两种混合单元混合机理的数值模拟

为了研究SV型和SX型混合单元在全静态乳化器的混合机理,使用群体平衡模型对乳化器内部流场进行模拟分析。结果表明,SV型与SX型混合单元的混合机理是油相与水相材料通过混合单元时其空间流动方向改变,在流场内形成大量的漩涡,从而达到乳化的目的;通过比较流体在经过SV型和SX型混合单元后的水相索特平均直径(d_(32)),得出SV型混合单元的乳化效果更强,但同时消耗更多的能量,压降更大。     

Nano fibrillated cellulose-based foam by Pickering emulsion: Preparation,characterizations, and application as dye adsorbent

An ecofriendly and biodegradable porous structure was prepared from drying aqueous foams based on nano fibrillated cellulose (NFC), extracted from softwood pulp by subcritical water/CO₂ treatment (SC-NFC). The primary aim of this work was to use the modified SC-NFC as stabilizer for a water-based Pickering emulsion which upon drying, yielded porous cellulosic materials, a good dye adsorbent. In order to exploit the carboxymethylated SC-NFC (CMSC-NFC, with a degree of substitution of 0.35 and a charge density of 649 μeqv/g) as a stabilizer for water-based Pickering emulsion in subsequent step, an optimized quantity of octyl amine (30 mg/g of SC-NFC) was added to make them partially hydrophobic. A series of dry foam structures were prepared by varying the concentrations of treated CMSC-NFCs and 4 wt% was found to be the optimum concentration to yield foam with high porosity (99%) and low density (0.038 g/cc) along with high compression strength (0.24 MPa), superior to the conventionally extracted NFC. The foams were applied to capture as high as 98% of methylene blue dyes, making them a potential green candidate for treating industrial effluent. In addition, the dye adsorption kinetics and isotherms were found to be well suited with second order kinetics and Langmuir isotherm models.     

Facile self-assembly approach to construct a novel MXene-decorated nano-sized phase change material emulsion for thermal energy storage

In recent years, phase change material emulsions (PCMEs) with enhanced energy storage capacities and good flow characteristics have drawn significant attention. However, due to the thermodynamically unstable nature and tiny particle confinement, the nanomaterial modification strategies at PCM/water interface to improve stabilities and reduce supercooling of nano-sized PCMEs (NPCMEs) are very limited and challenging. Herein, we report a facile strategy for constructing MXene-decorated NPCME with good stability, little supercooling, and high thermal conductivity by self-assembly of MXene nanosheets at PCM/water interface. The concentrations of MXene have great influences on the average droplet diameters, stabilities, and thermophysical properties of the NPCMEs. The results show that the PCMs have been well dispersed into the water in the form of quasi-spherical droplets, with average droplet diameters of 242–805 nm. The thermal conductivity of 10 wt% n-tetradecane/water NPCME containing 9 mg ml^-1 MXene is 0.693 W m^-1·K^-1, achieving an enhancement by 15.5%, as compared to that of water. Besides, the MXene-decorated paraffin/water NPCMEs exhibit little supercooling and enhanced heat storage capacities. More importantly, this facile self-assembly strategy opens a new platform for preparing high-performance NPCMEs, which can be used as novel heat transfer fluids for thermal energy storage systems.     

均质条件对辛烯基琥珀酸淀粉酯制备的水油乳化体系粒径的影响研究

通过离心法、分光光度计法、电导率法证明了辛烯基琥珀酸淀粉酯具有良好的乳化性和乳化稳定性。以低黏度辛烯基琥珀酸淀粉酯为乳化剂,以大豆油为乳化对象,利用激光粒度仪和光学显微镜探讨了均质转速、均质温度、均质时间、均质pH对辛烯基琥珀酸淀粉酯制备的乳化体系粒径的影响。结果表明:均质pH对乳化体系粒径具有显著的影响;均质时间越长和均质转速越大,乳化体系的粒径越小;均质温度对乳化体系粒径影响较小。     

11-苄硒基十一羧酸铵盐的双重刺激响应性质

合成了一种对氧化还原(Redox)和CO_2/N_2具有双重刺激响应的表面活性剂11-苄硒基十一羧酸铵盐(BSeUA),分别利用傅里叶红外光谱、核磁共振和电喷雾质谱等手段研究了BSeUA在Redox和CO_2/N_2刺激响应前后的分子结构变化特征。结果表明,在过氧化氢和水合肼交替作用下,BSeUA分子中二价硒醚基团(-Se-)与相应的四价硒亚砜基团(-Se=O)之间可以氧化还原可逆互变,在CO_2和N_2交替作用下,BSeUA分子中羧酸根(-COO-)与相应的羧酸(-COOH)之间可以可逆互变,从而实现BSeUA对Redox和CO_2/N_2具有双重刺激响应。分别在Redox和CO_2/N_2刺激作用下,由BSeUA稳定的乳液可以在破乳和再乳化2种状态下开关可逆循环至少5次,且乳液粒径和稳定性未发生明显变化。     

甜菜果胶乳化活性及稳定性

甜菜果胶是一种从甜菜粕中提取的酸性阴离子多糖,主链由鼠李糖和半乳糖醛酸组成,侧链数量丰富,主要由鼠李糖、阿拉伯糖、半乳糖、果糖等一些中性糖组成。其中中性糖末端与蛋白质共价连接,赋予了甜菜果胶良好的乳化性质。本研究主要探究了甜菜果胶的乳化特性并与柑橘果胶进行对比。考察了甜菜粕产地、果胶质量浓度、pH值、温度、贮藏时间等对乳液特性(粒径分布、平均粒径、Zeta-电位和浊度变化)的影响。研究结果表明,产地不同对甜菜果胶结构组成影响较大,以甜菜果胶制备的乳液粒径显著小于柑橘果胶乳液,且乳化活性更高。当甜菜果胶质量浓度为10~25 mg/m L时,乳液在4周的贮存期内保持良好的稳定性,而柑橘果胶乳液粒径显著增加。pH 2~6的范围内,果胶粒径基本保持不变。25~85℃升温过程中,柑橘果胶乳液粒径大幅增加。说明甜菜果胶具有良好的乳化活性和稳定性。本研究为甜菜果胶的实际应用提供了理论指导。     

活性肽-N对D-半乳糖致衰老小鼠的作用效果

为了探讨一种新型抗衰老活性因子——活性肽-N食用后的抗衰老作用,本研究通过给小鼠连续皮下注射D-半乳糖(200 mg/(kg·d),以体质量计,下同)建立衰老模型,造模的同时开始灌胃2.5、25.0、125.0μg/(kg·d)活性肽-N复乳,连续9周。分别采用旷场实验和Morris水迷宫实验检测小鼠的运动探究能力和学习记忆能力。上述行为学实验后,对小鼠血清中谷胱甘肽过氧化物酶(glutathione peroxidase,GSH-Px)活力、丙二醛(malondialdehyde,MDA)含量及脑组织中的乙酰胆碱酯酶(acetyl cholinesterase,ACh E)活力进行测定。结果表明,与衰老模型组相比,活性肽-N复乳高剂量组能显著提高衰老小鼠的运动探究能力,改善其学习记忆能力,提高血清中的GSH-Px活力28.38%(P0.05),降低MDA含量26.19%(P0.05),同时降低脑组织中的ACh E活力23.26%(P0.05)。综合结果表明该活性肽-N对D-半乳糖致衰老小鼠具有明显的抗衰老作用。     

Temperature- and pH-sensitive core–shell nanogels as efficient carriers of doxorubicin with potential application in lung cancer treatment

Temperature- and pH-sensitive core–shell nanogels were prepared by one-pot soapless emulsion polymerization of N-isopropylacrylamide and 2-methacryloyloxy benzoic acid with the aid of a crosslinker (core) using poly(ethylene glycol) methyl ether methacrylate as stabilizer (shell). The size of nanogels depended on the crosslinker used, being considerable smaller (around 100?nm) with the use of the acid-labile crosslinker 9-divinyl-2,4,8,10-tetraoxaspiro[5.5]-undecane (DVA). Doxorubicine (DOX) was loaded in nanogels with good efficiency. The empty nanogels were biocompatible for a lung cancer cell line (NCI-H1437), while the DOX-loaded, DVA-crosslinked nanogels resulted with efficient cytotoxicity for that cell line.     

高温高盐油藏化学驱数值模拟技术进展

针对高温高盐油藏，胜利油田近年来先后研发了非均相体系、乳液表面活性剂体系等新型驱油体系，其驱油机理与传统化学驱油体系有明显的区别，现有商业化数值模拟软件无法有效表征，而自研数值模拟软件存在运算速度慢、难以支撑大规模矿场应用等难题。依托自主知识产权的化学驱数值模拟软件SLCHEM，在室内实验与机理研究基础上，建立了基于粘弹性颗粒孔喉通过系数的非均相复合驱数学模型以及表征乳液表面活性剂乳化增粘特征的数学模型，实现了相应的模拟功能，开展了室内试验的拟合与矿场模型应用，验证了模型的合理性和准确性；综合应用顺序全隐式快速求解算法、并行解法及交替方向解法，实现了百万级规模模型的快速计算。通过概念模型进行了计算效率测试，在网格数100×10⁴、井数116口、生产历史5a条件下，计算速度为2.9h。室内实验验证与矿场实际应用表明，与商业化软件相比，改造后的SLCHEM软件能够实现对新型驱油体系室内实验结果与矿场动态指标的准确拟合，可为化学驱方案优化与动态分析提供有效的技术支持。