Viscoelastic Behavior of Synthesized Liquid Soaps and Surface Activity Properties of Surfactants

In the present work, a rheological study of liquid soaps prepared from different mixture of surfactants as a function of surfactant type and concentration was performed. The curves of shear stress vs. shear rate and viscosity vs. shear rate were recorded at constant temperature, 294 ± 0.1 K. The surface activity properties were also studied. The results of the study showed that values of surface tension, γ, were in the range 31–40 mN m⁻¹ and the critical micelle concentration (CMC), was of the order 10⁻⁴ mol L⁻¹. The calculated maximum surface excess, Γ_max, varied from 2.40 to 3.66 μmol m⁻², while minimum area per molecule, A_min, varied from 41.1 (for amphoterics) to 81.4 Ų (for nonionic surfactants). The standard free energy of micellization, −29.8 and −29.3 kJ mol⁻¹ for anionic and amphoteric surfactants, respectively, were while values for nonionic surfactants varied between −31.8 and − 30.3 kJ mol⁻¹. The free energy of adsorption, was the lowest for amphoteric surfactants (−37.9 kJ mol⁻¹), followed by anionics (−40.4 kJ mol⁻¹) and nonionics (−43.34 to −46.84 kJ mol⁻¹), indicating that micellization process is spontaneous in the examined medium. The synthetized liquid soaps show pseudoplastic behavior and they achieved pipe flow. The results of this research indicate that flow behavior was affected significantly by the ionic charge of the surfactant and the ionic strength of the formulation, suggesting that the flow behavior could be changed by manipulating the choice of the surfactant and salinity. The pH value of all liquid soaps examined were weakly acidic, in the range of 5.0–6.4.     

基于微生物灭活芽孢的矿冶粉尘清洁皂的制备及性能研究

矿冶粉尘给一线工人皮肤健康带来严重威胁。通过添加微生物灭活芽孢于清洁皂中,研究了不同芽孢添加量对清洁皂去污能力的影响,对比了硅藻土、活性炭和芽孢添加皂在粉尘去污和重金属去除方面的异同,并通过感官评价测试了三种皂在皮肤清洁方面的效果。结果表明,添加硅藻土可以达到80%的粉尘去除率。而活性炭尽管比表面积高,但微粒细小同样易于吸附于手掌纹理中,造成二次污染,故去除率最低。在基础皂中添加1%(w/w)灭活芽孢对粉尘污染的去污率达到了95%,二次洗涤可将重金属去除率从90%提高到95%以上。感官评价中,黑色活性炭的吸附作用造成了清洗后的手掌依然不够干净,观感最差;硅藻土皂的清洁效果接近日常家用皂,观感居中;而芽孢皂的清洁效果最明显,观感最佳。     

静态热处理时间对轮毂轴承用复合锂基润滑脂流变特性的影响

为研究轮毂轴承工作过程中的热效应对复合锂基润滑脂流变性能的影响,采用静态热处理方式模拟轮毂轴承内复合锂基润滑脂的受热情况。在150℃下对润滑脂进行不同时间的热处理,并采用旋转流变仪研究各样品的流变特性变化规律。研究结果表明:短时间的静态加热处理后,复合锂基润滑脂胶体分散体系发生物理变化;皂纤维缠结程度先降低然后呈逐渐增加的趋势,出现了一定程度的固化;触变性分析表明复合锂基润滑脂的结构恢复性能随加热时间的延长而逐渐减弱。     

油橄榄透明皂的制作研究

首先用油棕榈核油、棕榈油、椰子油、蓖麻油和玉米油作油脂原料合成了透明皂的皂基,之后又将当地特色植物油——橄榄油作为添加剂制作出来一种新配方的油橄榄透明皂。文中考察了原料配比、皂化时间、皂化温度、油橄榄的加入量对油橄榄透明皂的影响,确定了制作油橄榄透明皂的最佳实验条件。     

窄分布AES在液体洗涤剂中的应用性能研究

研究了常规AE_2S和窄分布AE_2S的理化性能,并对其在餐具洗涤剂和洗衣液等产品中的去污力、泡沫和黏度等应用性能进行了研究。结果表明,窄分布AE_2S具有较高的临界胶束浓度(cmc),表面张力(γ_(cmc))与常规AE_2S相近,但其钙皂分散、抗硬水性能优于常规AE_2S;在餐具洗涤剂配方中,窄分布AE_2S体系的去油率、泡沫和增黏性能优于常规AE_2S;在普通洗衣液和皂基洗衣液配方中,窄分布AE_2S体系对炭黑、蛋白和皮脂污布的综合去污力与常规AE_2S相当,增黏性和泡沫高于常规AE_2S。     

HPLC-DAD analysis of florfenicol and thiamphenicol in medicated feedingstuffs

ABSTRACT

A simple and reliable method using liquid chromatography with diode array detector was developed for the simultaneous determination of florfenicol and thiamphenicol in medicated feed. The analytes were extracted from the minced feed with methanol and ethyl acetate (1:1, v/v). Next, the extract was further cleaned up by dispersive solid phase extraction using anhydrous magnesium sulfate, PSA and C18 sorbents. Finally, 1 mL of extract was evaporated, the residue resuspended in Milli-Q water, and filtered. The method was validated in-house at medicated levels, in the concentration range 10–300 µg/mL (50–1500 mg/kg). Values of <6.5% and <6.0% were found, respectively, for repeatability and within-laboratory reproducibility. The LODs for the two fenicols were 2.4–5.3 mg/kg, while the LOQs were 3.8–5.6 mg/kg. The expanded uncertainty was estimated to be in the range of 10.0–14.5%, depending on the analyte. Recoveries varied from 81.7% to 97.5%. The methodology was applied to the analysis of animal feedingstuffs collected from poultry and pig farms.     

On the response of ballistic soap to one-dimensional shock loading

The effects of projectile penetration into soft tissue are often studied using the tissue simulant ballistic soap. Consequently, a full understanding of the high strain-rate response of ballistic soap is desirable. Using the plate-impact technique, key shock parameters have been measured for impacts in the range 81–968 m/s, allowing derivation of the Hugoniot equation-of-state for soap in the U_S–u_P and σ_X–u_P planes. A polynomial Hugoniot relationship was found in the U_S–u_P plane, with the general form U_S = 1.96 + 2.41u_P − 0.72u_P² (ρ₀ = 1.107 g/cc). Further, embedded lateral manganin stress gauges were employed to interrogate the evolution of lateral stress within the soap. A gradient in lateral stress, whose magnitude increased incrementally with impact stress, was apparent behind the shock for σ_X >1 GPa. It is proposed that at higher values of σ_X, increased compression of hydrocarbon chains acts to increase the materials resistance to shear, a phenomenon consistent with steric hindrance.     

泡沫混凝土的制备及强度影响研究

自行研制了泡沫混凝土的松香皂发泡剂,通过大量试验确定了泡沫混凝的最佳配合比,配制出密度为450kg/m3,强度达到1.3MPa左右的泡沫混凝土。分别对石灰、玻璃纤维、三乙醇胺对增加泡沫混凝土强度影响进行了研究,试验表明三乙醇胺对增加泡沫混凝土强度影响较大。     

微波对天麻鱼头汤营养和安全性影响

为探讨微波加工对药膳鱼汤品质影响,以天麻、鱼头为原料,分别采用微波炉和传统电炖锅加热的方法,研究其水溶性蛋白、游离氨基酸、矿物质、天麻素、嘌呤和感官品质的变化规律。结果表明:微波加热更有利于小分子物质的溶出,如氨基酸、矿物质、天麻素和嘌呤等,微波煲汤中游离氨基酸含量甚至高达电炖锅的1.5倍,对蛋白质等大分子物质的影响较小;在安全性方面,微波200 W小功率的煲汤或者400 W大功率短时间煲汤产生的嘌呤含量均不超过15 mg/L,既符合痛风病人安全需求又改善了鱼汤的风味;在感官评价方面,采用微波炉400 W煲汤1 h的感官得分可以达到与电炖锅煲汤3 h相类似的效果,可以将煮制周期缩短2 h,微波加热可大大缩短煲制时间,是一种更加高效的煲汤方式。     

餐厨废油脂一步合成钙皂

开发了一种利用餐厨废油脂和氧化钙,在双氧水的催化作用下直接合成金属钙皂的环境友好方法。采用单因素试验优化了皂化温度、皂化时间、物料比、油水比和催化剂用量。结果表明,在最佳工艺条件下,即皂化温度90～95℃、皂化时间4. 0～6. 0 h、催化剂(H_2O_2)用量10 m L(50 g餐厨废油脂)、物料比(餐厨废油脂与氧化钙质量比) 50∶7、油水比(质量比) 1∶4. 5时,皂化率达到95%以上。产品为干燥粒状固体,钙含量为7. 31%,游离酸含量为0. 12%,熔点为131～138℃。