添加剂/超细包覆分散染料液滴形成的影响因素

以苯乙烯-马来酸共聚物为壁材,采用相分离技术对分散染料蓝60进行包覆,制备超细包覆分散染料。探讨了甘油、吐温80用量对超细分散染料胶体性质的影响,在选择合适的黏度、表面张力和一定稳定性的基础上,进而分析了影响液滴形成的因素。红外光谱和透射电镜测试结果表明本研究成功制备了超细包覆分散染料。胶体性质研究表明超细分散染料和甘油的的用量越多,体系黏度越大,吐温80可降低体系表面张力,而三者均会影响体系的稳定性。分析液滴形成过程发现黏度增加,表面张力减少,液滴更容易分离,而且表面张力越小,液滴形成的最大体积越小,黏度是影响“卫星液滴”形成和滴落的主要因素,黏度较低时,“卫星液滴”较易形成,且不易与主液滴重合。     

蛋白质溶液表面张力及其与功能性质的关系

为了探讨蛋白质溶液表面张力的变化规律，本文利用表面张力计和食品流变学方法系统地研究了蛋白质溶液表面张力随液滴停留时间的变化及其与功能性质的关系。结果表明：高浓度时，液滴停留时间与表面张力的变化遵循下列一次方程In[（θt-θe）/（θw-θe）]=-kt。对同一蛋白质来说，k值随浓度的增加而增大。蛋白质起泡力与k值呈极显著的线性关系，泡沫稳定性与k值呈正相关。蛋白质的乳化性低浓度时与表面张力呈正相关；高浓度时，乳化性与k值呈正相关。     

基于毛细不稳定性的聚焦通道微液滴操控研究

针对目前利用微流道产生微液滴时,存在的制作成本高、难于控制液滴大小的缺点,采用数值模拟的方法对聚焦通道进行研究。文章基于毛细不稳定性来系统研究聚焦流道液滴生成与作用规律。研究中主要采用水平集方法,探讨了连续相速度、表面张力、两相黏度比、通道尺寸等因素对于液滴生成的影响,并从不稳定性角度来阐释其物理机制。研究结果表明水平集方法可以很好地模拟液滴破碎,发现连续相速度、表面张力、两相黏度比对液滴尺寸影响较大。     

纳米包覆颜料多相流体的喷墨行为

以纳米包覆颜料为着色剂,探讨了共聚单体、表面活性剂、保湿剂、喷射电压和波形对墨滴形态、墨滴拉伸长度、断裂时间、液滴飞行速度、斜喷角度和卫星点等喷墨行为的影响。结果表明表面张力越小液滴越容易离开喷嘴,形成柱状细线,产生卫星点;保湿剂和共聚单体用量越多,黏度越大,主液滴速度越小,可有效减少卫星点;喷射电压在一定范围内,卫星点能追上主液滴;相同物理性质的液滴在不同波形下的喷射性能也不一样,可以选择不同的波形来提高打印流畅性。另外,低表面张力和高黏度可以减小斜喷角度,增加卫星点追上主液滴的概率。     

淀粉浆液表面能对浆纱粘附力的影响

探讨变性淀粉表面能对浆纱粘附力的影响。通过对几种变性淀粉浆液表面张力和浆液液滴在纱片上接触角的测试,分析评价它们对纯棉、涤棉粗纱的粘附性能,进而探讨浆液表面能与浆纱粘附力之间的关系。试验结果表明：表面张力越小,接触角越小,亦即表面能越低,粘附力越大;表面张力越大,接触角越大,亦即表面能越高,粘附力越小;降低表面张力,可提高变性淀粉浆液对纯棉品种、涤棉品种的适应性。     

十二烷基硫酸钠和乙醇对明胶超细纤维成型的影响

通过添加表面活性剂十二烷基硫酸钠(SDS)、乙醇改善较低质量分数(13%)明胶水溶液的静电纺丝成型性能,发现SDS在降低明胶溶液表面张力的同时,提高了溶液的电导率及黏度。当SDS质量分数在0.5%以上时,电纺明胶纤维毡中的串珠消失;溶剂中水/乙醇为95/5(质量比)时,获得的明胶超细纤维毡中串珠减少且纤维直径变细。     

单丝纤维与液滴接触角的两种算法

利用液滴表面张力的Laplace平衡方程导出关系式cosθ=K(1-sinχ)+(1+sinχ)/4K,在测出K,χ后可直接求出接触角θ。再设K,L已知建立以θ为未知量的积分方程,并给出数值解法和计算实例。     

2-丙基庚醇聚氧丙烯聚氧乙烯醚硫酸盐的性能

研究了Extended表面活性剂2-丙基庚醇聚氧丙烯聚氧乙烯醚硫酸盐(C₁₀P_mE₂S,m=3、8、12)的各项物化性能,包括平衡表面张力、动态表面张力、泡沫性能、接触角、润湿及乳化性能,探究了PO基团数目对C₁₀P_mE₂S性能的影响。结果表明：随着PO基团数目的增加,临界胶束浓度cmc减小,cmc时的表面张力升高,动态表面张力降低速度提升,接触角减小,泡沫体积降低,润湿时间延长,乳化性能增强。     

单液滴干燥过程中阿拉伯胶乳液的干燥特性

喷雾干燥塔是一个完全封闭的设施,难以对干燥过程中的液滴取样分析。本试验以阿拉伯胶包埋油脂的水包油(O/W)型乳液为样液,采用单液滴干燥技术(SDD)模拟喷雾干燥条件,通过分析乳液液滴在干燥过程中的形态收缩和干燥动力学参数的变化,探究干燥气流速度和乳液中固形物含量对颗粒的表面形成机制的影响。结果表明,在0.70,0.90,1.10 m/s 3种干燥气流速度下乳液液滴的干燥行为差异很大。在1.10 m/s的干燥气流速度下,液滴水分蒸发最快,表壳形成最早,最终所得颗粒收缩率最小。乳液总固形物含量对液滴干燥行为的影响也较为明显。随着总固形物含量的增高,乳液液滴水分蒸发越慢,表壳形成越早,最终所得干燥颗粒形态越大。本试验对于干燥动力学模型的研究和喷雾干燥产品品质的改善具有指导性意义。     

Oleosin蛋白和磷脂酰胆碱相互作用对重组油体乳液稳定性的影响

研究Oleosin蛋白(OL)与磷脂酰胆碱(phosphatidyl choline,PC)的复合比例及相互作用对重组油体乳液稳定性的影响,对不同样品分别进行乳化性、荧光光谱、动态激光散射、浊度、接触角及贮藏稳定性的测定,并采用光学显微镜对乳液中液滴分布及微观结构变化进行观察。结果表明:当OL/PC=1.5时,乳液的粒径分布均匀,且乳化性最佳(乳化活性指数33.11 m~2/g,乳化稳定性74.22 min),同时乳液的表面张力及贮藏稳定性也最好,通过荧光光谱分析得出此时OL与PC二者结合最为充分紧密。但随着OL添加量的增加,OL与PC在油-水界面处发生竞争吸附,导致乳化能力及稳定性的降低,并通过光学显微镜观测乳液出现不规则非球形液滴。结果说明,在制备重组油体乳液的过程中OL与PC存在最适配比,适宜的比例会促进与OL-PC的相互作用,增强乳液稳定性,本实验得出结论OL/PC=1.5即为最佳配比。     

Biobased surfactant-like molecules from organic wastes: the effect of waste composition and composting process on surfactant properties and on the ability to solubilize Tetrachloroethene (PCE)

In this work, four surfactant-like humic acids (HAs) obtained from garden lignocellulose wastes and kitchen food wastes mixed with garden-lignocellulose wastes, both before and after composting, were tested for surfactant properties and the ability to solubilize tetrachloroethene (PCE). The waste-derived HAs showed good surfactant properties, lowering the water surface tension from 74 mN m(-1) to 45.4 +/- 4.4 mN m(-1), with a critical micelle concentration (CMC) of 1.54 +/- 1.68 g L(-1), which is lower than many synthetic ionic surfactants. CMC was affected by both waste origin and composting processes. The addition of food waste and composting reduced CMC by adding alkyl-C (measured by CP MAS 13C NMR) and N- and S-HA contents (amide molecules), so that a multistep regression was found [CMC = 24.6 - 0.189 alkyl C - 2.64 (N + S); R2 = 0.77, P < 0.10, n = 6]. The four HAs solubilized PCE at the rate of 0.18-0.47 g PCE/g aqueous biosurfactant. These results were much higher than those reported in the literature for a commercial HA (0.026 g/g), but they were in line with those measured in this work for nonionic surfactants such as Tween-80 (0.69 g/g) and Triton X-100 (1.08 g/g).     

Interfacial activity of phenolic-rich extracts from avocado fruit waste: Influence on the colloidal and oxidative stability of emulsions and nanoemulsions

The effects of phenolic-rich extracts from avocado peels (AP) and seeds (AS) on the colloidal and the lipid oxidative stability of oil-in-water (O/W) emulsions/nanoemulsions were evaluated. For this purpose, the interfacial tension (IFT) of avocado oil droplets in the presence of extracts and surfactants (low methoxyl pectin, LMP; Tween 80, T80), individually or combined, was assessed. Individually, T80 led to the lowest IFT values (4.25 ± 0.02 mN/m), followed by AS and AP extracts (9.27 ± 0.86 mN/m and 12.31 ± 0.10 mN/m, respectively) and LMP (14.88 ± 0.05 mN/m). Regarding particle size, the emulsions containing AP and AS extracts were smaller (1.45 ± 0.10 μm and 1.11 ± 0.03 μm, respectively), and stabler, than blank emulsions (4.05 ± 0.51 μm). Conversely, the extracts, especially AS extract, reduced the stability of nanoemulsions causing a 24-fold particle size increase. Nevertheless, AP and AS extracts reduced the formation of secondary oxidation products in emulsions/nanoemulsions. These findings provide novel insights into the potential use of avocado waste.     

氨基葡萄糖癸酸盐的合成与性能研究

氨基葡萄糖盐酸盐与三乙胺在乙醇-水相条件下生成氨基葡萄糖（GA）,GA再与癸酸反应,合成了一种氨基葡萄糖为反离子的脂肪羧酸盐表面活性剂——氨基葡萄糖癸酸盐（GAD）。采用红外光谱和N元素含量分析对GAD进行了结构表征,并测试了其表面性能。结果表明：25℃下,GAD的临界胶束浓度（CMC）为8.51×10-4mol/L,临界胶束浓度所对应的表面张力（γCMC）为30.1 mN/m,饱和吸附量（Γmax）为4.33×10-10mol/cm2,饱和吸附分子面积（Amin）为0.38 nm2;GAD具有一定的泡沫性能,并对液体石蜡具有较好的乳化能力;与Tween 80、十二烷基二甲基甜菜碱（BS-12）和十六烷基三甲基氯化铵（1631）等助剂配伍良好,无分层现象。     

脂肽类生物表面活性剂Surfactin的乳化性

采用白金板法对Surfactin的表面活性进行研究,并用浊度法和离心法对其乳化性进行研究。结果表明：Surfactin的临界胶束浓度为9.03×10－5 mol/L,可将水的表面张力由73.98 mN/m降至最低27.48 mN/m。在浓度为1×10－3～1.2×10－2 mol/L的NaCl溶液中,Surfactin溶液的表面张力随盐浓度升高逐渐降低并最终稳定在34 mN/m;Surfactin在121 ℃处理20 min后,其表面张力仍能保持在37.10 mN/m;在pH值为2～12范围内,其表面活性稳定并良好;表明Surfactin具有较强的NaCl浓度、温度、pH值的耐受性。浊度法测得Surfactin亲水亲油平衡（hydrophilelipophilic balance,HLB）值为14,对所需HLB值为12～16的油相乳化性能良好。     

EFFECT OF EMULSION DROPLETS ON THE RHEOLOGY OF WHEY PROTEIN ISOLATE GELS

The effects of droplet size and emulsifier type on the rheology of whey protein isolate (WPI) gels containing emulsion droplets was studied. Gels were prepared by dispersing droplets of corn oil (20 wt%, d₃₂= 0.7 – 4 μm) in a 10 wt% WPI solution (pH 7.0, 50 mM NaCl), and heating at 90C for 15 min. Gel strength was determined by measuring the stress of gels at 20% compression using an Instron Universal Testing Machine. Droplets stabilized by WPI increased the gel strength, those stabilized by non-ionic surfactants (Tween 20 and Triton X-100) decreased it slightly, and those stabilized by SDS decreased it drastically. Gel strength increased as the droplet size decreased for droplets stabilized by WPI, but was relatively insensitive to the size of droplets stabilized by the small molecule surfactants. These observations may be explained in terms of the interactions between the emulsifiers and the protein network. Droplets coated with emulsifiers which can be incorporated into the protein network reinforce the structure and so increase gel strength, whereas droplets coated with emulsifiers which cannot be incorporated into the protein network disrupt the three dimensional structure of the gel and decrease its strength.     

Preparation of Aminated Lignin through Etherification and Amination

A new method for the preparation of aminated lignin(AEL) through etherification and amination reaction was presented. Chlorine atoms were firstly introduced into lignin through its etherification with epichlorohydrin. Then, hydrophilic amine groups were grafted to the modified lignin structure through amination with ethylenediamine to obtain AEL. Subsequent acidification of AEL led to the ionized aminated lignin(IAEL). The results of our analyses showed that the nitrogen content of AEL was 6.9%. Foaming and emulsifying experiments indicated that AEL had better foamability and emulsifying properties than IAEL. Surface tension tests showed that AEL and IAEL had similar critical micelle concentration(CMC). However, IAEL had lower surface tension(36.33 mN/m) than AEL(42.89 mN/m) at CMC. These results demonstrate the promising applicability of AEL as an emulsifier and that of IAEL as feedstock in the production of detergent and dispersant.     

影响农药雾滴在烟叶上沉积的关键因子分析

为明确农药雾滴在成熟期烟草叶片上有效沉积的关键影响因子,提高病害的防控效果和减少农药污染,利用Canny边缘检测、Zisman和微量称重检测等方法分别测定了成熟期烟草叶片的临界表面张力、不同叶倾角与喷雾距离下的流失点（Point of Runoff, POR）和最大稳定持留量（Maximum Retention, R_m）。结果表明:①药液表面张力与接触角的余弦值呈显著负相关,烟草（红花大金元）叶片的临界表面张力较小,为31.44 mN/m。②上部叶倾角大,集中在60°~70°之间;下部叶倾角小,集中在20°~40°之间;中部叶居中,集中在50°~60°之间。③流失点与最大稳定持流量受叶倾角和喷雾距离影响。不同叶倾角的流失点相差较大,可达30%~43%,流失点与叶倾角呈显著负相关。20°~30°倾角的叶片在喷雾距离为50 cm时的流失点最高,平均为28.0 μL/cm2,比其他距离的处理高约50%;喷雾距离大于100 cm时,流失点和最大稳定持留量变化不大。40°~70°倾角的叶片流失点和最大稳定持留量在不同喷雾距离下基本保持不变。因此,烟草叶片喷施农药时应添加助剂以降低药液的表面张力至其临界表面张力以下,以增强药液润湿和展布能力;施药时下部叶的喷雾距离>100 cm,中、上部叶的喷雾距离>50 cm;施药量应控制在流失点以内。      

反丁烯二酸蔗糖甲酯的功能特性研究

基于防腐防霉剂的构效关系和乳化剂的分子结构特点，合成了反丁烯二酸蔗糖甲酯。抑菌实验表明：对几种常见微生物，酯化度为5．5的反丁烯二酸蔗糖甲酯的最低抑菌浓度比山梨酸的低而接近于富马酸二甲酯，说明其具有较高的抗菌活性；反丁烯二酸蔗糖甲酯的抗菌半衰期要长于山梨酸和富马酸二甲酯，说明其抗代谢性能好，具有一定的开发应用价值。乳化实验表明：酯化度为5．5的反丁烯二酸蔗糖甲酯的HLB值为6．8、临界胶束浓度为0．7g，L、浓度为0.3％溶液的表面张力为28．5mN/m，都接近于span-80，说明反丁烯二酸蔗糖甲酯具有一定的表面活性。有关反丁烯二酸蔗糖甲酯的抗菌特性及乳化特性在食品、日化及涂料等工业领域的应用有待于进一步研究。     

Structure-forming processes in Ca-induced whey protein isolate cold gelation

The structure-forming process of Ca²⁺-induced whey protein isolate (WPI) gels was studied, at 24°C, in the presence of 10 and 120 m CaCl₂. Pre-heating WPI suspensions (10% protein) at 90°C dramatically increased specific viscosity, but did not change the number of accessible sulfhydryl groups, compared to pre-heating at 70°C. The most important factor governing the process appeared to be CaCl₂ concentration, rather than the reactive sulfhydryl groups. At 10 m CaCl₂, the increase in aggregate size and network connectivity over time was achieved by clustering of adjacent aggregates. At 120 m CaCl₂, the increase in aggregate size and connectivity was by enlargement of the aggregates which formed connected paths and filled up interstitial spaces.     

漆脂酰肌氨酸表面活性剂的合成与性能研究

以漆脂为原料,经过硫酸催化水解,生成漆脂脂肪酸,再与氯化亚砜反应生成漆脂脂肪酰氯,然后采用肖顿-鲍曼(Schotten-Baumann)缩合法,在弱碱性条件下,漆脂脂肪酰氯与肌氨酸钠盐进行缩合反应,再经过酸化、萃取等过程,制得漆脂酰肌氨酸。采用红外光谱和核磁共振碳氢谱对其结构进行表征,并对产物钠盐的表面性能进行分析。结果表明,合成产物为漆脂酰肌氨酸,漆脂酰肌氨酸钠盐的临界胶束浓度为6. 733×10~(-4)mol/L,表面张力为22. 845 m N/m,具有较好的表面活性。当漆脂酰肌氨酸钠盐浓度为0. 01 mol/L时,从乳化的液体石蜡中分出10 m L水的时间为90 s,对低极性溶剂的乳化效果较差,但漆脂酰肌氨酸钠盐的起泡和稳泡性能较好,起泡高度为130 mm,5 min后降至115 mm。