Porous alumina ceramic via gelcasting based on2-hydroxyethyl methacrylate dissolved in tert-butyl alcohol

To obtain porous alumina ceramic with high strength,a novel gelcasting system based on 2-hydroxyethyl methacrylate(HEMA)dissolved in tert-butyl alcohol(TBA)was developed.The polymerization of the HEMA-TBA gelcasting system,the thermal behavior of obtained green body,and the microstructures and mechanical properties of the sintered bodies were investigated by rheometer,TG-DSC,SEM and bending strength testing,respectively.The results show that,(1)10 mg/mL of the initiator(benzoyl peroxide)is the optimal amount for polymerization of this gelscasting system at 25 ℃;(2)The alumina suspension of the HEMA-TBA gelcasting system showing shear-thinning behavior is sufficiently low for gelcasting process;(3)The bending strength of porous alumina ceramic samples,whose porosities range from 42% to 56%,is from(8±0.5)to(91±4.5)MPa.

Tert-butylation of Toluene with Tert-butyl Alcohol over Realuminated H-mordenite Zeolite

The realuminated H-mordenite catalysts （HM1-4） treated with different concentrations of NaOH and NaAlO2 aqueous solutions were prepared, and characterized by inductively coupled plasma （ICP）, X-ray diffraction （XRD）, Fourier transform-infrared spectroscopy （FT-IR） and temperature-programmed desorption of ammonia, They are of lower Si/AI ratio and higher acid amount while keeping a high relative crystallinity. Their catalytic performances were evaluated with the liquid-phase tert-butylation of toluene with tert-butyl alcohol in a 100 ml stainless steel batch reactor equipped with a stirrer. HM2 zeolite catalyst, obtained by treating HM in 0.1 mol.L-1 NaOH followed by 0.05 mol·L^-1 NaAlO2 aqueous solution, shows a higher catalytic activity because of its highest acid amount. For HM2 catalyst the influences of reaction conditions on catalytic performance were investigated. The conversion of toluene is 50.3% and the selectivity ofp-tert-butyltoluene is 74.7% at a temperature of 180℃, 2 of molar ratio of tert-butyl alcohol to toluene, 4h of reaction time and 0.2 of M（catalyst）/M（toluene）.

The Inhibition Effect of Tert-Butyl Alcohol on the TiO_2 Nano Assays Photoelectrocatalytic Degradation of Different Organics and Its Mechanism

The inhibition effect of tert-butyl alcohol(TBA), identified as the·OH radical inhibitor, on the TiO_2 nano assays(TNA) photoelectrocatalytic oxidation of different organics such as glucose and phthalate was reported. The adsorption performance of these organics on the TNA photoelectrode was investigated by using the instantaneous photocurrent value, and the degradation property was examined by using the exhausted reaction. The results showed that glucose exhibited the poor adsorption and easy degradation performance, phthalate showed the strong adsorption and harddegradation, but TBA showed the weak adsorption and was the most difficult to be degraded. The degradation of both glucose and phthalate could be inhibited evidently by TBA. But the effect on glucose was more obvious. The different inhibition effects of TBA on different organics could be attributed to the differences in the adsorption and the degradation property. For instance, phthalate of the strong adsorption property could avoid from the capture of·OH radicals by TBA in TNA photoelectrocatalytic process.

Isobaric Vapor–Liquid Equilibrium for tert-Butyl Alcohol + Water + Propane-1,3-Diol + 1-Ethyl-3-Methylimidazolium Chloride at 101.3 kPa

In this study, we used a mixture of organic liquid propane-1,3-diol and ionic liquid 1-ethyl-3-methylimidazolium chloride([emim]Cl) as the entrainer to separate tert-butyl alcohol(TBA) + water. We measured the isobaric vapor–liquid equilibrium(VLE) for the quaternary system TBA + water + propane-1,3-diol + [emim]Cl at 101.3 kPa, and found the VLE data to be well correlated with the nonrandom two-liquid model. These results show that the mixed solvent of propane-1,3-diol + [emim]Cl can increase the relative volatility of TBA to water and break the azeotropic point. We found no notable synergetic effect between them, and observed that the liquid mixed solvent of propane-1,3-diol and [emim]Cl had lower viscosity than [emim]Cl, which makes it a promising entrainer for separating the TBA + water azeotrope in industrial applications.

血清m-AST、TBA检测在酒精性肝病诊断中的应用

目的实验探讨m-AST、TBA等临床化学指标检测与酒精性肝病的关系。方法用HITACHI7600-020生化分析仪对56例酒精性肝病组和53例急性、慢性病毒性肝炎组及50例对照组血清中m-AST、AST、TBA、餐后2hTBA、ALT等临床化学指标进行检测。结果酒精性肝病组的m-AST、TBA、餐后2hTBA、m-AST/AST、2hTBA/TBA水平明显高于对照组(P<0.01)。m-AST/AST、2hTBA/TBA明显高于急性、慢性肝炎组(P<0.01)。而ALT等其它临床化学指标虽然高于对照组,但缺乏疾病组间鉴别的特异性依据。结论m-AST、AST、m-AST/AST、TBA、餐后2hTBA的水平检测在诊断酒精性肝病早期中具有重要的意义。

Degradation of MTBE and TBA by a new isolate from MTBE-contaminated soil

Methyl ten-butyl ether （MTBE）, a gasoline additive, possesses serious problems to the environmental health. In the present study, a bacterial culture named A-3 which could effectively degrade MTBE was isolated from the MTBE contaminated soil. The isolate was identified as Chryseobacterium sp., a new species capable of degrading MTBE. In order to enhance its degradation ability, selected environment factors were investigated. The results showed that the optimal temperature was in the range of 25-30℃, the pH was 7.0, the inoculum size was 2 × 10^8 CFU/ml and the optimal concentration of MTBE was from 50 to 100 mg/L. The maximum MTBE utilization rate （Vmax） was 102 nmol MTBE/（mg cell protein.h）. Furthermore, it was found that the isolate could also degrade tert-butyl alcohol （TBA）. The degradation rates of TBA were much faster than those of MTBE. The additional TBA would lead to the decrease of the initial MTBE degradation rate and the inhibitory effect of TBA increased with the increase of TBA concentration. Similar protein profiles at least seven peptides were demonstrated after SDS-PAGE analysis of crude extracts obtained from the cells growing in MTBE and TBA culture.

Phenol Tert-Butylation Catalyzed by Zeolite H-Mordenite

Para-tert-butyl phenol (p-TBP) and 2,4-di-tert-butyl phenol (2,4-DTBP) are widely used for the preparation of antioxidants. Zeolite catalysts showed good performance for the synthesis of p-TBP and 2,4-DTBP. In this work, zeolite H-mordenite (HM) catalyst was prepared and the alkylation of phenol with tert-butyl alcohol over zeolite HM catalyst was investigated at different reaction conditions. It is found that increasing temperature enhances the selectivity to p-TBP and the optimum reaction temperature for phenol conversion is 438 K. Increasing flow rate decreases phenol conversion apparently while the selectivity to p-TBP has a little increase. The suitable tert-butyl alcohol/phenol molar ratio is 2. Lower alcohol/phenol molar ratios are beneficial to p-TBP while higher ones are helpful for producing 2,4-DTBP.

三甲胺基SO_3H-功能化离子液体催化对苯二酚叔丁基化反应

以三甲胺、1,3-丙烷磺内酯或1,4-丁烷磺内酯为原料,合成了三甲胺基SO3H-功能化离子液体(IL),采用NMR、TOF-MS、TG等手段表征了其结构和热稳定性。以对苯二酚(HQ)与叔丁醇(TBA)的烷基化反应为探针,考察了反应时间、HQ与TBA摩尔比、离子液体与HQ摩尔比、反应温度等因素对反应性能的影响,并考察了离子液体的重复使用性能。结果表明,在最佳反应条件T=343K,t=90min,n(HQ)∶n(TBA)∶n(IL)=2∶3∶1下,HQ的转化率可以达到68.4%,2-叔丁基对苯二酚(TBHQ)的选择性达到75.1%。离子液体重复使用6次,其活性基本不变。

叔丁醇基凝胶注模工艺制备轻质、高强莫来石多孔陶瓷

以叔丁醇为成型溶剂,莫来石粉为起始原料,采用凝胶注模成型方法制备出轻质、高强莫来石多孔陶瓷.莫来石多孔陶瓷中的孔隙形成于干燥过程中叔丁醇的快速挥发,孔隙分布均匀且相互连通.随烧结温度升高,气孔率、开气孔率和比表面积分别由77.8%、76.0%和10.39m2/g下降到67.6%、65.5%和4.26m2/g,而抗压强度则由3.29MPa显著提高到32.36MPa,材料孔径大小受烧结温度影响较小,孔径尺寸呈单峰分布,且几乎所有的气孔都为开口气孔,透气度与孔径尺寸具有一致的变化关系.莫来石多孔陶瓷在高气孔率条件下仍然保持高强度的主要原因是材料中均匀的孔隙结构、孔径尺寸小且相对集中、以及因烧结颈的形成在空间上所表现出的一种颗粒搭接骨架结构.

离子液体催化苯酚与叔丁醇烷基化反应

研究了SO3H-功能化离子液体的合成、表征及其催化苯酚与叔丁醇(TBA)烷基化反应的性能。考察了反应时间t、反应温度T、反应物摩尔比及离子液体(IL)用量等因素对反应性能的影响,并考察了离子液体的重复使用性能。结果表明,在T=70℃、t=420min、n(Phenol)∶n(TBA)∶n(IL)=1∶1∶1的优化反应条件下,苯酚的转化率可以达到79.6%,邻-叔丁基苯酚的选择性达到了52.4%。离子液体重复使用4次,其活性基本不变。

冻干溶液玻璃化转变温度的实验研究

本文利用差示扫描量热仪(DSC)研究了降温速率和溶质比对叔丁醇/蔗糖/水三元系统玻璃化转变温度Tg’的影响。实验结果表明,降温速率的增大会使溶液的玻璃化转变温度明显降低。对于10%叔丁醇/10%蔗糖/水溶液,当降温速率大于10℃/min时,Tg’为-42℃。对于叔丁醇与蔗糖的浓度比小于0.2的溶液,降温时叔丁醇不会发生结晶。

叔丁醇-水共溶剂冷冻干燥工艺及其在药剂学中的应用

目的介绍叔丁醇-水共溶剂冷冻干燥工艺及在药剂学研究中的应用。方法根据国内外相关文献报道,对叔丁醇-水共溶剂冷冻干燥工艺的特点进行了介绍,对其在国内外药剂学研究进展进行了综述。结果与结论叔丁醇-水共溶剂系统可以作为冷冻干燥的技术平台用于多种制剂的制备。

具有垂直孔道的壳聚糖乳酸盐海绵的制备及体外释药模型的拟合分析

先将壳聚糖(CH)经乳酸改性制成壳聚糖乳酸盐(LCH)以改善其溶解性,然后通过加入冰晶生长引导剂叔丁醇(TBA),在特制的定向冷冻装置中冻结,再经冷冻干燥后,制成了一种圆柱形的海绵体,其内部具有垂直方向上的孔道结构.通过控制叔丁醇的浓度,制备了具有不同孔径及孔隙率的海绵样品.以红霉素为模型药物,研究了具有自身降解溶蚀功能的LCH样品的体外释药模型,结果表明,LCH样品的释药过程主要分为基体溶蚀控释和药物后扩散2个阶段.其中基体控释阶段符合Couarraze释药模型.

H_3PO_4/MCM-41催化苯酚与叔丁醇气相烷基化反应(英文)

The catalytic performance of Al-MCM-41 containing 5-35 wt% H3PO4 was studied for the vapor phase alkylation of phenol with tert-butyl alcohol(TBA) from 383 to 493 K.4-Tert-butyl phenol was produced as the main product with moderate selectivity.The product distribution depends on the reaction temperature,number of acid sites,and the Brnsted to Lewis sites ratios.A lower molar ratio of reactants(TBA/phenol = 2) and a higher space velocity facilitated the production of 4-tert-butyl phenol.The influence of various parameters such as temperature,reactant feed molar ratio,feed rate,and time on stream were investigated for conversion yield and product selectivity.

超声降解含有叔丁醇石油化工废水的研究

研究了超声波降解含叔丁醇石油化工废水的过程，探讨了反应动力学模式。实验表明，在实验条件下超声波降解含叔丁醇石油化工废水能够达到较好的降解效果。CODcr的去除率随着超声辐射时间的延长而提高。体系不同的pH条件对反应也有不同的影响。同时，研究了US／H2O2，US／Fe^2＋．US／Fe^2＋／H2O2，US／S2O8^2-等不同体系对反应的影响，经比较，US／Fe^2＋／H2O2对整个反应有较明显的促进作用。分析了单独使用超声波降解该废水可生化性的变化情况。同时，发现超声波降解含叔丁醇的石油化工废水的反应符合假一级反应动力学模式。

固相量和冷冻温度对冷冻浇注SiC多孔陶瓷结构和性能的影响

多孔陶瓷是一种具有高比表面积、高渗透、耐腐蚀和生物相容性等优良性能的新型功能材料,在过滤分离、催化剂载体、多孔电极以及生物工程等领域具有广阔的应用前景。相较于传统的多孔陶瓷制备方法,冷冻浇注法具有工艺简单、环境友好以及材料适应强等优点,可以得到形状复杂且具有独特孔隙结构的多孔陶瓷部件。以叔丁醇为模板,通过冷冻浇注法制备了具有六方孔道结构的高气孔率碳化硅多孔陶瓷。利用扫描电子显微镜(SEM)分析了多孔陶瓷的孔结构特征,研究了固相量和冷冻温度对碳化硅多孔陶瓷显气孔率和强度的影响。结果表明:采用冷冻浇注工艺制备的SiC多孔陶瓷显气孔率均在65%以上,随着固相量的增加,多孔陶瓷的孔径与显气孔率减小,孔道数量增加,耐压强度增加;冷冻温度的降低造成多孔陶瓷的孔径尺寸减小,孔道数量增加,但显气孔率差别不大。当冷冻温度为-65℃时,多孔陶瓷沿着冷冻方向上形成较为明显的梯度孔分布。