介绍一种戊二醛含量的测定方法

本文介绍了一种简单快速的戊二醛含量的分析方法，这是利用了戊二醛还原四唑蓝形成甲而显色的原理。戊二醛在碱性条件下加热还原四唑蓝成为有色的甲，用乙酸乙酯萃取甲，再以分光光度法测定其含量。作者用此方法测定了国产２５％戊二醛水溶液含量为１４．７％，与作者用气相色谱法测定同一批号试剂戊二醛所得含量１６．１％相接近，但前者具简便快速的特点，适用于电镜工作者及一般生物实验室使用。     

环戊烯催化氧化合成戊二醛及其动力学

对在非水溶剂存在下过氧化氢一步催化氧化环戊烯制备戊二醛过程中的催化体系进行了研究。考察了具有脱水功能的Ｂ２Ｏ３的作用及用量，确立了具有优良催化性能的催化体系ＷＯ３－Ｂ２Ｏ３；实验测定了反应动力学数据，采用非线性回归Ｐｏｗｅｌ共扼法求得了反应动力学方程。在推荐的催化剂体系和工艺条件下，环戊烯转化率６７％，戊二醛收率６３％，选择性９１％。     

Use of Ozonated Water for Disinfecting Gastrointestinal Endoscopes

The reprocessing of endoscopes is a complex procedure due to their structural design. In the constant search for new antimicrobial substances, recent studies with ozone have yielded great benefits. The present study evaluated the effects of ozonated water used to disinfect endoscopes comparing its efficacy with the conventional technique (2% glutaraldehyde). According to the results obtained, when ozonated water was used (330 mg.min.L^?1), induced a 2 log reduction of the viable microorganisms under the conditions tested. Ozonated water was a potent gastrointestinal endoscopic sanitizer, suggesting it is a feasible alternative for disinfection.     

Effect of aldehydes on thermomechanical properties of gluten-based bioplastics

Protein–protein crosslinks play an important role in the design of biodegradable polymeric materials requiring suitable rheological and mechanical properties. The addition of aldehydes to the bioplastic formulation may result in their involvement in some form of protein cross-linking. The objective of this contribution is to evaluate the effect of adding some aldehydes (formaldehyde, glutaraldehyde and glyoxal) on the thermomechanical properties of gluten-based biodegradable polymeric materials processed by a mixing stage followed by compression moulding at 9 MPa and 130 °C. Different bioplastic probes were evaluated by means of DMA measurements, recording the elastic and loss moduli as a function of temperature and uniaxial tensile strength tests. Water absorption capacity and solubility under different extraction media of bioplastic specimens, were also evaluated. Solubility measurements were carried out in order to analyse the effect of the aldehyde on the nature of the interactions taking place in the system, being compared to those performed on blends previous to the moulding process. Glyoxal is the aldehyde that seems to produce bioplastics with best thermal and mechanical properties. This study would contribute to evaluate the potentials of adding aldehyde to gluten/plasticiser systems to control the microstructure and properties of the final bioplastics.     

蚕丝丝胶戊二醛固着工艺的研究

本文就戊二醛（ＧＡ法）丝胶固着工艺和减少丝胶固着丝的黄变程度进行了研究，提出了高温短时间浸渍加脱水冷堆的ＧＡ法丝胶固着生产工艺。研究结果表明：在酸性条件下，添加适量稀土元素，采用酸性盐类作ｐＨ调节剂，适当降低固着时的ｐＨ值，能有效地提高丝胶固着牢度和降低固着丝的黄变程度．在弱碱性条件下，添加适当的缓冲稳定剂，能提高丝胶固着牢度和减少黄变现象。     

Preparation of cross-linked sodium alginate microparticles using glutaraldehyde in methanol

Polymeric sodium alginate microparticles were prepared by precipitating sodium alginate in methanol, followed by cross-linking with glutaraldehyde. The extent of cross-linking was controlled by the time of exposure to glutaraldehyde. The topology of microparticles was characterized by scanning electron microscopy (SEM), which indicated smooth surfaces. The equilibrium swelling experiments were carried out in water to observe the effect of cross-linking and drug loading for better utility of microparticles. It was found that swelling decreased, but drug loading increased, with an increase in cross-linking of the matrix.     

Extraction of carbon 14-labeled compounds from plant tissue during processing for electron microscopy

Loss of ¹⁴C-labeled compounds from bean leaf tissue was monitored during all the stages of routine specimen preparation. No significant differences in extraction were associated with the use of acetone, ethanol, or dioxane as dehydration fluids. Fixation at low temperature increased the loss of label. Prolonged fixation in glutaraldehyde increased the loss, but fixation in osmium solutions for periods as long as 4 hr had no influence on extraction. Buffer rinses and dehydration fluids caused appreciable amounts of label to be extracted. The use of propylene oxide as transition fluid resulted in low extraction. Some embedding media caused the loss of small amounts of labeled compounds, but one of the media tested (LR-white) extracted significant amounts of label.     

High performance polymer chemical hydrogel-based electrode binder materials for direct borohydride fuel cells

Novel, cost-effective, high-performance, and environment-friendly electrode binders, comprising polyvinyl alcohol chemical hydrogel (PCH) and chitosan chemical hydrogel (CCH), are reported for direct borohydride fuel cells (DBFCs). PCH and CCH binders-based electrodes have been fabricated using a novel, simple, cost-effective, time-effective, and environmentally benign technique. Morphologies and electrochemical performance in DBFCs of the chemical hydrogel binder-based electrodes have been compared with those of Nafion^® binder-based electrodes. Relationships between the performance of binders in DBFCs with structural features of the polymers and the polymer-based chemical hydrogels are discussed. The CCH binder exhibited better performance than a Nafion^® binder whereas the PCH binder exhibited comparable performance to Nafion^® in DBFCs operating at elevated cell temperatures. The better performance of CCH binder at higher operating cell temperatures has been ascribed to the hydrophilic nature and water retention characteristics of chitosan. DBFCs employing CCH binder-based electrodes and a Nafion^®-117 membrane as an electrolyte exhibited a maximum peak power density of about 589 mW cm⁻² at 70 °C.     

浅绿色彩棉纤维改性研究

研究化学改性处理对天然浅绿色彩棉纤维性能的影响。通过碱处理和戊二醛交联对纤维品质较差的浅绿色彩棉纤维进行改性。测试了碱处理及戊二醛交联后浅绿色彩棉纤维的强伸性能、弹性回复率、回潮率及纤维形态结构。试验表明:经碱处理后,浅绿色彩棉纤维强伸性能、弹性回复率得到改善,用17%氢氧化钠溶液处理10 min的浅绿色彩棉纤维性能提高较显著;经戊二醛交联后,浅绿色彩棉纤维强度增强,断裂伸长率下降,且随着接枝率的增大,断裂伸长率趋于降低,弹性回复率趋于增大。     

吡喃法合成戊二醛(上)

戊二醛是一种有着广阔发展前景的精细化工产品,它的两个自由醛基非常活泼,能进行多种反应．被广泛应用在医药、油田、制革、食品、环境保护等领域。为了利用本公司具有丙烯醛原料的优势,积极开发高附加值的下游产品,进行了乙烯基乙醚和丙烯醛反应合成2-乙氧基-3,4-二氢吡喃及其水解制备戊二醛的研究．并在连续化吡喃合成和水解方面取得了一定的技术突破,形成了特有的戊二醛合成工艺。