Multifunctional membranes based on natural polymers: preparation,characterization and in vitro performance evaluation

The aim of this study was to synthesize new multifunctional biopolymers via esterification of hemp fibres with two reagents: meso‐2,3‐dimercaptosuccinic acid and ethylenediaminetetraacetic acid. The obtained biopolymers were characterized using infrared spectroscopy. The antibacterial activity of the derivative containing ethylenediaminetetraacetic acid moiety was evaluated by assessing the growth inhibition of Pseudomonas aeruginosa in Petri dishes. The results suggest that this biomaterial exhibits an excellent in vitro antibacterial activity. The antioxidant activity of the biopolymer from meso‐2,3‐dimercaptosuccinic acid was tested in rat liver microsomal membranes in the presence of tert‐butylhydroperoxide as free radical source. Results suggest that this material inhibits lipid peroxidation induced by the free radical species. Both derivatives were used to prepare multifunctional membranes that were characterized and tested indicating the maintenance of biopolymer functionalized properties. Moreover, these functionalized biopolymers interact with metal ions due to their chelating functional groups. The absorption capacity for a selected metal ion, Cd(II), was investigated in aqueous solutions at pH = 0.65, 4.1 and 7.0 using optical emission spectroscopy. This study demonstrates that these new materials are very effective in chelating cadmium ions showing maximum efficiency at pH = 7.0. © 2014 Society of Chemical Industry     

Novel chlorhexidine dermal patches,preparation characterization and antimicrobial evaluation

Polymer Bulletin - The purpose of this work is to develop chlorhexidine dermal patches using Eudragit® RL100 as the patch forming polymer. Solvent casting technique was employed in the...     

AM-DMC-SSS-淀粉的合成及性能评价

为进一步改善丙烯酰胺类聚合物在水基钻井液中的应用,采用水溶液聚合法合成了一种新型水溶性AMDMC-SSS-淀粉两性离子聚合物,探索了其合成条件以及在水基钻井液中的应用。结果表明,淀粉接枝聚合物的最佳合成条件为:在一定量淀粉溶液中,引发剂质量分数为0.6%,丙烯酰胺、苯乙烯磺酸钠以及甲基丙烯酰氧乙基三甲基氯化铵质量分数分别为10.3%,10%,7.4%,聚合反应时间为3 h时接枝率最大。在钻井液性能评价实验中,淀粉共聚物加量为0.4%时,淡水钻井液的滤失量由16.5 m L降至7.0 m L,表现出较好的降滤失作用;表观粘度由8.0 m Pa·s增加至32.0 m Pa·s,表现出较强的提粘切能力;页岩回收率由38.5%提高至67.3%,淀粉共聚物具有较好的防塌性;页岩膨胀实验中,淀粉共聚物质量分数为0.5%时,页岩的线膨胀率由22.1%降至11.6%,表现出对页岩膨胀较好的抑制性能。     

AM-DMC-SSS-淀粉的合成及性能评价

为进一步改善丙烯酰胺类聚合物在水基钻井液中的应用,采用水溶液聚合法合成了一种新型水溶性AMDMC-SSS-淀粉两性离子聚合物,探索了其合成条件以及在水基钻井液中的应用。结果表明,淀粉接枝聚合物的最佳合成条件为:在一定量淀粉溶液中,引发剂质量分数为0.6%,丙烯酰胺、苯乙烯磺酸钠以及甲基丙烯酰氧乙基三甲基氯化铵质量分数分别为10.3%,10%,7.4%,聚合反应时间为3 h时接枝率最大。在钻井液性能评价实验中,淀粉共聚物加量为0.4%时,淡水钻井液的滤失量由16.5 m L降至7.0 m L,表现出较好的降滤失作用;表观粘度由8.0 m Pa·s增加至32.0 m Pa·s,表现出较强的提粘切能力;页岩回收率由38.5%提高至67.3%,淀粉共聚物具有较好的防塌性;页岩膨胀实验中,淀粉共聚物质量分数为0.5%时,页岩的线膨胀率由22.1%降至11.6%,表现出对页岩膨胀较好的抑制性能。     

Polycarbonate/silica nanocomposite membranes: Fabrication,characterization, and performance evaluation

Polycarbonate/silica nanocomposite membranes at low silica loading were fabricated by solution blending and solvent evaporation technique. The functionalized silica nanoparticles used were synthesized by co‐condensing hydrolyzed tetraethylorthosilicate with 3‐aminopropyl trimethoxysilane in the sol–gel process. The membranes morphology, composition, surface, structure, thermal and mechanical properties were analyzed by the standard characterization techniques. The gas permeation tests were conducted in four‐channel permeation cells. Field emission scanning electron microscopy results reveal that membranes above 3 wt % silica content formed distinguishable voids and agglomerates. Fair distribution of silica nanoparticles and absence of residual solvents were observed by energy dispersive X‐ray and thermogravimetric analysis. Fourier transform infrared spectroscopy spectra confirmed the presence of new functional groups (N? H) and (O? H) bonds. The X‐ray diffraction pattern revealed the polymer‐particle interactions, the formation of rigidified polymer chain, and nanostructured silicon crystals. Further, the thermogravimetric analysis results revealed thermal stability enhancement while differential scanning calorimetry results of increased glass transition temperatures confirmed the presence of rigidified polymer chain. Furthermore, enhancements in mechanical strength of the membranes were observed. Moreover, at all feed pressures, increased CO₂, N₂, and CH₄ gas permeation was observed. At 6 bar feed pressure, the CO₂/N₂ and CO₂/CH₄ ideal selectivities of PC membranes with 3 wt % silica loading have increased from 19.2 to 38.0 and 29.2, respectively. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 45310.     

Review on design,preparation and performance characterization of gelled fuels for advanced propulsion

With the increasing demand for high-performance and safe fuels in aerospace propulsion systems, gelled fuels have attracted increasing attention. Because of their unique structure, gelled fuels exhibit the advantages of both solid and liquid fuels, such as high energy density, controllable thrust and storage safety. This review provides an overview on design, preparation and performance characterization of gelled fuels. The composition, preparation process and gelation mechanism of gelled high-energy-density fuels are described. Considering these aspects, the rheology and flow behavior of gelled fuels is summarized in terms of the shear thinning property, dynamic viscoelasticity and thixotropy. Moreover, the progress of atomization of gelled fuels is reviewed with a focus on the effect of atomizing nozzles. In addition, the experiments and theoretical models of single droplet combustion and combustor combustion are described. Finally, research directions for the development and application of gelled fuels are suggested.     

Poly(lactic acid)/opal-methacryloylpropyltrimethoxysilane-polystyrene graft polymer composites: preparation,characterization, and performance

Iranian Polymer Journal - Opal-methacryloylpropyltrimethoxysilane-polystyrene graft polymer (opal-MPS-PS) was synthesized using coupling method and solution polymerization. The results of...     

胃镜检查用多功能消泡乳的制备及性能评价

合成有机硅消泡剂、平平加A-20、柔软剂SG中加入少量纯化水,制成复合乳化剂。将盐酸丁卡因加入甲基纤维素中,制成胶液。将复合乳化剂加入胶液中,用高速乳化法乳化。加入醋酸氯已定、单糖浆制备胃镜检查用多功能消泡乳,并评价其消泡及抑泡性能。结果表明,高速乳化法制得的胃镜检查用多功能消泡乳质量稳定,消泡及抑泡性能良好,为临床提供实用新制剂。最优处方为:合成有机硅消泡剂3%,甲基纤维素20%,平平加A-20∶柔软剂SG=1∶6(体积比)。     

胃镜检查用多功能消泡乳的制备及性能评价

合成有机硅消泡剂、平平加A-20、柔软剂SG中加入少量纯化水,制成复合乳化剂。将盐酸丁卡因加入甲基纤维素中,制成胶液。将复合乳化剂加入胶液中,用高速乳化法乳化。加入醋酸氯已定、单糖浆制备胃镜检查用多功能消泡乳,并评价其消泡及抑泡性能。结果表明,高速乳化法制得的胃镜检查用多功能消泡乳质量稳定,消泡及抑泡性能良好,为临床提供实用新制剂。最优处方为:合成有机硅消泡剂3%,甲基纤维素20%,平平加A-20∶柔软剂SG=1∶6(体积比)。     

普通及窄分布醇醚羧酸盐氧化法制备及性能研究

以普通及窄分布醇醚、氧气和氢氧化钠为原料氧化法合成普通及窄分布醇醚羧酸盐,催化剂为炭负载多组分催化剂,优化普通及窄分布AEO9(9EO醇醚)合成工艺条件,同时考察了系列窄分布醇醚羧酸盐在不同pH值下的表面张力、泡沫性、润湿性能。结果表明,窄分布AEO9的优化反应条件为:反应温度70℃,氧压0.03 MPa,反应转速600 r/min,原料摩尔比n(窄分布AEO9)∶n(NaOH)=1∶1.02。此时产率达到95%;窄分布AEC9对比普通AEC9具有更窄的凝胶相区;酸性条件下,窄分布AEC9(9EO醇醚羧酸盐)30 s泡沫体积490 mL,远大于普通AEC9泡沫体积330 mL,中性及碱性条件下,窄分布AEC9发泡性弱于普通AEC9。     

普通及窄分布醇醚羧酸盐氧化法制备及性能研究

以普通及窄分布醇醚、氧气和氢氧化钠为原料氧化法合成普通及窄分布醇醚羧酸盐,催化剂为炭负载多组分催化剂,优化普通及窄分布AEO9(9EO醇醚)合成工艺条件,同时考察了系列窄分布醇醚羧酸盐在不同pH值下的表面张力、泡沫性、润湿性能。结果表明,窄分布AEO9的优化反应条件为:反应温度70℃,氧压0.03 MPa,反应转速600 r/min,原料摩尔比n(窄分布AEO9)∶n(NaOH)=1∶1.02。此时产率达到95%;窄分布AEC9对比普通AEC9具有更窄的凝胶相区;酸性条件下,窄分布AEC9(9EO醇醚羧酸盐)30 s泡沫体积490 mL,远大于普通AEC9泡沫体积330 mL,中性及碱性条件下,窄分布AEC9发泡性弱于普通AEC9。     

The preparation and characterization of high performance Ag/C oxygen electrocatalysts

The factors influencing the spatial distribution of metal catalyst on catalyst substrates have been investigated by studying the wettability, drying process and chemical interaction between the catalytic metallic salt solution and substrate, using AgNO₃/graphite as a model system. AgNO₃ reacts with graphite at temperatures above 100°C and hence very uniform dispersion of Ag on graphite is achieved by simple thermal treatment. On the other hand, for other systems which do not involve chemical reaction, such as H₂PtCl₆/graphite, freeze-drying gives better results. Teflon bonded electrodes prepared from impregnated catalysts containing 10% Ag on C gave 800m A/cm² at 0·84 V for the reduction of oxygen in 5nKOH at room temperature.     

Ti基碳氮共掺杂TiO2的制备、结构表征及光催化氯苯废气性能

以钛酸四丁酯为钛源、葡萄糖和尿素作为掺杂剂,采用水热-溶胶凝胶法制备了碳氮共掺杂TiO₂光催化剂,研究了该催化剂的结构特性及其对氯苯(CB)废气的转化性能。响应面法分析了C、N与钛酸四丁酯的添加比例对TiO₂催化CB的影响,获得了C和Ti物质的量比0.49、N和Ti物质的量比0.28时,该催化剂对CB的转化效率相对较高。利用XRD、TEM等对催化剂结构以及形貌进行表征表明:C/N共掺杂TiO₂为锐钛矿和金红石混合晶型,比表面积较大,吸收波长红移至500 nm。在反应介质相对湿度10%、CB初始浓度 50 mg·m^-3、反应时间60 s时,催化转化率93.5%;制备的催化剂在相对湿度10%~60%范围内对CB均具有较好的去除效果。稳定性实验表明,连续测试10 h对CB的转化率略微下降。     

WPU/CB/GO nanocomposites: in situ polymerization preparation,thermal, and anticorrosion performance evaluation

In this paper, composite fillers including graphene oxide and carbon black had been applied to modify pure waterborne polyurethane (WPU) and a new nanocomposite was prepared by in situ polymerization, whose structure was characterized by Fourier transform infrared spectroscopy that demonstrated interfacial interactions existing between the filler particles and the hard segments of WPU chains. Meanwhile, thermal properties of prepared nanocomposites were enhanced after adding composite fillers as shown in the results of thermogravimetric analysis and differential scanning calorimetry curves, which could be explained by several factors including strong interface interaction between organic phase and inorganic phase verified by infrared spectra and scanning electron microscopy as well as transmission electron microscopy, good dispersion and barrier effect of the composite fillers, reinforced crosslinking density of the system. Additionally, the contact angle and anticorrosion performance of the nanocomposite films were heightened after adding fillers. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48716.     

A novel lead ion‐imprinted chelating nanofiber: Preparation,characterization, and performance evaluation

A novel Pb(II) ion‐imprinted chelating nanofibers (nIIP), synthesized by combining electrospinning with surface ion imprinting technique, was reported in this study. nIIP was characterized with Fourier transmission infrared spectrometry and scanning electron microscopy, respectively. The performance of nIIP for Pb(II) sorption was conducted through a batch adsorption experiments. Experimental data showed that adsorption capacity of nIIP was much higher than that of non‐ion imprinted chelating acrylic microfibers (mNIP) derived from commercial available acrylic microfibers, and adsorption behaviors agreed well with pseudo‐second‐order kinetic and Langmuir isotherm model. The values of Gibbs free energy change derived from experimental data suggested that the adsorption Pb(II) on nIIP is spontaneous and favorable at high temperature. In addition, nIIP had the highest selectivity among three tested fibrous adsorbents for Pb(II) from binary metal solution, the selectivity coefficients for Pb(II) from binary metal solution of Pb(II)/Cu(II), Pb(II)/Ni(II), and Pb(II)/Cd(II) onto nIIP were 47, 101, and 162, respectively. Besides, a forty adsorption/desorption cycles revealed that nIIP was a promising recyclable adsorbent. In conclusion, the novel nIIP is a highly effective adsorbent for enrichment and separation of Pb(II) in the presence of competitive ions in aqueous solution, and it is potential to be applied for recovering metals from heavy metal polluted industrial wastewater such as Pb(II)/Cd(II), Pb(II)/Ni(II), and Pb(II)/Cu(II) polluted wastewater. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41507.     

UV-curable waterborne polyurethane-acrylate: preparation, characterization and properties

The waterborne polyurethane-acrylate (PUA) oligomer was firstly prepared based on isophorone diisocyanate (IPDI), polyether polyol (NJ-210), dimethylol propionic acid (DMPA) and hydroxyethyl methyl acrylate (HEMA) via in situ and anionic self-emulsifying method. The UV-curable polyurethane-acrylate (UV-PUA) was obtained with oligomer, monomers (BA and TPGDA) and photoinitiator Darocur 1173. FT-IR, DSC and TGA were employed to investigate the structures and thermal properties of the UV-PUA films. The effects of BA/TPGDA (R) value, the content of Darocur 1173 and the UV curing time on the performances were investigated. Some mechanical performances, solvent resistance and the gel content of UV-PUA films were measured. When the ratio of BA/TPGDA was 5/5, the UV-PUA film had the best solvent (water, alkali and ethanol) resistances. Besides, with the ratio of the BA/TPGDA increasing, the surface drying time increased. When the content of Darocur 1173 was 4%, the gel content achieved the maximum while the surface drying time achieved the minimum. The obtained UV-curable polyurethane-acrylates are promising as oligomers for UV-curable coatings, plastics, inks and adhesives.     

Properties,characterization and preparation of halogenated aromatic polyamides

This paper describes certain wholly aromatic polyamides based on 1,3-diamino-4-halobenzenes and 1,3-diamino-4,6-dihalobenzenes, and on isophthaloyl and terephthaloyl chloride by means of low temperature solution polymerization. We set out to study the influence of the kind of halogen (F, Cl or Br) and the type of substitution (mono or di) in the diamine moiety with regard to solubility, water uptake and thermal and mechanical properties. The materials are characterized with respect to chemical structure and purity by elemental analysis, infrared (FT-IR) and nuclear magnetic resonance (NMR) spectroscopic techniques, and special attention is paid to the sequence distribution (constitutional order) of polymers derived from non-symmetric monohalogen-substituted diamines, and their influence on the above-mentioned properties.     

新型压裂液用有机硼交联剂的合成、表征与性能评价

通过实验研究合成了有机硼交联剂ABE-30,并通过核磁氢谱、核磁硼谱与红外光谱等手段对ABE-30进行分析表征,推测出产物具有簇状配位的化学结构。研究了ABE-30交联剂与胍胶溶液的交联性能,并对交联体系的耐温耐剪切性能进行了研究。结果表明,与常规硼酸钠交联剂相比,合成交联剂ABE-30能与低浓度胍胶有效交联,交联体系具有良好的热稳定性与耐剪切性能,具有良好的应用前景。     

新型压裂液用有机硼交联剂的合成、表征与性能评价

通过实验研究合成了有机硼交联剂ABE-30,并通过核磁氢谱、核磁硼谱与红外光谱等手段对ABE-30进行分析表征,推测出产物具有簇状配位的化学结构。研究了ABE-30交联剂与胍胶溶液的交联性能,并对交联体系的耐温耐剪切性能进行了研究。结果表明,与常规硼酸钠交联剂相比,合成交联剂ABE-30能与低浓度胍胶有效交联,交联体系具有良好的热稳定性与耐剪切性能,具有良好的应用前景。