PC微流控芯片黏接筋与溶剂的协同辅助键合

为了在微流控芯片上形成封闭的微通道等功能单元,克服热压键合中微流控结构的塌陷和热压所致芯片微翘曲对后续键合的影响,提出了一种适用于硬质聚合物微流控芯片的黏接筋与溶剂协同辅助的键合方法。以聚碳酸酯(PC)微流控芯片为研究对象,通过热压法在PC微流控芯片上的微通道两侧制作凸起的黏接筋,通过化学溶剂丙酮微溶PC圆片的表面,然后将PC圆片与带有黏接筋的PC微流控芯片贴合、加压、加热,从而实现微流控芯片的键合。分析了键合机理,并对键合工艺参数进行了优化。实验结果表明:键合质量受丙酮溶剂溶解PC圆片的时间和键合温度的影响,能够保证键合质量的最佳键合温度为80~90°,溶解时间为35~45s,芯片的键合总耗时为3min。与已有键合工艺相比,所提出的黏接筋与溶剂辅助键合工艺有效提高了键合效率。该键合方法不仅适用于具有不同宽度尺寸微通道的微流控芯片,还可扩展用于不同材料的硬质聚合物微流控芯片。     

水性聚氨酯粘合剂中丙酮含量的测定

该方法选用401有机载体为固定相,装入柱长2m,内径3mm的玻璃或不锈钢色谱柱中,采用泵抽法装柱,通N2于190℃老化24h;以甲醇为内标,蒸馏水为溶剂,FID为检测器,对水性聚氨酯粘合剂样品中丙酮含量进行气相色谱分离和测定。结果表明:丙酮的标准偏差0.028;变异系数0.41%;回收率99.7%,线性相关系数r=0.9999。该方法测定速度快,结果准确,重现性好。     

降低烟用二醋酸纤维丝束残余丙酮含量的分析及措施

降低烟用二醋酸纤维丝束的残余丙酮含量,对提高丝束产品的质量有重要作用,运用纤维物料干燥原理,分析生产过程中烟用二醋酸纤维丝束残余丙酮与干燥、加湿的关系,同时结合干燥设备提出有效降低烟用二醋酸纤维丝束残余丙酮的方法和措施,具有实际的运用价值。     

乙酰丙酮比色法测定树脂类皮革化学品中游离甲醛的含量

本文论述了限制皮革化学品中游离甲醛含量的意义以及用乙酰丙酮比色法测定皮革化学品中游离甲醛含量的优越性和操作方法。     

Use of Sodium Alginate-Poly(vinyl pyrrolidone) Membranes for Pervaporation Separation of Acetone/Water Mixtures

Pervaporative separation of acetone from water at a concentration range of 0–100 wt% were studied using sodium alginate (NaAlg)/Poly vinyl pyrrolidone (PVP) membranes. Membranes were prepared in different ratios (w/w) (100/0, 95/5, 90/10, 85/15, 80/20, 75/25) of NaAlg/PVP by crosslinking with CaCl₂. Experimental studies were carried out to investigate the effects of the operating temperature, feed composition, and membrane thickness on the pervaporation performance. The optimum operating temperature, membrane thickness, NaAlg/PVP ratio, and feed composition were determined as 40°C, 70 µm, 75/25 (w/w), and 20 wt% acetone, respectively. The effect of PVP content in the membranes was investigated on pervaporation performance. The permeation rate was increased with increasing the PVP content; however, there was no appreciable change about the separation factor. The permeation rate and separation factor values were found to be in the range of 0.304–1.023 kg/m² h and 16–57, respectively. In addition, the sorption-diffusion properties of the alginate membranes were investigated at the operating temperature and the feed composition. It was found that the sorption selectivity was the dominant factor for the separation of acetone/water mixtures.     

Effect of organic solvents on growth of freshwater algae

The impact of acetone, methanol, ethanol and dimethyl sulfoxide (DMSO) as carrier solvents on two species of algae was investigated. Scenedesmus quadricauda of green algae and Anabaena flos‐aquae of blue green algae were subjected to different concentrations of the studied solvents which ranged from 0.01 to 7.29 mL/L for 10 days in batch studies. The data recommended the use of acetone, ethanol and methanol than dimethyl sulfoxide in this order as a carrier solvent for chemical toxicity tests using a maximum concentration of 7.29 mL/L which represents 0.729% (volume/volume) in the algal bioassay test.     

2-甲氧基丙烯生产中有关体系的共沸点研究

利用基于精馏原理的加压共沸点测定装置，测定了2-甲氧基丙烯(MPP)与甲醇或丙酮二元体系在减压、常压及加压条件下的共沸点数据，并对数据进行了关联。从关联的结果可知，该体系共沸组成与共沸温度、压力的对数及共沸温度的倒数均呈良好的线性关系，计算结果与实验值符合良好。随着压力的降低，这两个二元体系中MPP的含量都增加，说明在减压条件下更利于MPP的分离和提纯。特别是MPP-丙酮体系，在49．7kPa下，其MPP的摩尔分数已达到0．997。这项研究为MPP工业化过程中共沸混合物的分离、提纯，以及共沸精馏、反应精馏等工艺与装置的研究与设计提供了重要的基础数据和参考依据。     

微波快速合成1,5-二芳基-1,4-戊二烯-3-酮

以芳醛、丙酮为原料，在碱性条件下经微波辐射快速合成了一系列1，5-二芳基-1，4-戊二烯-3-酮，反应在1min左右完成，得率61％—86％。     

以活性炭纤维为载体催化剂降解丙酮的研究

以活性炭纤维为载体，用TiOSO4为原料自制催化剂与P25光催化降解丙酮进行比较。实验结果表明，以TiOSO4为原料自制催化剂降解丙酮效率比以P25为催化剂降解丙酮效率高。由于工业用硫酸氧钛易得且价格便宜，工业化前景看好，这有可能为制备TiO2光催化剂提供一条合适的工业化生产途径。     

Antioxidant Activity of Mycelia from Aspergillus candidus

The antioxidant activity of mycelia extracts produced from the submerged cultures of Aspergillus candidus CCRC 31543 was investigated. Inhibition of peroxidation (IP%) of mycelia acetone extracts (MAE) in linoleic acid peroxidation was equal to that of BHA and significantly (p < 0.05) higher than that of α-tocopherol. As measured by the Rancimat method in lard, MAE showed marked antioxidant activity with an induction time of 8.4 h at a concentration of 200 μg/mL. MAE also exhibited strong scavenging effect on α,α-diphenyl-β-picrylhydrazyl radicals and marked reducing power. HPLC-DAD analysis suggested that MAE possessed the antioxidant components 3,3"-dihydroxyterphenyllin, 3-hydroxyterphenyllin, and candidusin B.