For the production of reactive polyurethane cross-linkinger and curing agents, 2, 4-diisocyanate toluene （TDI） terpolymer, which possesses the rigid structures of hexatomic ring and three reactive functional groups,...For the production of reactive polyurethane cross-linkinger and curing agents, 2, 4-diisocyanate toluene （TDI） terpolymer, which possesses the rigid structures of hexatomic ring and three reactive functional groups, was synthesized and characterized by the Fourier transform infrared （FFIR）, the gel permeation chromatography （GPC） and the chemical analysis methods. The reaction conditions were studied and optimized. A tracking research on the polymerization process of TDI was taken by using the GPC. The formation processes of the terpolymer, oligomers and higher-polymers were also dealt with. Results show that the TDI terpolymer can be prepared in the presence of Cat-3 catalyst and at the reaction temperature of （60 ±2）℃. The reaction time is short, its outcomes have narrow molecular weights distribution, namely molecular weights from 530 to 550, Mw/Mn =1.10, and the mass fraction of NCO is （25. 0 ± 0. 5）%. With the reaction time prolonging, however, TDI can be further higher-polymedzed to form higher-polymers. Benzoyl chloride （0. 4%, mass fraction）, as the stabilizing agent, can effectively inhibit the occurrence of higher-polymerization. The obtained TDI terpolymer can be stable for more than half a year.展开更多
利用海藻酸钠(SA)与硫酸钙反应产生的三维网状凝胶结构将水和偏二甲肼(UDMH)包埋在内部的特性,可将SA/硫酸钙/水作为处理偏二甲肼的新型洗消剂。通过对不同金属离子作交联剂的比较,发现Ca^(2+)的效果最好,10s左右即可固化。通过正交实...利用海藻酸钠(SA)与硫酸钙反应产生的三维网状凝胶结构将水和偏二甲肼(UDMH)包埋在内部的特性,可将SA/硫酸钙/水作为处理偏二甲肼的新型洗消剂。通过对不同金属离子作交联剂的比较,发现Ca^(2+)的效果最好,10s左右即可固化。通过正交实验优化了UDMH洗消剂的配比,各因素对UDMH挥发量的影响顺序为水>硫酸钙>SA,5 mL UDMH最佳洗消配比为0.75 g SA、0.20 g硫酸钙、30.00mL水。25℃时UDMH的逸出量仅为331.88mg/m^3。SA/硫酸钙/水相比于传统粉末洗消剂中效果较好的活性炭,其UDMH的挥发量仅为活性炭的21.7%,价格也仅为活性炭的2.2%,形成的凝胶可通过高温焚烧或溶解的方式去除。展开更多
The removal of chromium（Vl） from an aqueous solution using persimmon gel was examined. The amount of chromium（VI） removed was strongly affected by the pH of the solution, with all ehromium（VI） being removed at p...The removal of chromium（Vl） from an aqueous solution using persimmon gel was examined. The amount of chromium（VI） removed was strongly affected by the pH of the solution, with all ehromium（VI） being removed at pH 2 or lower. However, in a solution containing, 15 mg dry weight of immobilized persimmon gel, the amount of removed chromium（VI） decreased as the pH increased. A part of chromium（VI） was reduced another oxidation stage, mainly chromium（III）, by immobilized persimmon gel. The amount of reduced chromium（III） in the solution was increased with decreasing the pH of the solution. As a result, the amount of total chromium removed was maximal at pH 2. The amount of chromium removed were affected by the chromium concentration and the amount of gel. The maximal amount of chromium removed by the column system was also discussed.展开更多
This article is intended to provide an overview of recent progress in the studies of cholesterol-based low-molecular mass gelators (LMMGs) with unusual properties,in particular,gelation and selective gelation at room ...This article is intended to provide an overview of recent progress in the studies of cholesterol-based low-molecular mass gelators (LMMGs) with unusual properties,in particular,gelation and selective gelation at room temperature,gel emulsions and gel film formation,etc.Potential applications of the LMMGs in spilled oil collection and water purification are briefly presented.展开更多
In the present research,enzyme encapsulated hydrogels（single gels and double network gels）and enzyme immobilized magnetic beads,which allow high-throughput screening,were fabricated and evaluated in terms of the pre...In the present research,enzyme encapsulated hydrogels（single gels and double network gels）and enzyme immobilized magnetic beads,which allow high-throughput screening,were fabricated and evaluated in terms of the preservation,precision, and repeatability of enzyme activity.The fabricated gels and magnetic beads were analyzed in a 96-well microassay plate.Trypsin was successfully encapsulated in both types of gels and immobilized to the magnetic beads.However,pepsin,either encapsulated in the gels or immobilized to the magnetic beads,could not react with its substrates.The adaptability to various enzymes （e.g.,trypsin,β-glucuronidase,and CYP1A1）in the single gels and magnetic beads was superior to that in double network gels.However,the soak out of the enzymes was observed in the single gels.The double network gels could encapsulate trypsin,whereas the fabrication of the other enzymes（e.g.β-glucuronidase,CYP1A1,and pepsin）failed because of the inactivation of the enzymes by acryl amide and ammonium peroxodisulfate,which are the components of the gel formulation. The enzyme reaction in the magnetic beads exhibited the highest efficiency among the three fabrication methods.Furthermore, the stability of the enzymes immobilized to the magnetic beads was better than that fabricated by the other methods,and the activities of trypsin andβ-glucuronidase did not decline for up to one week.In addition,in the magnetic beads,the activities of trypsin andβ-glucuronidase can be well repeated.Hence,although the adaptability of the double network gels to various enzymes is currently limited,the efficiency of the enzyme encapsulation can be improved by optimizing the formulation of acryl amide gels.展开更多
文摘For the production of reactive polyurethane cross-linkinger and curing agents, 2, 4-diisocyanate toluene （TDI） terpolymer, which possesses the rigid structures of hexatomic ring and three reactive functional groups, was synthesized and characterized by the Fourier transform infrared （FFIR）, the gel permeation chromatography （GPC） and the chemical analysis methods. The reaction conditions were studied and optimized. A tracking research on the polymerization process of TDI was taken by using the GPC. The formation processes of the terpolymer, oligomers and higher-polymers were also dealt with. Results show that the TDI terpolymer can be prepared in the presence of Cat-3 catalyst and at the reaction temperature of （60 ±2）℃. The reaction time is short, its outcomes have narrow molecular weights distribution, namely molecular weights from 530 to 550, Mw/Mn =1.10, and the mass fraction of NCO is （25. 0 ± 0. 5）%. With the reaction time prolonging, however, TDI can be further higher-polymedzed to form higher-polymers. Benzoyl chloride （0. 4%, mass fraction）, as the stabilizing agent, can effectively inhibit the occurrence of higher-polymerization. The obtained TDI terpolymer can be stable for more than half a year.
文摘利用海藻酸钠(SA)与硫酸钙反应产生的三维网状凝胶结构将水和偏二甲肼(UDMH)包埋在内部的特性,可将SA/硫酸钙/水作为处理偏二甲肼的新型洗消剂。通过对不同金属离子作交联剂的比较,发现Ca^(2+)的效果最好,10s左右即可固化。通过正交实验优化了UDMH洗消剂的配比,各因素对UDMH挥发量的影响顺序为水>硫酸钙>SA,5 mL UDMH最佳洗消配比为0.75 g SA、0.20 g硫酸钙、30.00mL水。25℃时UDMH的逸出量仅为331.88mg/m^3。SA/硫酸钙/水相比于传统粉末洗消剂中效果较好的活性炭,其UDMH的挥发量仅为活性炭的21.7%,价格也仅为活性炭的2.2%,形成的凝胶可通过高温焚烧或溶解的方式去除。
文摘The removal of chromium（Vl） from an aqueous solution using persimmon gel was examined. The amount of chromium（VI） removed was strongly affected by the pH of the solution, with all ehromium（VI） being removed at pH 2 or lower. However, in a solution containing, 15 mg dry weight of immobilized persimmon gel, the amount of removed chromium（VI） decreased as the pH increased. A part of chromium（VI） was reduced another oxidation stage, mainly chromium（III）, by immobilized persimmon gel. The amount of reduced chromium（III） in the solution was increased with decreasing the pH of the solution. As a result, the amount of total chromium removed was maximal at pH 2. The amount of chromium removed were affected by the chromium concentration and the amount of gel. The maximal amount of chromium removed by the column system was also discussed.
基金supported by the National High-Tech Research & Devel-opment Program of China (863 Project) (2007AA03Z349)the National Natural Science Foundation of China (20902055,20927001,91027017)the 13115 Project of Shaanxi Province (2010ZDKG-89)
文摘This article is intended to provide an overview of recent progress in the studies of cholesterol-based low-molecular mass gelators (LMMGs) with unusual properties,in particular,gelation and selective gelation at room temperature,gel emulsions and gel film formation,etc.Potential applications of the LMMGs in spilled oil collection and water purification are briefly presented.
基金The Global COE Program from the Ministry of Education,Science,Sports,and Culture of Japan.
文摘In the present research,enzyme encapsulated hydrogels（single gels and double network gels）and enzyme immobilized magnetic beads,which allow high-throughput screening,were fabricated and evaluated in terms of the preservation,precision, and repeatability of enzyme activity.The fabricated gels and magnetic beads were analyzed in a 96-well microassay plate.Trypsin was successfully encapsulated in both types of gels and immobilized to the magnetic beads.However,pepsin,either encapsulated in the gels or immobilized to the magnetic beads,could not react with its substrates.The adaptability to various enzymes （e.g.,trypsin,β-glucuronidase,and CYP1A1）in the single gels and magnetic beads was superior to that in double network gels.However,the soak out of the enzymes was observed in the single gels.The double network gels could encapsulate trypsin,whereas the fabrication of the other enzymes（e.g.β-glucuronidase,CYP1A1,and pepsin）failed because of the inactivation of the enzymes by acryl amide and ammonium peroxodisulfate,which are the components of the gel formulation. The enzyme reaction in the magnetic beads exhibited the highest efficiency among the three fabrication methods.Furthermore, the stability of the enzymes immobilized to the magnetic beads was better than that fabricated by the other methods,and the activities of trypsin andβ-glucuronidase did not decline for up to one week.In addition,in the magnetic beads,the activities of trypsin andβ-glucuronidase can be well repeated.Hence,although the adaptability of the double network gels to various enzymes is currently limited,the efficiency of the enzyme encapsulation can be improved by optimizing the formulation of acryl amide gels.
