Journal of Materials Chemistry B
·
2012
·Vol. 1
·期 7
·978-986
·
IF 0
Jintang Zhu,Jianwu Wang,Qianyun Liu,Yahui Liu,Lei Wang,Changcheng He,Huiliang Wang
This work reports a novel method for fabricating anisotropic hydrogels starting from monomers by combining directional freezing and redox polymerization (DFRP), and poly(2-hydroxyethyl methacrylate) (PHEMA) hydrogels with anisotropic porous structures and mechanical properties are obtained. Scanning electron microscopy (SEM) investigations show that the hydrogels have long and wide (up to several tens of micrometers) aligned channels in the direction parallel to the freezing direction, and pores in the perpendicular direction. The sizes of the channels and pores decrease with increasing freezing rate. Tensile, compressive and tearing tests show that the hydrogels (70 wt% water content) show very good mechanical properties, with tensile strength up to 0.44 MPa, compressive strength more than 20 MPa, and fracture energy up to 1000 J m−2. More importantly, the hydrogels exhibit significant anisotropy in their mechanical properties, which are better in the parallel direction. The hydrogels also show different swelling behaviour in comparison with conventional synthetic hydrogels. The anisotropic tough PHEMA hydrogels may find further application.
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HETEROATOM CHEMISTRY
·
2014
·Vol. 26
·期 2
·142-149
·
IF 1.257
Xuefang Shang,Wanli Li,Xiaofang Wei,Huanle Zhang,Zhiyuan Fu,Jinlian Zhang,Xiufang Xu
Two new compounds ( 1 and 2 ) containing 2-sulfydryl-1,3,4-thiodiazole have been synthesized and optimized. They both showed wide antibacterial activity for colon bacillus, Staphylococcus aureus , S. albus , dysentery bacillus and inferior activity for Bacillus subtilis . In addition, their binding properties were evaluated for biologically important anions (F – , Cl – , Br – , I – , AcO – , and H 2 PO 4 – ) by theoretical investigation, UV–vis, fluorescence, and 1 H NMR titration experiments, and they displayed strong binding ability for H 2 PO 4 – without the interference of other anions tested. Especially the binding ability of compound 2 containing anthracene with H 2 PO 4 – was 1000 times stronger than that of compound 1 containing nitrobenzene. Two compounds based on 2-sulfydryl-1,3,4-thiodiazole have both properties of anion recognition and antibacterial activity.
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SYNTHESIS-STUTTGART
·
2014
·Vol. 46
·期 05
·621-628
·
IF 2.443
Shengrong Liao,Chun Qin,Peifen Yao,Jinsheng Li,Xuefeng Zhou,Junfeng Wang,Zhishu Huang,Yonghong Liu
A facile and efficient synthesis of novel seven-membered heterocyclic derivatives containing 3-aminoazepan-2-one backbone is described using 1,4-protected piperazine-2,5-diones and alkynes as starting materials. The reaction may undergo Michael addition, unusual nucleophilic attack to an amide group, and keto–enol tautomerization. The reaction showed different reactivity when using substrates with different protecting groups: it had higher efficiency when using either alkanoyl-protecting group with cesium carbonate as the base, or benzoyl-protecting group with triethylamine as the base, but no reaction when using benzyl or allyl protecting groups with a variety of bases (Et3N, DBU, K2CO3, Cs2CO3, KHCO3, CsHCO3, and KOt-Bu).
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APPLIED CATALYSIS B-ENVIRONMENTAL
·
2015
·
IF 7.435
Dongting Yue,Taiyang Zhang,Miao Kan,Xufang Qian,Yixin Zhao
The sulfur tolerant Mo 3 S 13 2− /BiOBr nanocomposite photocatalysts were facilely fabricated by a hydrothermal method. The characterizations including X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectrometry (EDS), UV–vis diffuse reflection spectroscopy (DRS) and photoluminescence (PL) investigate the structures, elemental composition, morphologies and photocatalytic activities of Mo 3 S 13 2− /BiOBr nanocomposite. The 5.0 wt% Mo 3 S 13 2− /BiOBr composite sample showed highest visible-light-driven photocatalytic activity for decolorization of organic dyes including Rhodamine B (RhB) and sulfure containing methylene blue (MB). The decolorization of RhB was dominated by the direct hole and the generated O 2 − radicals oxidation process . Our 5.0 wt% Mo 3 S 13 2− /BiOBr nanocomposite exhibited comparable photocatalytic activity as the state of art 1 wt% BiOBr/Pt composite for photocatalytic decolorization of RhB. The 5.0 wt% Mo 3 S 13 2− /BiOBr composite possessed better sulfur resistance than 1.0 wt% Pt/BiOBr composite.
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SENSORS AND ACTUATORS B-CHEMICAL
·
2014
·
IF 3.84
Wangyao Zhang,Yang Yang,Fenfen Li,Guosheng Song,Yong Shao,Ruizhuo Ouyang,Lina Xu,Weiwei Li,Yuqing Miao
A simple one-step method was successfully developed to prepare stable nanosized Ni(OH) 2 @Cr(OH) 3 hybrid particles by just adding NaOH to a mix solution containing Ni(NO 3 ) 2 and Cr(NO 3 ) 3 at room temperature. In contrast, under the exact same conditions, flocculent Ni(OH) 2 or Cr(OH) 3 precipitate was obtained after the addition of equivalent NaOH in a solution containing same amount of Ni(NO 3 ) 2 or Cr(NO 3 ) 3 as in the mix solution. The interaction between Ni(II) and Cr(III) ions was believed to make major contribution to the formation of stable Ni(OH) 2 @Cr(OH) 3 nanohybrid without aggregation to large-size particles. The prepared Ni(OH) 2 @Cr(OH) 3 hybrid nanoparticles were well characterized by the scanning electron microscopy (SEM), the transmission electron microscopy (TEM), X-ray diffraction (XRD), and electrochemical measurements with results showing uniform size, smooth surface, good monodispersibility, fast electron transfer rate as well as promising electrocatalytic properties toward glucose (Glu) and cysteine (Cys) oxidation. The presence of a small amount of Cr(OH) 3 in the composite not only improved the stability and monodispersibility of the Ni(OH) 2 @Cr(OH) 3 hybrid particles, decreased their size to nanoscale, but also exerted positive effect to the electrochemical properties of the obtained Ni(OH) 2 based nanomaterials like the electron transfer rate and the electrocatalytic activity. Satisfactory electrocatalytic performances of the Ni(OH) 2 @Cr(OH) 3 nanohybrid toward Glu and Cys oxidations were achieved, respectively, in certain concentration ranges with acceptable detection limits and correlation coefficients, suggesting the potential facilitation of electrocatalysis toward other small molecules by the newly prepared Ni(OH) 2 @Cr(OH) 3 nanohybrid.
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ACS Applied Materials & Interfaces
·
2013
·
IF 5.008
Chaoran Li,Zanyong Zhuang,Feng Huang,Zhicheng Wu,Yangping Hong,Zhang Lin
Treatment of wastewater containing low-concentration yet highly-expensive rare earth elements (REEs) is one of the vital issues in the REEs separation and refining industry. In this work, the interaction and related mechanism between self-supported flowerlike nano-Mg(OH)2 and low-concentration REEs wastewater were investigated. More than 99% REEs were successfully taken up by nano-Mg(OH)2. Further analysis revealed that the REEs could be collected on the surface of Mg(OH)2 as metal hydroxide nanoparticles (<5 nm). An ion-exchange model was proposed as a critical factor for both guaranteeing the reaction speed and maintaining the self-supported structure of the materials. In addition, a method was developed to further separate the immobilized REEs and the residual magnesium hydroxide by varying the solution pH. In a pilot-scale experiment, the REEs from practical wastewater were immobilized effectively at a high flow rate. We anticipate this work can provide a good example for the recycling of valuable REEs in practical industrial applications.
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Journal of Environmental Sciences
·
2013
·
IF 1.773
Liping Hao,Fan Lü,Lei Li,Liming Shao,Pinjing He
To use the selective inhibition method for quantitative analysis of acetate metabolism in methanogenic systems, the responses of microbial communities and metabolic activities, which were involved in anaerobic degradation of acetate, to the addition of methyl fluoride (CH 3 F), 2-bromoethanesulfonate (BES) and hydrogen were investigated in a thermophilic batch experiment. Both the methanogenic inhibitors, i.e., CH 3 F and BES, showed their effectiveness on inhibiting CH 4 production, whereas acetate metabolism other than acetoclastic methanogenesis was stimulated by BES, as reflected by the fluctuated acetate concentration. Syntrophic acetate oxidation was thermodynamically blocked by hydrogen (H 2 ), while H 2 -utilizing reactions as hydrogenotrophic methanogenesis and homoacetogenesis were correspondingly promoted. Results of PCR-DGGE fingerprinting showed that, CH 3 F did not influence the microbial populations significantly. However, the BES and hydrogen notably altered the bacterial community structures and increased the diversity. BES gradually changed the methanogenic community structure by affecting the existence of different populations to different levels, whilst H 2 greatly changed the abundance of different methanogenic populations, and induced growth of new species.
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高影响因子
RSC Advances
·
2015
·Vol. 5
·期 76
·61742-61751
·
IF 3.84
Li Qun Xu,Ning Ning Li,Jiu Cun Chen,Guo Dong Fu,En-Tang Kang
Polymeric quaternary ammonium salts (QAS) have been widely studied for their antimicrobial activities. However, most of them were evaluated and used in solution form, which may limit their other applications, in medical and wound care and surface biofouling prevention. The development of antibacterial agents for use both in solution and in surface biofouling prevention are highly interesting and desirable. In this work, quaternized poly(2-(dimethylamino)ethyl methacrylate)-grafted agarose (Agr-g-QPDMAEMA) copolymers were synthesized via a combination of atom transfer radical polymerization (ATRP) and quaternization of tertiary amine moieties. The resulting Agr-g-QPDMAEMA copolymers can be dissolved in aqueous media at low concentrations to evaluate their antibacterial activity in the solution form. They can also be gelated as hydrogels on substrate surfaces to inhibit bacterial adhesion, biofilm formation and bacterial colonization. The Agr-g-QPDMAEMA copolymer hydrogels can be further fabricated into antibacterial patches to inhibit the bacteria growth on the contaminated surfaces.
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DESIGNED MONOMERS AND POLYMERS
·
2015
·
IF 2.78
Nian Deng,Xufeng Ni,Zhiquan Shen
Poly (diethyl vinylphosphonate-co-2-chloroethyl methacrylate) (P(DEVP-co-CEMA)) copolymers are synthesized by free radical copolymerization initiated by benzoyl peroxide. The reactivity ratios for the free radical copolymerization of CEMA (M1) and DEVP (M2) are r1 = 19.45 and r2 = 0.11, respectively. The desired amphiphilic copolymers with relatively low polydispersity index (PDI) and different DEVP contents are isolated and purified from the reaction mixtures through precipitation fractionation. The structures and molecular characteristics of the obtained products are characterized by 1H NMR, FTIR, and SEC analysis. All of these fractionated copolymers have a unimodal distribution and moderate PDI. The thermal properties of the P(DEVP-co-CEMA) copolymers are investigated by TGA and differential scanning calorimetry (DSC) measurements. Single glass transition temperature (Tg) appears in the DSC profiles differing from the existence of two Tgs in the blend of poly (diethyl vinylphosphonate) and poly (2-chloroethyl methacrylate), which indicates the random structure of the copolymers. The MALDI–ToF mass analysis further reveals that DEVP and CEMA units are randomly distributed in the copolymer chains. The self-assembly behavior of the P(DEVP-co-CEMA) copolymers in aqueous solution is preliminarily investigated.
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POLYMER TESTING
·
2017
·
IF 2.464
Dong Liu,Chengsha Wei,Guanyun Yan,Guangai Sun
A series of well-defined double hydrophilic block copolymers Poly ( N -isopropylacrylamide)- b -poly (2-vinylpyridine) (PNIPAM 38 - b -P2VP 43 ) were synthesized. The ‘schizophrenic’ behavior and the aggregation process of PNIPAM- b -P2VP in response to temperature and pH in dilute aqueous solution were tested via transmittance measurements, dynamic light scattering (DLS), and small-angle neutron scattering (SANS). The results revealed that: i) both PNIPAM-core and P2VP-core micelles can be induced from an intermediate unimers state via the adjustment of temperature and pH; ii) The lower critical solution temperature (LCST) of PNIPAM homopolymers is narrowly in the range of 31–34 °C, while PNIPAM- b -P2VP diblock copolymers at pH = 7 and 2 have broad LCSTs of 25–40 °C and 41-50 °C, respectively; iii) SANS results show that only the PNIPAM- b -P2VP solution at pH = 7 and 50 °C (both blocks are hydrophobic) has a sphere form factor with diameter of about 110 nm.
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CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2017
·
IF 1.174
Weifeng Xu,Guilin Dai,Kewen Tang,Panliang Zhang,Biquan Xiong,Yu Liu
The utilization of liquid–liquid extraction for the separation of 2-phenylbutyric acid (2-PBA) enantiomers was proposed. Factors affecting the extract process were investigated, including organic solvents, β-cyclodextrin derivatives, cyclodextrin concentration, pH and temperature. A model was proposed to describe the separation process based on the homogeneous phase reaction mechanism. Important parameters of this model were determined experimentally. The physical distribution coefficients for molecular and ionic 2-PBA were 0.129 and 7.455, respectively. The equilibrium constants of the complexation reactions were 89.36 and 36.78 L·mol − 1 for (+)− and (−)-2-PBA, respectively. The model was verified by experiments and proved to be an excellent means to optimize the separation system. Through modeling prediction and experiment, the best conditions ( e.g. , pH value of 3.00, extractant concentration of 0.1 mol·L − 1 , temperature of 5.0 °C) were acquired. Under this condition, the maximum enantioselectivity (2.096) was obtained.
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CRYSTENGCOMM
·
2017
·Vol. 19
·期 38
·5780-5786
·
IF 3.474
Kun Ding,Xiao Zhang,Juping Li,Ping Yang,Xin Cheng
Ultrathin α-Co(OH)2 nanosheets (NSs) were hydrothermally synthesized without using surfactants and templates. Interestingly, the ultrathin α-Co(OH)2 NSs evolved from graphene-like NSs to hexagonal nanoplates (NPs) and then transformed into a needle-like Co(CO3)0.5(OH)·0.11H2O phase with increasing reaction temperature and time. The phase and morphology evolution depended strongly on the CO32− ions in the solution. We ruled out the possibility that CO32− originated from the adsorption of CO2 in air and proposed the possible phase transition mechanism from α-Co(OH)2 to Co(CO3)0.5(OH)·0.11H2O, which was due to the decomposition of hexamethylenetetramine driven by dynamics and thermodynamics. The morphology evolution could be regarded as the dissolution–recrystallization–redissolution–recrystallization of α-Co(OH)2. The electrochemical behavior tests demonstrated that the ultrathin α-Co(OH)2 electrode exhibited an excellent specific capacitance of 833.4 F g−1 at 5 A g−1; however, the specific capacitance of the needle-like Co(CO3)0.5(OH)·0.11H2O electrode was 247.2 F g−1 at the same current density. This excellent electrochemical property is attributed to the crystalline phase and ultrathin nature of the materials.
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