 2.862
Chuanshi Shao,Lin Liu,Hongze Gang,Shizhong Yang,Bozhong Mu
Surfactin originated from genusBacillusis composed of a heptapeptide moiety bonded to the carboxyl and hydroxyl groups of a β-hydroxy fatty acid and it can be chemically modified to prepare the derivatives with different structures, owing to the existence of two free carboxyl groups in its peptide loop. This article presents the chemical modification of surfactin esterified with three different alcohols, and nine novel surfactin derivatives have been separated from products by the high performance liquid chromatography (HPLC). The novel derivatives, identified with Fourier transform infrared spectroscopy (FT-IR) and electrospray ionization mass spectrometry (ESI-MS), are the mono-hexyl-surfactin C14 ester, mono-hexyl-surfactin C15 ester, mono-2-methoxy-ethyl-surfactin C14 ester,di-hexyl-surfactin C14 ester,di-hexyl-surfactin ester C15,di-2-methoxy-ethyl-surfactin ester C14,di-2-methoxy-ethyl-surfactin ester C15,di-6-hydoxyl-hexyl-surfactin C14 ester and,di-6-hydoxyl-hexyl-surfactin C15 ester. The reaction conditions for esterification were optimized and the dependence of yields on different alcohols and catalysts were discussed. This study shows that esterification is one of the most efficient ways of chemical modification for surfactin and it can be used to prepare more derivatives to meet the needs of study in biological and interfacial activities.Keywords:Keywords: surfactin;esterification;derivatives;lipopeptide;carboxyl group
研究领域:
微生物学
·
生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CARBOHYDRATE POLYMERS
·
2016
·
IF 4.219
Qing Chen,Haojie Yu,Li Wang,Zain-ul Abdin,Xinpeng Yang,Junhua Wang,Weidong Zhou,Hongtao Zhang,Xiao Chen
Amylose grafted poly(acrylic acid) (Am- g -PAA) was synthesized by graft copolymerization of amylose with acrylic acid . The structure of Am- g -PAA was confirmed by 1 H NMR and FT-IR spectra. The morphology, crystallinity and thermal properties of amylose and Am- g -PAA were investigated by SEM, XRD and TGA, respectively. The highest degree of substitution (DS) of carboxyl group was 1.96 which was obtained after reacted for 1 h at 60 °C. Acrylic acid to anhydroglucose mole ratio for DS was 19.81. It was found that a large number of carboxyl groups were grafted on the backbone of amylose. It was also found that ammonia adsorption capacity of amylose increased by grafting poly(acrylic acid) on the backbone of amylose.
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MACROMOLECULAR RAPID COMMUNICATIONS
·
2023
·Vol. 44
·期 10
·2200971
·
IF 4.6
Jie Mao,Jing Li,Wang Lin,Faliang Luo
This work describes an easy and effective process for preparing a homogeneous polybutadiene (PB) dielectric elastomer with improved actuated strain by utilizing a photochemical thiol-ene click reaction. The carboxyl groups and various ester groups are used for grafting on the PB. Since the length of the alkyl chains of the ester groups will significantly influence the polarities of the carbonyl groups and hydrogen bonding effect, the influence of polarity and hydrogen bonding effect on the dielectric properties and mechanical properties of the modified polybutadienes is carefully discussed. Very interestingly, it is found that the increment of dielectric constant of PB modified by carboxyl groups is the lowest one compared to other modified PBs with the ester groups. Meanwhile, the modified PBs with the ester groups could achieve pretty low dielectric loss factor, and finally, a high dielectric constant (3.6), low dielectric loss factor (0.0005), and large actuated strain (≈25%) of the modified polybutadienes could be achieved by the modified PBs with butyl acrylate groups. This work provides a simple and effective method for the designing and synthesizing of a homogeneous high electromechanical performance dielectric elastomer with high dielectric constant and low dielectric loss.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
OPTICAL MATERIALS
·
2025
·
IF 4.2
Zhenchao Gu,Yu Sun,Li Zhang,Mengyang Lv,Lirong Chen
Carboxylated dyes are regarded as the most effective sensitizers for TiO 2 owing to their propensity to establish more stable ester bonds with the TiO 2 surface. Despite this advantage, the prevailing sensitization protocols lack well-defined guidelines, leading to suboptimal photocatalytic performance. As typical carboxylated dyes, tetracarboxyphenyl porphyrin and tetracarboxyzinc phthalocyanine were synthesized and anchored on TiO 2 under different conditions to investigate the regularities in the sensitization conditions of carboxylated dye-sensitized TiO 2 . Significant differences in the morphology of these catalysts can be observed under different sensitization conditions. Solvents with high dye solubility, low viscosity, and high polarity are deemed more suitable for the dye-sensitized systems. The dye ratio and the duration dictate the amount of anchored dye. Agglomeration of dyes caused by high temperatures or excess dye may seriously damage the performance of the photocatalysts. In summary, among commonly used solvents such as dichloromethane, methanol, ethanol, and DMF, DMF was identified as the optimal solvent for sensitizing TiO 2 with carboxylated dyes. A dye dosage of 1 × 10 -5 mol per gram of TiO 2 was found to be sufficient to achieve uniform surface coverage without causing multilayer adsorption or aggregation. Finally, this study investigated the mechanism of how dye sensitization conditions influence the process, and the principles for selecting sensitization conditions in the future were summarized.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2024
·
IF 8.4
Xuesong Li,Xiaolan Chen,Chun Heng Loh,Kunkun Fu,Linyan Yang
Nanofiltration (NF) membranes are increasingly recognized for their proficiency in monovalent/divalent ion separation, making them highly suitable for application such as water softening and resource recovery. This study introduces an innovative in-situ hydrolysis method to enhance the ion selectivity of thin-film composite nanofiltration (TFC-PA NF) membranes. In this method, the reactive monomer in the oil phase was pre-hydrolyzed by contacting with water, producing a partially hydrolyzed monomer that remained soluble in the oil phase. This in-situ hydrolysis process introduced more carboxylic groups to the membrane. That could lead to a proper enlargement of the pore size, subsequently facilitating the separation of Cl − /SO 4 2− . Additionally, the hydrolysis altered the polarity of the acyl chloride molecule, prompting its accumulation at the oil/water interface and accelerating the polymerization reaction rate. This resulted in a thin and exceptionally smooth PA layer. The resulting membrane exhibited a remarkable Cl − /SO 4 2− separation factor of ∼316 under moderate feed concentration and ∼478 under high feed concentration, while maintaining decent water permeance (14.4 L m −2 h −1 bar −1 ). Moreover, its maintained surface carboxylic group density, combined with ultra-low surface roughness, offered drastically enhanced fouling resistance. Our study illuminates the pathway for a straightforward and scalable method to fabricate highly selective membranes with superior fouling resistance.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
Tian Huang,Yue Ma,Huangjingyi Chen,Meijuan Chen,Ruoxian Jia,Lin Lin,Yimin Fan
In this study, a maleic acid (MA) hydrolysis one-pot method is proposed to prepare carboxylated silk nanofibers (MA-SNFs). The MA concentration, hydrolysis temperature, and processing time were optimized. Combined with high-pressure homogenization, MA-SNFs with a carboxyl content of 0.617±0.019 mmol/g and length of 333±116 nm were obtained with a yield of 54.90±1.98 % at the optimal conditions: 50 wt% of MA concentration, 110 °C of hydrolysis temperature and 120 min of processing time. The morphology, chemical structure, and crystal structure of raw silk fibroin (SF), acid-hydrolyzed silk fibroin and nanofibers were studied. Furthermore, MA was reused several times with a recovery rate of >94 % and maintained almost the same treatment effect. Finally, due to the presence of carboxyl groups, MA-SNF hydrogels were successfully prepared by an acetic coagulation vapor bath which exhibited excellent self-supporting ability and mechanical properties as well as a more sensitive pH response compared with regenerated silk fibroin solution and other non-carboxylated silk nanofibers. The MA-SNF aerogels had the characteristics of light weight, high strength and porous with cross-linked nanostructures.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2019
·Vol. 137
·期 3
·48301
·
IF 2.188
Xin Li,Zhuang Liu,LunYu Zhu,ShanShan Miao,Zheng Fang,LiHuan Zhao,Kai Guo
Welan gum has disadvantages such as poor solubility, low viscosity, and poor crosslinking property, when it is applied in petroleum industry, comparing to guar gum. Two methods for the carboxylic modification of welan gum were developed, carboxyethyl modification and citric acid modification, to improve the solubility in water, viscosity, and crosslinking ability of welan gum in the borax crosslinking system. The solubility time of carboxyethyl modified and citric acid modified welan gum were shortened to 30 and 90 min, respectively. The highest viscosity of citric acid modified product was 49.4 mPa s, the viscosity after crosslinking was raised at least 1.2 times to the highest four times than that before crosslinking. The results indicated three factors affecting the properties of modified products: (1) how many function groups in the modifying agent; (2) the way to connect the function group; and (3) the whole structure of the modifying agent. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137 , 48301.
研究领域:
材料科学
·
石油工程
·
应用化学
✓ 已验证
DOI
高影响因子
Arabian Journal of Chemistry
·
2020
·
IF 4.762
Hang Yu,Jing Wang,Jun-xia Yu,Yi Wang,Ru-an Chi
Adsorption performance and stability of the carboxyl groups modified straws and their extracts of cellulose, lignin, and hemicellulose for Pb 2+ were investigated, and the optimum pH range for Pb 2+ adsorption was determined by considering both the stability and capacity of the modified biosorbents for the first time. Results showed that adsorption capacity and stability of the straws and extracts were both improved significantly after modification. Adsorption capacities of the modified straws and extracts followed the order: modified hemicellulose > modified lignin, modified straw > modified cellulose, while stability of them followed the reverse order. In the optimum pH range from 4.0 to 5.0, modified rape and cotton straw showed better stability than the modified maize straw, and total organic carbon (TOC) values determined from the two modified straws and extracts were lower than 5.0 mg L −1 even after adsorption for 30 days, which reached the drinking water standard in China.
研究领域:
环境科学
·
生物化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2019
·
IF 5.155
Cong Liu,Yanhui Li,Qian Duan
A novel hybrid organic/inorganic magnetic and thermal dual-responsive core-shell green photocatalyst zinc-tetracarboxyl-phthalocyanine- g -Fe 3 O 4 @SiO 2 @TiO 2 - g -poly( N -isopropyl acrylamide) had been prepared. Firstly, Fe 3 O 4 @SiO 2 @TiO 2 (FST) was prepared with core-shell structure, then thermosensitive poly( N -isopropylacrylamide) (PNIPAM) immobilized on the surface of 3-(methacryloxypropyl)-trimethoxysilane (MPS) modified FST by radical polymerization. Below the lower critical solution temperature (LCST), PNIPAM was hydrophilic to ensure them disperse uniformly in aqueous solution, and above LCST, PNIPAM became hydrophobic to accelerate the separation of FST from water. Secondly, zinc-tetracarboxyl-phthalocyanine (ZnTcPc) grafted on the surface of FST- g -PNIPAM by ester bonds and sensitized TiO 2 to broaden absorption light range from ultraviolet to visible region to enhance photocatalytic activity. The photocatalytic test revealed that the decomposition rate of Rhodamine B (RhB) came to 91.8% after 60 min with ZnTcPc- g -FST- g -PNIPAM under visible light. When exposed under sun light, the degradation efficiency reached to 96.9%. It meant ZnTcPc- g -FST- g -PNIPAM was more suitable for organic pollutant degradation in nature. In addition, ZnTcPc- g -FST- g -PNIPAM performed efficient synergistic effect of thermal (>LCST) and magnetic responded recovery for reusing. And the degradation rate of RhB under recyclable photocatalyst was reduced 9.6% after 4 cycles. Above all, ZnTcPc- g -FST- g -PNIPAM would be an efficient photocatalyst with magnetic and thermal dual-responsive recovery used in water treatment.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2018
·Vol. 42
·期 8
·6274-6282
·
IF 3.201
Shuang Chen,Hao Wu,Jing-han Hua,Jing-wen Yang,Hong-bin Zhang,Xue-qin Hu
Dextran is a polysaccharide with a high medicinal value. Thus, the chemical modifications of dextran, and the structural and physicochemical properties of its derivatives should be given focus. Dextran (Mw 5000 Da to 7500 Da) can complex with iron. In this study, dextran (Mw 5400 Da) was modified at different pH levels (8–14) by using NaOH and NaClO/NaBr. The carboxyl groups of the modified dextran were determined using infrared spectroscopy, and the carboxyl contents were compared. The results of high-performance liquid chromatography indicated that dextran was degraded during the modification. The crystallization and the structure of the carboxyl-modified dextran were investigated using X-ray diffraction, nuclear magnetic resonance, and quadrupole time-of-flight mass spectrometry. The physicochemical properties, i.e., solubility, and granule morphology, of the carboxyl-modified dextran were carefully characterized and compared. This work provides a theoretical foundation for the accurate selection of carboxyl-modified dextran and the development of a novel strategy for the preparation of metal complexes.
研究领域:
生物化学
·
材料科学
✓ 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）