Chitosan was modified by conjugating coupling with linolenic acid through the 1-ethyl-3-（3-dimethylami- nopropyyl） carbodiimide （EDC）-mediated reaction. The degree of substitution 1.8% （ i.e. 1.8 linolenic acid g...Chitosan was modified by conjugating coupling with linolenic acid through the 1-ethyl-3-（3-dimethylami- nopropyyl） carbodiimide （EDC）-mediated reaction. The degree of substitution 1.8% （ i.e. 1.8 linolenic acid group per 100 anhydroglucose units） was measured by ^1H NMR. The critical aggregation concentration （CAC） of the self-aggregate of hydrophobically modified chitosan was determined by measuring the fluorescence intensity of the pyrene as a fluorescent probe. The CAC value in phosphate-buffered saline （PBS） solution （pH 7.4） was 5 × 10^-2 mg mL^-1. The average particle size of selfaggregates of hydrophobically modified chitosan in PBS solution （pH7.4） was 210.8 nm with a unimodal size distribution ranging from 100 to 500 nm. Transmission electron microscopy （TEM） study showed that the formation of near spherical shape nanoparticles has enough structural integrity. The loading ability of hydrophibically modified chitosan （LA-chitosan） was investigated by using bovine serum albumin （BSA） as the model. The loading capacity of self-aggregated nanoparticles increases （ 19.85 % ± 0.04 % to 37.57 % ± 0.25 % ） with the concentration of BSA （0.1-0.5 mg mL^-1 ）.展开更多
In this paper, nitrogen-doped hierarchical porous carbon(N-HPC) was prepared from polyaniline(PANI)/silica self-aggregates. H-bonding between N\\H groups in aniline/PANI and \\OH groups in nano silica template led to ...In this paper, nitrogen-doped hierarchical porous carbon(N-HPC) was prepared from polyaniline(PANI)/silica self-aggregates. H-bonding between N\\H groups in aniline/PANI and \\OH groups in nano silica template led to a self-assembly type, which enabled the formation of uniform N-HPC nanoparticles. Silica self-aggregates provided macroporous channels resulted in a decreased diffusion distance. After removing the hard template,the N-HPC had a high surface area(899 m^2·g^(-1)). Owing to two co-existed synergetic energy-storage mechanisms and the hierarchical porous structure, the obtained N-HPC exhibited a high specific capacitance of 218.75 F·g^(-1) at 0.5 A·g^(-1), compared with the nonporous nitrogen-doped carbon(N-C) derived from pure PANI. Moreover, the N-HPC electrode demonstrated excellent cycle life, retaining 99% of its initial specific capacitance after 1000 cycles.展开更多
基金National Natural Science Foundation of China(30370344)Korea Science and Engineering Foundation(19992-220-009-4)supported this study
文摘Chitosan was modified by conjugating coupling with linolenic acid through the 1-ethyl-3-（3-dimethylami- nopropyyl） carbodiimide （EDC）-mediated reaction. The degree of substitution 1.8% （ i.e. 1.8 linolenic acid group per 100 anhydroglucose units） was measured by ^1H NMR. The critical aggregation concentration （CAC） of the self-aggregate of hydrophobically modified chitosan was determined by measuring the fluorescence intensity of the pyrene as a fluorescent probe. The CAC value in phosphate-buffered saline （PBS） solution （pH 7.4） was 5 × 10^-2 mg mL^-1. The average particle size of selfaggregates of hydrophobically modified chitosan in PBS solution （pH7.4） was 210.8 nm with a unimodal size distribution ranging from 100 to 500 nm. Transmission electron microscopy （TEM） study showed that the formation of near spherical shape nanoparticles has enough structural integrity. The loading ability of hydrophibically modified chitosan （LA-chitosan） was investigated by using bovine serum albumin （BSA） as the model. The loading capacity of self-aggregated nanoparticles increases （ 19.85 % ± 0.04 % to 37.57 % ± 0.25 % ） with the concentration of BSA （0.1-0.5 mg mL^-1 ）.
基金Supported by the National Natural Science Foundation of China(21401079,21501069)Fundamental Research Funds for Central Universities(JUSRP51626B)+2 种基金the Natural Science Foundation of Jiangsu Province of China(BK20140158,BK20161128,BK20161166)Natural Science Fund for Colleges and Universities in Jiangsu Province(18KJD430008,17KJD430005,17KJB430032)the Top-notch Academic Programs Project of Jiangsu Higher Education Institutions(PPZY2015B181)
文摘In this paper, nitrogen-doped hierarchical porous carbon(N-HPC) was prepared from polyaniline(PANI)/silica self-aggregates. H-bonding between N\\H groups in aniline/PANI and \\OH groups in nano silica template led to a self-assembly type, which enabled the formation of uniform N-HPC nanoparticles. Silica self-aggregates provided macroporous channels resulted in a decreased diffusion distance. After removing the hard template,the N-HPC had a high surface area(899 m^2·g^(-1)). Owing to two co-existed synergetic energy-storage mechanisms and the hierarchical porous structure, the obtained N-HPC exhibited a high specific capacitance of 218.75 F·g^(-1) at 0.5 A·g^(-1), compared with the nonporous nitrogen-doped carbon(N-C) derived from pure PANI. Moreover, the N-HPC electrode demonstrated excellent cycle life, retaining 99% of its initial specific capacitance after 1000 cycles.
