乙醇提取-丙酮沉淀法提取分离茶皂素的工艺研究

以油茶饼粕为原料,采用乙醇提取-丙酮沉淀法对茶皂素进行提取分离。以茶皂素纯度和得率为考察指标,对乙醇体积分数、液料比、提取温度、提取时间、提取次数、提取液浓缩程度和丙酮用量等工艺参数进行了单因素优化。结果表明：体积分数95%的乙醇为提取溶剂,乙醇与预处理过的油茶饼粕液料比为9：1（mL：g）,提取温度为70℃,提取时间为4 h,提取次数为2次,提取液浓缩至刚好有固体析出,丙酮用量为4倍浓缩液体积量时提取分离效果较佳,得到的茶皂素纯度为85.17%,得率为9.82%。不同溶剂打浆对产品纯化效果的比较发现：丙酮、乙酸乙酯、无水乙醇、体积分数95%的乙醇作为打浆纯化溶剂用于提高茶皂素纯度效果均不明显。     

丙酮诱导不同形状的金纳米粒子整形

在HAuCl4-葡萄糖-丙酮体系中,丙酮不仅能起光敏剂、加速光化学还原Au(III)离子的反应,还能诱导已形成的金纳米粒子整形。整形过程伴随着明显的可见/近红外吸收光谱变化,并形成一些全新的纳米结构。实验结果表明,金纳米粒子的整形方式与初始金纳米粒子的形貌密切相关,对于球形的金纳米粒子,整形后形成纳米线;而对于锥形纳米粒子则形成金纳米片。     

工业苯酚丙酮装置氧化尾气的气相色谱分析

采用质量分数2.5%的邻苯二甲酸二壬酯和质量分数2.5%的硅藻土,以chromsorb G·DMCX(150~180μm)为担体的色谱填充柱进行分离,氢火焰离子化检测器进行检测,用峰面积外标法进行定量分析,同时对工业苯酚丙酮装置氧化尾气组成进行气相色谱分析。对色谱柱的选择、操作条件的优化、定性、定量分析,进样量和线性范围、最低检测限等实验项目进行了考察,实验结果表明此方法具有操作简单、分析速度快、分析成本低、重复性与准确性好等特点。     

PVA膜渗透汽化分离低浓度丙酮/水溶液的实验研究

采用聚乙烯醇（PVA）膜渗透汽化分离浓缩低浓度丙酮/水溶液,考察了原料液浓度、温度、膜后真空度等对PVA膜渗透通量和分离因子的影响。结果表明,随着原料液浓度的增加、温度和膜后真空度的升高,渗透通量和分离因子均呈增加的趋势,温度对渗透通量的影响基本符合Arrhenius方程。     

超声波辅助从浓缩磷脂中提取高纯粉状磷脂的研究

以大豆浓缩磷脂(CSP)为原料,丙酮为溶剂,提取高纯度粉状磷脂。针对传统有机溶剂法萃取制备粉状磷脂工艺过程中,物料粘度大,容易团聚成块,脱油操作极其困难,萃取效率低等问题,提出了超声波辅助均质萃取新技术。并对较佳的工艺操作条件的选择进行了研究。通过正交实验得出优化的条件为:萃取次数5次,萃取温度0℃,浓缩磷脂与丙酮之比为1/12g/mL,超声波辅助剪切转速5000r/min。产品丙酮不溶物可达98%以上。     

6-APA中残留丙酮、甲基异丁基酮的测定

采用直接进样色谱法测定,并用内标法（2-戊酮作内标物）定量,确定6-APA中残留丙酮、甲基异丁基酮的检测方法。经验证此法可准确测定6-APA中丙酮、甲基异丁基酮的残余量。     

Acetone transformation into methyl isobutyl ketone over Pt/HMFI catalysts. IV. Effect of density and strength of the acidic sites

Acetone transformation into methyl isobutyl ketone (MIBK) was studied using a fixed-bed dynamic reactor at 160°C, 1 atm pressure and acetone/H₂ molar ratio=3. The reaction was carried out over Pt/HMFI bifunctional catalysts, with 0.30 wt% of platinum which was supported over three aluminosilicates (Si/Al ratio=40, 95 and 160) and a borosilicate (Si/B ratio=44) with similar dispersion. The results show that catalytic properties depend greatly on density and strength of the acidic sites of the catalysts. Moreover, the limiting step of the MIBK synthesis reaction (aldolization of two acetone molecules) is carried out over the acidic sites of the aluminosilicates, but not over those of the borosilicate, which considerably affects reaction selectivity. This revised version was published online in July 2006 with corrections to the Cover Date.     

Claisen-Schimidt反应合成甲基桂酮的研究

在缩合剂和催化剂存在下 ,采用 Claisen Schimidt反应合成了甲基桂酮。考察了缩合剂浓度、催化剂用量、原料配比、反应温度和时间等因素对产物收率的影响 ,确定了最佳反应条件 ,产物收率≥ 85% ,纯度达98.3%。     

等离子体辅助丙酮低温氧化的研究

考虑到小分子含氧组分在等离子体助燃体系中重要的研究意义,本文以丙酮为研究载体,基于先进的分子束质谱诊断平台开展了研究．提供了详细的中间体组分信息,并基于此构建了丙酮等离子体的低温反应网络．结果表明,在等离子体放电激励的作用下,丙酮的燃料氢提取过程被加速,并且还伴随着明显的燃料碎片化过程．研究发现,无势垒反应在等离子体低温氧化的反应机制中十分重要．另外,本文还给出丙酮低温氧化在不同电压激励下的定量结果．     

Growth-temperature-dependent optical and acetone detection properties of ZnO thin films

Zinc oxide (ZnO) thin films were prepared onto glass substrates at moderately low growth temperature by two-stage spray pyrolysis technique. The effects of growth temperature on structural, optical and acetone detection properties were investigated with X-ray diffractometry, a UV-visible spectrophotometer, photoluminescence (PL) spectroscopy and a homemade gas sensor testing unit, respectively. All the films are polycrystalline with a hexagonal wurtzite phase and exhibit a preferential orientation along [002] direction. The film crystallinity is gradually enhanced with an increase in growth temperature. The optical measurements show that all the films are physically highly transparent with a transmittance greater than 82% in the visible range. The band gap of the film is observed to exhibit a slight red shift with an increasing growth temperature. The PL studies on the films show UV/violet PL band at ～ 395 nm. Among all the films investigated, the film deposited at 250 ℃ demonstrates a maximum sensitivity of 13% towards 20 ppm of acetone vapors at 300 ℃ operating temperature.