Construction of functional aliphatic polycarbonates for biomedical applications

Aliphatic polycarbonates are one important kind of biodegradable polymers and have been commonly used as integral components of engineered tissues, medical devices and drug delivery systems. As far as the biomedical application is concerned, traditional aliphatic polycarbonates usually suffer from the strong hydrophobicity, deficient functionality, and insufficient compatibility with cell/organs. Consequently, the application is quite limited in scope. Due to the imparted appealing properties, aliphatic polycarbonates bearing specifically designed functional/reactive groups attract great interest from researchers in the recent years. The present review outlines the development up to date concerning the design and biomedical application of functional aliphatic polycarbonates, with an emphasis on their ring-opening (co)polymerization preparation.     

羧甲基纤维素钠(CMC)在食品工业应用的情况和研究动态

本文综述了近几年羧甲基纤维素钠（CMC）在食品工业应用的情况和研究动态．旨在进一步开发CMC新产品和推进食品工业的发展。     

脂肪醇对Triton X—100临界胶团浓度的影响

用环法测定了Ｔｒｉｔｏｎ Ｘ－１００的临界胶团浓度（用ＣＭＣ表示），并探讨不同链长及结构的脂肪醇对Ｔｒｉｔｏｎ Ｘ－１００的ＣＭＣ影响，利用表面化学原理讨论其现象。     

改性PAE树脂的制备及性能研究

采用羧甲基纤维素（CMC）对聚酰胺多胺环氧氯丙烷（PAE）树脂进行改性,以期在保持原有增湿强作用不变的前提下,提高PAE树脂的使用性能,并赋予其一定的增强性能,降低PAE树脂的使用成本。探讨了PAE树脂的改性工艺,并对改性PAE树脂进行傅里叶红外光谱表征,研究了改性PAE树脂对纸张的增强效果及对浆料Zeta电位、滤水性能的影响。结果表明,在PAE树脂成品中引入9%的CMC为最优改性工艺;在此工艺条件下制备的改性PAE树脂用量为0.6%时,浆料的滤水性能最优;在相同用量下（0.6%）,与传统PAE树脂相比,添加改性PAE树脂所抄纸张的抗张指数提高约22%,湿抗张指数提高约19%,耐折度提高约13%,撕裂指数提高约5%,内结合强度提高约6%。     

一种新颖的松香酰基甘氨酸型两性双子表面活性剂的合成及性能分析

以酸值为170.54 mg(KOH)/g的松香酸为原料,经酰化、成盐等化学反应制备了以乙二胺为联结基的松香酰基甘氨酸型两性双子表面活性剂,采用傅里叶变换红外光谱仪确证目标产物的基本结构,通过表面张力仪等方法对产物进行性能分析,结果表明,双子表面活性剂的临界胶束浓度(CMC)为5×10-4mol/L,γCMC为34.208 mN/m;乳化时间为2.5 h,乳化力很强,可作为较优的乳化剂;由泡沫力分析可知产物的泡沫性能稳定,泡沫力强。     

Coalescence of bubbles and stability of foams in aqueous solutions of Tween surfactants

Coalescence of air bubbles and stability of foams in aqueous solutions of Tween 20, 40, 60 and 80 are reported in this work. Adsorption of the surfactants at air–water interface was studied by measuring the surface tension of the surfactant solutions. The surface tension profiles were fitted using a surface equation of state derived from the Gibbs and Langmuir adsorption equations. The critical micelle concentration and surface tension at this concentration were determined. The effect of surfactant concentration on coalescence of air bubbles at flat air–water interface was studied. The role of steric force on coalescence time was investigated. The coalescence time distributions were fitted by the stochastic model. The mean values of the distributions were compared with the predictions of seven film-drainage models. Stability of foams was analyzed by the Ross–Miles test. The initial and residual foam heights were measured at different surfactant concentrations. The stability of foams was compared with the coalescence time of the bubbles.     

聚合单体对乳化剂临界胶束浓度和表面张力的影响

对十二烷基硫酸钠(SDS)在不同单体存在下的临界胶束浓度(CMC)和表面张力进行了测定.结果表明:加入亲水单体丙烯酸(AA)可使其CMC值明显降低,加入甲基丙烯酸-β-羟乙酯(HEMA)则使CMC升高,同时加入少量AA和HEMA时也使SDS的CMC降低;加入油溶性单体苯乙烯对SDS的CMC值影响不大.加入亲水单体AA或...     

硫酸盐型孪连表面活性剂的界面性能研究

考察了自制的三种高纯度双直链烷基硫酸盐型孪连表面活性剂的界面性能和驱油性能。结果表明,双直链烷基硫酸盐型孪连表面活性剂的CMC在10-5~10-6mol/L之间;随着表面活性剂浓度的增加,界面张力达到平衡时所需要的时间明显延长;随着联接基团碳链长度的增加,油水界面张力先增大再减小;此类孪连表面活性剂具有非常好的抗一价盐二价盐的能力;用2C13-C2-2C2SO4Na作为驱油剂进行驱油实验时,可以使采收率在水驱基础上提高5%以上,具有比较好的驱油效果。     

Physical properties and antimicrobial activity of chilled meat pads containing sodium carboxymethyl cellulose

An improved chilled meat pad consisting of nonwoven fabric containing essential oils or active powders, coated by a sodium carboxymethylcellulose (CMCNa) layer was prepared successfully. In the formation of CMCNa film, effects of four acids and pH were examined to obtain optimal results in terms of water, saline, and simulative blood sorption. Fourier Transform Infrared spectroscopy, scanning electron microscopy, and differential scanning calorimetry were used to evaluate the CMCNa film. Also, antimicrobial activities were examined in relation to water loss, aerobic bacterial count, and pH. When the pH value was 4.6 adjusted by citric acid, CMCNa film had the largest absorbent capacity. In the first 6 days, pads with essential oils were superior to pads with powders but inhibiting effect decreased with essential oil releasing. The pad with clove powder gained the best inhibiting effect and could extend the shelf life of chilled meat to 10 days. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

A Corrosion Inhibition Study of a Novel Synthesized Gemini Nonionic Surfactant for Carbon Steel in 1 M HCl Solution

In this study, a gemini nonionic surfactant was synthesized as a corrosion inhibitor for carbon steel in 1 M HCl. Surface properties of the synthesized gemini nonionic surfactant were determined by using surface tension. The results showed that the gemini nonionic surfactant has good surface active properties. The corrosion inhibition effect of the synthesized inhibitor on carbon steel was evaluated by using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization and weight loss methods. The characterization of the film formed on the steel surface was carried out by scanning electron microscope (SEM) methods. The inhibitor molecules were adsorbed physically onto a carbon steel surface according to the Langmuir adsorption isotherm. The results revealed that the inhibitor acted as a mixed-type inhibitor. It was found that the inhibition efficiency increases with an increase in inhibitor concentration and decreases with increasing temperature. Thermodynamic parameters were calculated to elucidate the inhibitive mechanism.