RSC Advances
·
2017
·Vol. 7
·期 12
·6972-6980
·
IF 3.108
Xiaohui Liu,Qian Zhu,Qiuyan Zhang,Yanguang Zhang,Chen Ding
Over the past few years, ionic liquids (ILs) have been widely reported as reaction media for reverse atom transfer radical polymerization (ATRP). In particular, almost all the ILs with the structure [Hmim][RCOO] (R represents an alkyl group) have been used as ligands for a reverse ATRP system. However, the facile, simple and low-cost ILs, 1-alkyl-3-methylimidazole chloride ([Rmim][Cl]), have rarely been employed as ligands for reverse ATRP. In this article, a [Rmim][Cl] was successfully employed as a ligand for the reverse ATRP of methyl methacrylate with Fe(III) as catalyst and 2,2′-azobisisobutyronitrile as initiator. The key to success is to adjust the FeCl3/[Rmim][Cl] molar ratio value to 1 : 1. The results indicated that the polymerization with [Rmim][Cl] as a ligand proceeded in a controlled/“living” fashion, as evidenced by the first-order kinetic plot, low polydispersity index values, and increase in polymer molecular weight with monomer conversion. The effects of various experimental parameters, including different catalysts, reaction temperatures, solvents, and molar ratios of FeCl3/[Rmim][Cl], on the polymerization were investigated in detail. Furthermore, 1H NMR and gel permeation chromatography analyses confirmed the halogen-containing chain-end functionality of the resultant polymer.
研究领域:
高分子化学
·
有机合成
·
催化化学
·
功能材料
·
可控自由基聚合
✓ 已验证
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2016
·
IF 5.557
Jiayou Liao,Zhi Wang,Ming Wang,Chengyun Gao,Song Zhao,Jixiao Wang,Shichang Wang
An ion-exchange material – Poly(diallyldimethylammonium carbonate) (PDDACA) containing mobile carbonate has been prepared and it has been blended in a fixed carrier membrane material – polyvinylamine (PVAm) containing abundant amine-group to adjust the carrier microenvironment of the fixed carrier membrane. It makes the mobile carrier cruise around the fixed carrier. On one hand, the CO 2 can be transported continuously in the swing area of fixed carrier through the mobile carriers, the passivity of fixed carrier can be overcome and the utilization efficiency of fixed carrier can be enhanced. On the other hand, a loose and low crystalline system will be obtained by blending two polymers, the number of effective mobile carrier will be increased with mobile carriers unlocking from the crystalline area, and the loose and low crystalline system will provide a good environment for the movement of mobile carriers. These are conducive to enhance the performance of blend membrane in comparision with single polymer membrane. The CO 2 permeance and CO 2 /N 2 selectivity of PVAm-PDDACA membrane, which concurrently contains fixed amine carriers and movable carbonate carriers, can reach 909 GPU and 102 at 0.11 MPa, respectively. The performance of PVAm-PDDACA membrane is enhanced obviously in comparision with PVAm membrane and PDDACA membrane.
研究领域:
膜科学与技术
·
气体分离
·
高分子材料
·
化学工程
·
环境化工
·
能源材料
·
功能材料
✓ 已验证
DOI
高影响因子
CHROMATOGRAPHIA
·
2018
·Vol. 82
·期 3
·683-693
·
IF 1.401
Shen Chen,Wu Tong,Zang Xiaohuan
In this work, a zeolitic imidazolate framework-based graphene oxide composite (ZIF-8@GO) was prepared and used as the adsorbent in hollow fiber stir bar sorptive extraction. The stir bar was constructed of a small section of hollow fiber filled with 5 mg ZIF-8@GO and a thin stainless wire of 1.5 cm long in its lumen, and used to extract the trace levels of phthalate esters from children’s food samples prior to gas chromatography–mass spectrometric detection. The ZIF-8@GO showed a high adsorption efficiency for the compounds containing aromatic rings. The main experimental parameters that can impact the extraction efficiency including extraction temperature, extraction time, stirring rate, sample salinity, and desorption conditions were investigated. Under the optimized conditions, the limits of detection (LODs) for the five phthalate esters (diethyl phthalate, dipropyl phthalate, diisobutyl phthalate, butylbenzyl phthalate, and di(2-ethylhexyl) phthalate) were 0.15–0.6 µg L −1 for CiCi beverage and pear juice samples, and 0.75–2.2 µg kg −1 for jam samples. The limits of quantitation (LOQs) were 0.5–2.0 µg L −1 for CiCi beverage and pear juice samples, and 2.5–7.5 µg kg −1 for jam samples. Wide linear ranges of 0.5–500.0 µg L −1 and 2.5–2000 µg kg −1 were obtained for CiCi beverage, pear juice samples and jam samples, respectively, with good repeatability (RSD < 11%) and high method recoveries (72%–100%). The lifetime test results showed that the ZIF-8@GO-based hollow fiber stir bar can be reused for 120 extraction cycles without a significant loss of extraction efficiency, indicating its high durability and stability. The established method was applied successfully for the determination of the phthalate esters (PAEs) in children’s food samples. Graphical abstract
研究领域:
分析化学
·
食品安全
·
环境毒理学
·
暴露科学
·
食品化学
·
污染物检测
✓ 已验证
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2023
·Vol. 11
·期 3
·110269
·
IF 7.7
Jinghua Li,Haofeng Zhu,Dandi Fang,Xusheng Huang,Chaoqun Zhang,Ying Luo
Although the recycling and reuse of polyurethane foam (PUF) is a promising route to deal with this type of waste commodity polymer, highly efficient and green processing protocols are a great challenge due to their stable crosslink structure. In this study, a strategy of urethane exchange reactions was proposed to transform commercial rigid PUF into PUF sheets. The process was composed of the pulverization of the foam, the pretreatment method and the hot pressing. The effects of the pretreatment method on the structure and properties of the recycled commercial PUF were studied. The results show that the ball milling pretreatment method can effectively pulverize the commercial PUF into powder of 74.5 µm and a specific surface area as high as 2991.0 m 2 /kg, which can promote the urethane exchange reaction in close contact with the catalyst. The recycle method of ball milling pretreatment makes the crosslink density and tensile strength of the PUF sheets reach 2236.8 mol/m 3 and 32.6 MPa, which means an increase of 9.9 times and 3.3 times, respectively, compared to the method of other pretreatment. Moreover, PUF sheets can still maintain 71.5% of the tensile strength after two cycles of recycling, indicating the potential of this recycling method for PUF. This simple and efficient method enhances the sustainability of rigid PUF utilization and shows the enormous potential for value-added recycling of thermosets .
研究领域:
高分子材料科学
·
环境科学与工程
·
绿色化学
·
资源循环利用
·
材料再生
·
可持续材料技术
·
功能高分子
✓ 已验证
DOI
高影响因子
THERMOCHIMICA ACTA
·
2016
·
IF 1.938
Lipeng Wang,Fucheng Zhang,Yongping Bai,Liping Ding
The kinetic of non-isothermal crystallization of Poly (ethylene terephthalate-co-sodium-5-sulfo- iso -phthalate) (PETI) was investigated using differential scanning calorimetry (DSC). Various macrokinetic models namely the Avrami, Tobin, Ozawa, and Ziabicki were used to describe the non-isothermal crystallization process of PETI. Both of the Avrami crystallization rate constant and the Tobin crystallization rate constant were observed to increase with increasing cooling rate. The Avrami model is better than the Tobin model to describe the non-isothermal crystallization process of PETI. The Ozawa crystallization rate K O was found to decrease with increasing cooling rate, while Ziabicki’s kinetic crystallizability parameter G Z was found to increase with increasing cooling rate. The effective energy barrier △E for non-isothermal crystallization process of PETI, analyzed based on the differential iso-conversional method of Friedman, was found to be an increasing function of the relative crystallinity.
研究领域:
高分子化学
·
材料科学
·
物理化学
·
热分析
·
聚合物结晶
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2018
·
IF 5.091
Siyuan Dong,Yingqi Jia,Xiaozhi Xu,Jianeng Luo,Jingbin Han,Xiaoli Sun
Poly(ethylene terephthalate) (PET) generally suffers from low crystallization rate and long molding duration, which as a result limit its application as engineering plastics. To overcome these drawbacks, series of PET/layered double hydroxide (LDH) nanocomposites were prepared by a solution blending process. The effect of metal composition (MgAl and CaAl) and organo-modification (stearic acid intercalated) for LDH fillers on the crystallization behavior of the nanocomposites was investigated. It was revealed that, compared with PET/CaAl-LDH, the PET/MgAl-LDH nanocomposite exhibits a higher crystallization temperature and faster crystallization rate, which is associated with the superior nucleation ability of MgAl-LDH. The nucleation mechanism of PET induced by LDHs was explored by means of Avrami equation and theory of Hoffman-Lauritzen, pointing out that the incorporation of LDHs reduce the free energy of nucleation and the fold surface free energy of PET. In order to improve the compatibility between LDH and PET, stearic acid (SA) intercalated MgAl-LDH was prepared and filled into PET matrix. The resultant PET/MgAl-LDH-SA shows a further enhanced crystallization temperature and accelerated crystallization rate, in comparison with PET/MgAl-LDH nanocomposites. In addition, the thermal stability, gas barrier and mechanical properties of PET/LDH composites were improved upon incorporation of LDH fillers.
研究领域:
高分子科学
·
材料化学
·
纳米复合材料
·
结晶动力学
·
聚合物物理
·
功能材料
·
工程塑料
✓ 已验证
DOI
高影响因子
Energy Technology
·
2019
·Vol. 7
·期 4
·1800981
·
IF 3.163
Bangwei Deng,Hao Wang,Xiang Li,Yan Ding,Daming Sun,Jun Ma,Mianzhong Chen,Tao Chen,Feng Gao,Meizhen Qu,Gongchang Peng
Tris(trimethylsilyl)phosphite (TMSPi) has been reported to be an excellent electrolyte additive. However, scarce reports exist on the effect of the charge cutoff potential on the cyclic stability using high-performance LiNi 0.6 Co 0.2 Mn 0.2 O 2 (NCM622)–mesocarbon microbead (MCMB) full cells. Herein, a high-loading and repeatable NCM622–MCMB coin-type full cell is successfully prepared, and the role of TMSPi on such a full cell at charge cutoff potentials of 4.25 and 4.45 V is studied. Theoretical calculations and detailed analyses reveal that it is oxidized in the first charging process due to its unsaturated P—O bonds, thus forming a stable P—O—F-rich cathode electrolyte interphase and preventing severe decomposition of the electrolyte over NCM622 during long-term cycling. In addition, the P—O and Si—O bonds of TMSPi both display HF-scavenging ability. Moreover, TMSPi may react directly with the LiPF 6 -based electrolyte to form some intermediate products that can be reduced on the MCMB electrode, thereby modifying the solid electrolyte interphase and improving the stability of MCMB during lithium intercalation.
研究领域:
电化学
·
材料科学
·
能源存储
·
锂离子电池
·
界面化学
·
电极材料
✓ 已验证
DOI
高影响因子
TALANTA
·
2018
·
IF 4.244
Yucan Che,Hongyu Pang,Huiyu Li,Lei Yang,Xinyao Fu,Shiqi Liu,Lan Ding,Juan Hou
Fluorescent carbon quantum dots are emerging as a new class of fluorescent probes due to their unique optical properties . Herein, we presented a simple, one-pot and effective preparation strategy for copper-functionalized carbon quantum dots (Cu-CDs). The Cu-CDs demonstrated excitation-independent emissions, high fluorescent quantum yield (~ 24.4%) and excellent fluorescent stability. The fluorescence of Cu-CDs could be quenched efficiently in the presence of histidine (His) due to the coordination occurring between surface Cu and imidazole side chains of His. Thus, the Cu-CDs could be used as an efficient fluorescent probe for His detection. Under optimal conditions, the fluorescent signals of Cu-CDs decreased linearly with the concentrations of His over a range of 0.1–15 µM. The detection limit was 30 nM. The proposed method provided obvious advantages of rapid response, convenience, simplicity, high selectivity and sensitivity. Moreover, good results also have been obtained for His detection in real biological fluid samples.
研究领域:
材料科学
·
分析化学
·
生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
POLYMER TESTING
·
2022
·
IF 4.931
Yang-he Mo,Hui Wang,Shao-hua Jin,Ke-lin Peng,Zi-ming Yang,Pu-wang Li,Yu Chen
Fast curing hydrogels are highly valuable in the skin care industry. Multi-arm polyethylene glycol (PEG) is a commonly used crosslinking agent for the preparation of fast curing hydrogels. However, the hydrogel preparation using multi-arm PEG crosslinking agents usually requires the end group modifications of reactants, which makes the preparation process complicated and produces hydrogels with low curing rates. In the present study, a fast in situ curing hydrogel, 4-arm-PEG-succinimidyl carbonate/carboxymethyl chitosan (PEG-SC/CMCS), was prepared using 4-arm-PEG-SC as the crosslinking agent and carboxymethyl chitosan (CMCS), a derivative of natural polysaccharide with excellent comprehensive properties, as the framework without any end groups modified. The structure and properties of the prepared hydrogel were characterized by FTIR, XRD, SEM, rheology and swelling kinetics. The effects of reaction conditions on the structure and properties of hydrogel were investigated. The PEG-SC/CMCS hydrogel exhibited pH-sensitive swelling behaviors. Its application potential in skin care products is demonstrated with its excellent sustained-release performance of Vitamin C, a model drug for skin treatment, and high adsorption capacity of heavy metal ions that are easily deposited on skin surface. Our work has provided a new strategy for building multifunctional gel materials for skin care and offered a PEG-SC/CMCS hydrogel with great application potentials.
研究领域:
生物材料
·
高分子化学
·
药剂学
·
皮肤科学
·
组织工程
·
药物递送系统
·
环境毒理学
✓ 已验证
DOI
高影响因子
AAPS PHARMSCITECH
·
2019
·Vol. 20
·期 1
·1-14
·
IF 2.608
Wang Xingqi,Zhang Yong,Huang Jie,Tian Chunling,Xia Mengqiu,Liu Liu,Li Zhengguang,Cao Jiaojiao,Gui Shuangying,Chu Xiaoqin
The purpose of this paper was to investigate the potential of liquid crystalline (LC) gels for ophthalmic delivery, so as to enhance the bioavailability of pilocarpine nitrate (PN). The gels were prepared by a vortex method using phytantriol and water (in the ratio of 73:27 w / w ). Their inner structures were confirmed by crossed polarized light microscopy, small-angle X-ray scattering, attenuated total reflectance-Fourier transform infrared spectrum, and rheology. The in vitro release studies revealed that PN could keep sustained release from the gels over a period of 12 h. The ex vivo apparent permeability coefficient of the gels demonstrated a 3.83-folds ( P < 0.05) increase compared with that of eye drops. The corneal hydration levels of the gel maintained in the normal range of 79.46 ± 2.82%, hinting that the gel could be considered non-damaging and safe to the eyes. Furthermore, in vivo residence time evaluation suggested that a better retention performance of LC gel was observed in rabbit’s eyes compared to eye drops. In vivo ocular irritation study indicated that LC gel was nonirritant and might be suitable for various eye applications. In conclusion, LC gels might represent a potential ophthalmic delivery strategy to overcome the limitations of eye drops.
研究领域:
药剂学
·
药物递送系统
·
眼科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL DE MYCOLOGIE MEDICALE
·
2018
·
IF 1.606
K. Xu,J.L. Wang,M.P. Chu,C. Jia
Objective The aim of this study was to investigate the antibiofilm activity of coumarin against Candida albicans . Methods The efficacy of coumarin against biofilm formation and the mature biofilm of C. albicans was quantified by crystal violet (CV) staining and the 2,3-bis (2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino)carbonyl]-2H-tetrazolium hydroxide (XTT) reduction assay. The effect of coumarin on C. albicans adhesion was assessed on polystyrene plates and by using the cell surface hydrophobicity (CSH) assay. The morphological transition of C. albicans was conducted in two types of hyphae-inducing media at 37 °C. The expression of hypha/biofilm-related genes was evaluated using qRT-PCR analysis. A rescue experiment involving addition of exogenous cyclic adenosine monophosphate (cAMP) was performed to investigate the involvement of cAMP in the yeast-to-hyphae transition. A C. albicans -infected Caenorhabditis elegans model was used to test the anti-virulence efficacy of coumarin. Results Treatment with coumarin strongly affected the capacity of C. albicans to form biofilm and significantly impaired the preformed mature biofilm. The addition of coumarin notably inhibited C. albicans adhesion, CSH, and filamentation . The expression of some adhesion- and hypha-related genes, including HWP1 , HYR1 , ECE1 , and ALS3 , was remarkably down-regulated upon exposure to coumarin. Supplementation with cAMP partly rescued the coumarin-induced defects in hyphal development. Finally, coumarin prolonged survival in C. albicans -infected nematodes. Conclusion Coumarin inhibited C. albicans biofilm, which was associated with attenuated adhesion and hyphal growth.
研究领域:
微生物学
·
药理学
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Revista Brasileira de Farmacognosia-Brazilian Journal of Pharmacognosy
·
2019
·Vol. 29
·期 1
·46-53
·
IF 1.754
Peng Wei,Han Ping,Yu Luyao,Chen Ying,Ye Bingzhu,Qin Luping,Xin Hailiang,Han Ting
The fruits of Xanthium strumarium L., Asteraceae, have been used for various diseases in Chinese folk medicine, including allergic rhinitis, tympanitis, arthritis, ozena etc. The current study was aimed to investigate the therapeutic effects of caffeoylquinic acids from fruits of X. strumarium on allergic rhinitis in animals. The toxicity test indicated that the caffeoylquinic acids have no obvious toxicity. By using HPLC assays combined with reference standards, ten caffeoylquinic acids were identified as the predominant constituents. Anti-allergic activities of the caffeoylquinic acids were evaluated using passive cutaneous anaphylaxis test and Schultz-Dale test; dimethylbenzene induced ear edema test was performed to evaluate its anti-inflammatory effect. Then, the allergic rhinitis model in rats was established to evaluate the therapeutic effects of the caffeoylquinic acids against allergic rhinitis with the following indexes: allergic rhinitis symptom scores, serum levels of pro-inflammatory cytokines, histopathological examination, and histamine release. Our study revealed that the caffeoylquinic acids showed obvious anti-allergic and anti-inflammatory properties, and its treatments were beneficial for ameliorating the nasal symptoms, decreasing pro-inflammatory cytokines, and inhibiting the releases of histamine. Collectively, the caffeoylquinic acids might be utilized as effective and safe disease therapeutic agents for allergic rhinitis.
研究领域:
药理学
·
免疫学
·
过敏
·
植物化学
✓ 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）