POLYMER DEGRADATION AND STABILITY
·
2022
·
IF 5.204
Xinming Ye,Yu Feng,Panpan Tian,Zhimao Li,Yingchun Li,Wensheng Wang,Jie Li,Liang Qiao,Kun Wang,Wenchao Zhang,Ye-Tang Pan,Rongjie Yang
Despite remarkable advances in developing flame retardants and smoke suppressants for epoxy resin (EP), engineering nitrogen-containing polyhedral oligomeric silsesquioxane (N-POSS) to impart superior fire safety properties to EP has remained an intractable challenge. In this work, two nitrogen-containing polyhedral oligomeric silsesquioxanes (N-POSSs), namely, aminoethyl-aminopropyl-hepta-phenyl polyhedral oligomeric silsesquioxane (AEAP-POSS) and aminopropyl-hepta-phenyl polyhedral oligomeric silsesquioxane (AP-POSS), were synthesized through the “corner-capping” reaction. The molecular structures of N-POSSs were fully characterized by FTIR, 1 H NMR, 29 Si NMR and MALDI-TOF MS, and the synthesized AEAP-POSS and AP-POSS were introduced into EP to solve the shortcomings of flammability. TGA results showed that the incorporation of 4 wt% N-POSS nanoparticles distinctly improved the char residue at 800 °C, which significantly enhanced the thermal stability of the EP composites. When 4 wt% of AP-POSS was introduced into EP, reductions in the peak of heat release rate (p-HRR), fire growth index (FGI), peak of smoke production rate (p-SPR), and the peak of CO production rate (p-COP) reached to 60.6%, 70.2%, 52.3% and 60.4%, respectively. Subsequently, TG-FTIR and XPS were utilized to investigate the flame retardancy and smoke suppression mechanism. Our work presented a considerable advancement for the facile fabrication of flame retardants based on nitrogen-containing polyhedral oligomeric silsesquioxane compounds.
研究领域:
材料科学
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化学工程
·
高分子科学
·
消防安全工程
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DOI
高影响因子
JOURNAL OF SEPARATION SCIENCE
·
2022
·Vol. 45
·期 9
·1580-1589
·
IF 3.614
Mengyao Fu,Baichun Wang,Linhua Yi,Xueting Jin,Yinghua Yan,Chuan-Fan Ding
In this work, a novel porous bifunctionalized composite material was synthesized via a simple method. Gold nanoparticles are uniformly dispersed on the surface of the biomimetic honeycomb chitosan membrane through the interaction between amino and Au, and then cysteine and glutathione are successfully grafted onto the surface of the Au by the Au-S bond. The modification of cysteine and glutathione makes this bifunctionalized composite material have significant advantages of superhydrophilicity and small steric hindrance simultaneously. This material manifests excellent property in glycopeptides enrichment, with high selectivity (1:5000), low detection limit (0.1 fmol·μL –1 ), high recovery rate (99.4 ± 0.5%), and good repeatability. In addition, with the help of nano-flow liquid chromatography tandem mass spectrometry, this composite achieved excellent performance in efficiently enriching glycopeptides in the serum of healthy people and nasopharyngeal carcinoma's disease patient. More excitingly, further gene ontology analysis of molecular function and biological process indicated that 41 original glycoproteins of the identified glycopeptides from serum of nasopharyngeal carcinoma's disease patient significantly partake in numerous cancer-associated events, including protease binding, calcium ion binding, enzyme binding, extracellular matrix organization, cellular response to tumor necrosis factor, and inflammatory response.
研究领域:
生物材料
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癌症研究
·
分析化学
·
生物信息学
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DOI
高影响因子
ENERGY & FUELS
·
2018
·
IF 3.024
Qian Zhao,Wenbo Zhao,Muyuan Chai,Ling Chen,Yang Wang,Qingming Jia,Yuan Chen
As SO2 removal via traditional aqueous amine scrubbing requires large amounts of energy for absorbent regeneration, phase-change absorption was considered to be a promising alternative, as regeneration of only the SO2-rich phase is needed. The SO2-lean phase can be directly reused, thus greatly reducing energy requirements. We herein investigated the phase-change absorption behavior of N,N,N′,N′-tetramethyl-p-phenylenediamine (TPD) in organic solvents. In general, the TPD absorption rate in organic solvents followed the order: dimethylformamide > diethylene glycol dimethyl ether > propylene carbonate > butanol, which is related to their Henry’s constant. Our results indicated that TPD reacted with SO2 to form the charge-transfer complex TPD·SO2, which was further converted into TPD·2SO2 upon increasing the absorption time. Furthermore, the addition of H2O promoted the formation of TPD·2SO2, but it exhibited a negative effect on the absorption rate. Moreover, in the presence of O2 and H2O, TPD·SO2 in solution was converted slowly into [H2TPD][HSO4]2. TPD·SO2 decomposed into TPD and SO2 at ∼100 °C and exhibited a relatively stable recyclability for SO2 absorption. At last, TPD·SO2 was used as a surrogate of SO2 to synthesize sulfonamide; its activity was higher than that of a reported complex of triethylenediamine and SO2.
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产品关联
DOI
高影响因子
SOLID STATE IONICS
·
2018
·
IF 2.751
Mingzhao Xu,Mingyue Gang,Li Cao,Xueyi He,Yimeng Song,Zhongyi Jiang,Hong Wu,Yanlei Su
Anion-exchange membranes (AEM) are prepared from chloromethylated poly(ether ether ketone) (CMPEEK), which is quaternized by N , N , N ′, N ′-tetramethyl-1,4-phenylenediamine (TMPD) and 1-methylimidazole using a two-step method. TMPD can not only improve the mechanical properties but also provide more ion exchange groups and improve the availability of quaternary ammonium (QA) groups. By varying the amount of TMPD in the membrane casting solution , the comprehensive properties of the membranes are optimized and intensified. The anion conductivity is increased from 0.028 S cm −1 of the imidazolium functionalized poly (ether ether ketone) (ImPEEK) control membrane to 0.042 S cm −1 of the TMPD/ImPEEK membrane with a TMPD content of 5 wt%. Meanwhile, a 31.5% increase in ultimate tensile strength and a 27.8% increase in Young's modulus of the TMPD/ImPEEK membrane are achieved. This study exploited a facile approach to solving the trade-off relation between anion conductivity and mechanical properties.
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产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2023
·
IF 9.9
Fangbao Fu,Dongjie Yang,Bowei Zhao,Yukang Fan,Weifeng Liu,Hongming Lou,Xueqing Qiu
Heteroatom-doped porous carbon materials show promise for use as supercapacitor electrodes, but the tradeoff between surface area and the heteroatom dopant levels limits the supercapacitive performance. Here, we modulated the pore structure and surface dopants of N, S co-doped hierarchical porous lignin-derived carbon (NS-HPLC-K) via self-assembly assisted template-coupled activation. The ingenious assembly of lignin micelles and sulfomethylated melamine into a magnesium carbonate basic template greatly promoted the KOH activation process, which endowed the NS-HPLC-K with uniform distributions of activated N/S dopants and highly accessible nanosized pores. The optimized NS-HPLC-K exhibited a three-dimensional hierarchically porous architecture composed of wrinkled nanosheets and a high specific surface area of 2538.3 ± 9.5 m 2 /g with a rational N content of 3.19 ± 0.01 at.%, which boosted the electrical double-layer capacitance and pseudocapacitance. Consequently, the NS-HPLC-K supercapacitor electrode delivered a superior gravimetric capacitance of 393 F/g at 0.5 A/g. Furthermore, the assembled coin-type supercapacitor showed good energy-power characteristics and cycling stability. This work provides a novel idea for designing eco-friendly porous carbons for use in advanced supercapacitors.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2010
·
IF 3.167
Tao Xu,Meihua Xin,Mingchun Li,Huili Huang,Shengquan Zhou
O -Methyl free N , N , N -trimethyl chitosan (TMC) was synthesized by treating chitosan with formic acid and formaldehyde firstly, followed by methylation with CH 3 I. TMC was further carboxymethylated by monochloroacetic acid to obtain N , N , N -trimethyl- O -carboxymethyl chitosan (TMCMC). The products were characterized by FTIR, 1 H NMR, EA and TGA. Their antibacterial activity was investigated against Staphylococcus aureus and Escherichia coli . The antibacterial activity of TMC decreased as the degree of substitution increased at pH 5.5. But the structure activity relationship was reversed at pH 7.2. TMCMC acted weaker than TMC, and its activity decreased as the degree of carboxymethylation increased. The experimental results showed that the activity of N , N , N -trimethyl amino group was weaker than other non-quaternized amino groups, and carboxymethylation didnot enhance the antibacterial activity directly.
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Liju Bai,Shijian Lu,Qizheng Zhao,Linlin Chen,Yingjie Jiang,Chunxiao Jia,Siming Chen
Non-aqueous biphasic solvents, which combine the advantages of a non-aqueous absorbent and biphasic absorbent, have attracted increasing attention for CO 2 capture because of their great potential to reduce the energy consumption. This study proposed a non-aqueous N -ethylethanolamine (EMEA)/ N , N -diethylethanolamine (DEEA)-based liquid–liquid biphasic absorbent with p -xylene (PX) to replace 45–65 % of DEEA. The biphasic absorbent comprising 30 wt% EMEA + 5 wt% DEEA + 65 wt% PX (30E5D65P) had the best phase-change behaviour. In this absorbent, 98.8 % of the absorbed CO 2 was in the lower phase of the solvent, with a volume percentage of 35.1 %. This absorbent also showed the best CO 2 -desorption performance, with almost double the CO 2 -desorption amount and maximum CO 2 -desorption rate compared with those achieved using the 30 wt% EMEA + 70 wt% DEEA (30E70D) non-aqueous absorbent. The regeneration energy of 30E5D65P was 1.71 GJ∙t −1 CO 2 , which was reduced by 31 % and 55 % compared with that of the non-aqueous 30E70D absorbent and the aqueous 30 wt% monoethanolamine absorbent, respectively. 13 C NMR analysis and quantum chemical calculations showed that carbamate and PX have a better separation effect than that of EMEA and DEEA, owing to the presence of both polarity and hydrogen bonding. PX with low polarity was beneficial for the separation of carbamate. The carbamate interacted with (protonated) EMEA, (protonated) DEEA and carbamic acid through hydrogen bonds, resulting in the appearance of these components in the lower phase. The carbamate had no hydrogen bond self-aggregation, which may be the reason why there was no crystal precipitation.
研究领域:
化学工程
·
环境科学
·
能源技术
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DOI
高影响因子
Nanoscale
·
2017
·Vol. 9
·期 47
·18940-18950
·
IF 7.367
Huabin Chen,Wenxia Liu,Bin Hu,Zhuozhuo Qin,Hong Liu
The development of full-spectrum photocatalysts active in the near-infrared (NIR) region has gained increasing attention in the photodegradation of organic pollutants. Herein, we designed a full-spectrum photocatalyst with strong NIR photoactivity based on the synergy of Er3+-doped ZnO-CuO-ZnAl2O4 multi-phase oxides (Er3+-doped Zn/Cu/Al-MPO) via the formation of n–p–n double heterojunctions. The photocatalyst was prepared by synthesizing nanosheets of a Zn/Cu/Al/Er hydrotalcite-like compound (Zn/Cu/Al/Er-HLC) with a co-precipitation method followed by calcination of the nanosheets at 800 °C. The as-prepared Er3+-doped Zn/Cu/Al-MPO inherits the nanosheet morphology of Zn/Cu/Al/Er-HLC, and displays over-doubled photoactivity in the entire ultraviolet (UV), visible and NIR regions compared to undoped Zn/Cu/Al-MPO. The excellent photocatalytic activity of Er3+-doped Zn/Cu/Al-MPO, especially its strong NIR photoactivity, is ascribed to its Er3+-doped CuO-involved multi-crystalline phase heterostructure, i.e., n–p–n double heterojunctions, which does not only offer an enhanced NIR absorption but also promotes the separation of photogenerated charge carriers. Importantly, the synergy of all the parts of the n–p–n double heterojuctions plays an important role in interface band structure regulation for the enhancement of the photocatalytic properties of Er3+-doped Zn/Cu/Al-MPO. This work has demonstrated the feasibility of utilizing hydrotalcite-like precursors in the design of full-spectrum photocatalysts active in the NIR region.
研究领域:
材料科学
·
环境科学
·
化学工程
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DOI
高影响因子
MACROMOLECULAR MATERIALS AND ENGINEERING
·
2019
·Vol. 304
·期 11
·1900309
·
IF 3.038
Changzhuang Bai,Qiuhua Huang,Xiao Zhang,Xiaopeng Xiong
Tough hydrogels receive continuous attention because of their promising applications in many fields. Herein, tough hydrogels of poly ( N , N -dimethylacrylamide) (PDMAA)/alginate (SA) are prepared, with interpenetrating network (IPN) and of PDMAA/chitosan (CS) with semi-IPN microstructure, respectively. The toughening of the hydrogel by incorporating natural polymers is studied by compressing tests and dynamic mechanical analyses. Moreover, cyclic load–unload compressing of the two types of hydrogels are performed at low strains and under relatively high strains, in order to compare their strength and anti-fatigue properties. The results indicate that the mechanical strength can be markedly improved upon addition of the natural polymers, and the IPN hydrogel of PDMAA/SA reveals much higher mechanical performances but is less stable. However, the semi-IPN hydrogel of PDMAA/CS displays excellent anti-fatigue stability, but with relatively low strength. Swelling tests, scanning electron microscopy, and Fourier transform infrared spectroscopy are carried out to study the microstructures of the hydrogels, which are carefully analyzed to understand the difference in mechanical performances of those hydrogels. The results suggest that the presence of sacrificial unit and higher chain density in the IPN are helpful for toughening hydrogels, while the semi-IPN network is beneficial to improve the energy dissipation efficiency.
研究领域:
材料科学
·
高分子科学
·
生物医学工程
·
软材料
·
聚合物力学性能
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DOI
高影响因子
DRUG DEVELOPMENT AND INDUSTRIAL PHARMACY
·
2018
·
IF 1.883
Jie Liao,Xiaoting Ren,Bowen Yang,Hou Li,Yuexin Zhang,Zongning Yin
Lumbrokinase (LK) has strong fibrinolytic and thrombolytic activities, but it has a short half-life, can be easily inactivated, and may cause hemorrhage as a side effect. This study develops a potential thrombolytic therapy by fabricating N,N,N-Trimethyl Chitosan (TMC) nanoparticles modified with the cyclic Arg-Gly-Asp-Phe-Lys peptide (c-RGD) and loaded with LK (i.e. c-RGD-LK-NPs). The binding of c-RGD to platelet membrane GPIIb/IIIa receptors is expected to enable targeted delivery of the c-RGD-conjugated TMC to the thrombus. The synthesized c-RGD-LK-NPs had a mean particle size of 232.0 nm, zeta potential of 19.8 mV, entrapment efficiency of 52.7% ± 2.5%, and loading efficiency of 17.4% ± 0.65%. Transmission electron microscopy showed that they were generally spherical. The c-RGD-LK-NPs gave a cumulative in vitro LK release of 80.6% over 8 h, and the activity of LK was close to 80%, indicating that the nanoparticles protected the activity of LK. In vitro blood clot lysis assays were carried out and in vivo thrombolysis effect was tested in Sprague-Dawley rats carotid artery thrombus model. In all cases, the c-RGD-LK-NPs showed superior performance compared with the free LK and the unmodified TMC nanoparticles loaded with LK. The c-RGD-LK-NPs reagent is expected to be potentially useful in treating thromboembolic diseases.
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产品关联
DOI
PubMed
高影响因子
MACROMOLECULES
·
2013
·
IF 5.521
Meihan Dan,Yang Su,Xin Xiao,Shentong Li,Wangqing Zhang
A new family of the thermo-responsive polymers based on poly[N-(4-vinylbenzyl)-N,N-dialkylamine] with the pendent amine group as well as the doubly thermo-responsive triblock copolymer were synthesized by reversible addition–fragmentation chain transfer (RAFT) polymerization. These polymers showed the lower critical solution temperature (LCST) and/or the upper critical solution temperature (UCST) in alcohol and in the alcohol/water mixture. The polymer molecular weight, the polymer concentration, the cosolvent/nonsolvent and the deuterated solvent affecting the LCST and/or UCST were investigated, and their great influence on the LCST/UCST was demonstrated. The origin of the phase transition of poly[N-(4-vinylbenzyl)-N,N-dialkylamine] at LCST upon heating was investigated and the possible reason was proposed. The doubly thermo-responsive triblock copolymer of PVMA53-b-PVEA108-b-PVMA53 underwent phase transition at two LCST temperatures. The PVEA108 block underwent the initial phase transition at the first LCST of 32.5 °C to form core–corona micelles, and then the subsequent phase transition of the PVMA53 block took place at the second LCST of 54.5 °C to produce corona-collapsed micelles. The proposed polymers based on poly[N-(4-vinylbenzyl)-N,N-dialkylamine] are anticipated to broaden the thermo-responsive polymer range and will be useful in polymer science.
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产品关联
DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2015
·
IF 4.074
Hongqi Ren,Shuai Liu,Jixiang Yang,Xian Zhang,Hao Zhou,Jiatong Chen,Tianying Guo
A novel non-viral gene carrier based on N , N , N -trimethylchitosan (TMC) has been fabricated. First, well-defined copolymer P (PEGMA- co -DMAEMA) was synthesized through reversible addition fragmentation chain transfer (RAFT) polymerization of poly(ethylene glycol) methyl ether methacrylate (PEGMA) and N , N -(2-dimethylamino)ethyl methacrylamide (DMAEMA). Then allyl group grafting N , N , N -trimethylchitosan (Allyl-TMC) was synthesized via the reaction between allyl bromide and hydroxyl of TMC. Finally, P (PEGMA- co -DMAEMA) and folate were ordinally grafted onto Allyl-TMC to obtain TMC- g - P (PEGMA- co -DMAEMA)-FA. In comparison with pristine chitosan, TMC- g - P (PEGMA- co -DMAEMA)-FA has achieved both better water solubility and stronger pDNA packaging ability, which can contribute to improving gene transfection. Gene delivery efficiency of a series of TMC based functional polymers with different chitosan molecular weights has been tested. The results show that 20k-TMC- g - P (PEGMA- co -DMAEMA)-FA/pDNA complex at the weight ratio of 20 achieve the highest transfection efficiency in 293 T cells. This work presents a new strategy to modify chitosan efficiently as gene carrier material.
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产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）