疏水改性核壳结构颗粒对Pickering乳液的稳定作用

为了探究固体颗粒对乳液的稳定作用,采用双亲染料分子罗丹明B对核壳结构的Fe_3O_4@SiO_2纳米颗粒进行疏水改性,并将改性后的纳米颗粒作为稳定剂制备Pickering乳液。通过Zeta电位、FTIR、XRD、SEM、接触角测量、光学显微镜、电导率仪对Fe_3O_4@SiO_2纳米颗粒以及Pickering乳液的结构、形貌和性能进行表征与分析,结果表明:制备的纳米颗粒粒径小,约为150 nm,为单分散球形核壳结构;罗丹明B成功修饰到Fe_3O_4@SiO_2纳米颗粒表面,改性后颗粒接触角由30°增加至120°;随乳化剂颗粒质量浓度的增加,制备的乳液液滴的粒径减小。另外,所得Pickering乳液具有良好的磁场响应性,可通过外加磁场实现对乳液稳定性的可逆调控,且此过程可重复3次以上。     

Hydrophobic Nano‐Silica for the Surface Modification of Graphite Flake

Graphite flake is an electromagnetic interference material of importance for IR screening. In this study, an attempt to improve the performance of graphite flake by coating it with nano‐silica using cyclomix (Hosokawa) and hybridizer (Nara) processes was made. Uncoated and coated graphite flakes were examined by scanning electron microscopy (SEM). It was shown that a more uniform coating was obtained using the hybridizer process. Coated graphite flake with a mass ratio of nano‐silica equal to 5.25 % exhibited the best hydrophobic properties. The test chamber experiments demonstrated that the deposition velocity of coated graphite flake decreased from 0.227 cm s⁻¹ to 0.187 cm s⁻¹ and its IR interference performance was improved, compared with uncoated graphite flake. The obtained results showed that the coatings on the graphite flake powder with hydrophobic nano‐silica enhanced the moisture resistance and electromagnetic interference performance of the graphite flake.     

Hydrophobic Modification and Regeneration of Shirasu Porous Glass Membranes on Membrane Emulsification Performance

The effect of hydrophobic modification and regeneration of Shirasu porous glass (SPG) membranes was systematically investigated on the monodispersity of emulsions. The results showed that the hydrophobic modification and regeneration of SPG membranes had little influence on the monodispersity of emulsions, no matter how many modification and regeneration runs were operated. The emulsification runs affected the emulsification performance to a certain extent when hydrophobically‐modified SPG membranes were used for preparing water‐in‐oil (W/O) emulsions repeatedly. However, they almost did not affect the emulsification performance when regenerated hydrophilic SPG membranes were used for preparing oil‐in‐water (O/W) emulsions. The SPG membranes could be used repeatedly after hydrophobic modification or regeneration with almost the same emulsification performance as fresh or freshly‐modified ones. The results provided some valuable guidance for the repetitive use of SPG membranes to prepare monodisperse O/W and W/O emulsions.     

疏水性沸石分子筛的特性及表面改性研究

介绍了疏水性沸石分子筛的疏水机理、吸附特性和表面改性技术 ,探讨了这一技术用于二氧化碳控制技术的发展前景     

分子筛疏水改性对CO2吸收强化的影响

Two methods of the modification of zeolite were employed:framework element modification and surface coating,and the influence of the zeolites before and after modification on the CO₂ absorption was investigated.It was found that although hydrophobicity of zeolite could be obtained by means of the surficial organic coating in the method of surface coating modification,partial channel of zeolite would be plugged,as a result,leading to the surface area reducing greatly.Distinctively,the framework element modification method could maintain not only complete lattice structure and adsorption capability of zeolite,but would also obtain a good hydrophobic property.Consequently,significant enhancement on gas absorption by this modified zeolite was achieved and up to a maxi-mum enhancement factor of 2.62.This shows that the solid particles with good enhancement role to gas absorption need not only good adsorptive capability but also certain hydrophobicity.An unsteady heterogeneous model was employed to predict enhancement factor and the calculated results agree well with the experimental data.     

化学剂组分浓度对聚合物凝胶成胶性能影响研究

为了更好的揭示聚合物凝胶体系的成胶规律,利用布氏粘度仪对不同化学剂浓度下聚合物凝胶体系成胶粘度及成胶时间进行表征。研究结果表明:凝胶体系随着聚合物以及铬交联剂浓度的增加成胶时间下降、成胶强度增加,硫脲作为稳定可以有效的延缓成胶时间而对成胶强度影响较小。综合考虑成胶时间及成胶强度,最佳的聚合物凝胶体系配方为浓度为2 500 mg/L的聚合物+质量分数为为0.3%的铬交联剂醋酸铬+质量分数分别为0.03%的硫脲。     

SDS／C16 mimBr复配中相微乳液的增溶性能研究

运用δ-γ"鱼状"相图法,以SDS-C16mimBr/正丁醇/正辛烷/2.5% NaCl水溶液四元体系微乳液为例,研究了十二烷基硫酸钠(SDS)与离子液体表面活性剂溴代1-十六烷基-3-甲基咪唑(C16mimBr)复配体系的增溶性能.     

纳米二氧化硅的疏水改性及其对Pickering乳液的稳定作用

为了探究固体粒子对乳液的稳定作用,采用L-赖氨酸作为催化剂合成纳米SiO2粒子,并用六甲基二硅胺烷(HMDS)对纳米SiO2粒子进行表面疏水改性,将经过HMDS改性后的纳米SiO2粒子作为稳定剂制备出Pickering乳液。通过粒径分析仪、场发射透射电子显微镜、FTIR、TG-DSC、接触角测量仪、光学显微镜、电导率仪分别对纳米SiO2的制备、表面改性和Pickering乳液的性能进行了表征。结果表明,成功合成出粒径小且形貌均一的硅球,具有疏水性的三甲基硅基成功接枝到纳米SiO2的表面;不同纳米SiO2浓度制备的Pickering乳液,发现随着SiO2浓度的增大,乳液的稳定性逐渐增强,乳液液滴直径呈现减小的趋势;不同油水比制备的Pickering乳液,发现随着油相体积的增大,乳液的稳定性呈现增大的趋势。     

掺杂改性对聚苯乙烯性能影响的研究

文章阐述了掺杂烷氧金属的聚苯乙烯的制备以及用红外光谱、扫描电镜和热分析分析其微观结构和热性能的部分研究结果。     

乙醇对HIPEs法制备吸油憎水树脂及其性能的影响

以苯乙烯、二乙烯基苯为共聚单体,过硫酸铵为引发剂,十六烷基三甲基溴化铵为乳化剂,采用油包水型高内相比乳液模板法合成了聚苯乙烯/二乙烯基苯(PSD)多孔树脂。考察了相对于分散相不同体积分数的乙醇对乳液稳定性及PSD的密度、吸(释)液性、溶胀率等性能的影响。发现随着乙醇用量的增加,反应体系难以形成稳定的乳液,其密度、吸液性、溶胀性下降,而对甲苯的释放速率增加;PSD多孔材料经水-乙醇抽提后吸水率降低至0.26 cm3/g,而吸甲苯率仍达15.60~18.42 cm3/g,表现出明显的吸油憎水性能。     

Effect of solubilized amines on the structural transition of cetyltrimethylammonium bromide micelles in aqueous potassium bromide

Rod-shaped micelles were produced by mixing 0.1 M cetyltrimethylammonium bromide (CTAB) and 0.1 M KBr in aqueous solution. The effects of the addition of aliphaticn-amines (C₄, C₆, C₇ and C₈) and temperature on the shape of micelles were studied by viscosity measurements. The viscosity data show that transition of rod-shaped micelles to larger aggregates is induced by addition of higher amines (≥C₆) up to a certain concentration; a further increase in concentration produced the opposite effect. Addition of C₄-amine induces only a rod-to-sphere transition. The data were interpreted in terms of solubilization/incorporation (decrease of micellar surface charge density) of amines inside the micelles and the nature of the effective solvent (water+amine). The latter effect dominated the change from larger aggregates to smaller micelles at higher concentrations of the added amine. Increasing the temperature produced effects similar to C₄-amine addition, namely, rod-to-sphere transition. Activation free energy (ΔG^*) and enthalpy (ΔH^*) were also computed from the temperature dependence of the viscosity. ΔG^* and ΔH^* values were higher for larger aggregates (long rods) than for smaller ones (spherical micelles) and ΔH^* covered almost the total contribution to ΔG^*.     

改性胶粘剂对芳纶单向布防弹性能的影响

通过物理共混的方法,将固化剂及消泡剂加入到丙烯酸酯胶粘剂中,从而改善丙烯酸酯胶粘剂压合的单向（UD）芳纶布表面粘手及不平整的问题,并利用电子拉力实验机对无纬布进行力学性能测试。研究表明,固化剂的添加可明显提高UD布的粘结强度,并且UD布的表面不粘手;消泡剂的添加能够明显改善UD布的表观质量,UD布表面平整和无气泡;添加固化剂可提高UD布的力学性能,同时还可提高了材料的防弹性能,子弹穿透层数减少,UD布的平均弹坑凹陷深度明显降低,减少了对人体造成的钝伤。     

表面改性对活性炭吸附性能的影响

采用浓硝酸对活性炭进行表面氧化处理,将得到的样品分别浸渍在银氨、硫酸铜及咪唑溶液中进一步改性,然后采用Boehm滴定法对改性活性炭表面酸性基团的含量进行测定,研究改性对活性炭吸附性能的影响。结果表明：通过上述改性,活性炭表面酸性基团发生了显著变化,特别是羧基含量增加较多,从而活性诙的吸附性能发生了相应的变化。     

硅铝胶改性膨润土的性能研究

本文制备了硅铝胶改性的膨润土和硅铝胶 十六烷基三甲铵复合改性膨润土。研究了硅铝胶改性对膨润土的重金属离子吸附性能和在水介质中的沉降性能的影响 ,以及对有机膨润土吸附极性有机毒物能力的影响 ,并用XRD、IR对改性土进行了分析。结果表明 :硅铝胶改性在膨润土端面发生 ,改性能显著提高膨润土吸附钴离子能力 ,改善其沉降性能 ;硅铝胶的存在增大了有机膨润土对水溶液中有机物的吸附选择性     

纤维改性对小麦秸秆纤维/PBS复合材料性能的影响

利用NaOH对小麦秸秆纤维进行处理,同时采用了不同的蒸煮助剂和改性剂,以改变纤维自身物理性能及其表面化学性质。将改性纤维与聚丁二酸丁二醇酯(PBS)共混,制备了秸秆纤维/PBS复合材料,并通过X射线能谱仪(EDS)、X射线衍射仪(XRD)和扫描电子显微镜(SEM)对改性前后的纤维进行了分析和观测,研究分析了助剂和改性剂对复合材料性能的影响。结果表明:秸秆纤维经NaOH/4%Na2SO3处理,以及碱处理纤维经钛酸酯偶联剂NDZ201、环氧树脂E44改性,所得纤维增强复合材料的性能较为优异。     

表面改性对滑石粉理化性质的影响

采用钛酸酯对滑石粉进行表面改性,以接触角为评价指标,得到最佳的改性工艺参数为:钛酸酯的添加量为3％,反应温度为65℃,反应时间为1.5h.分别采用粒度分析、XRD分析、红外光谱分析以及热重分析对改性前后滑石粉的结构和表面性质进行表征,结果表明,钛酸酯对滑石粉的改性效果显著,表面改性过程不仅发生了物理吸附,还存在化学键合.     

反应条件对FO-35M催化剂加氢改质性能的影响

针对催化裂化汽油加氢过程辛烷值损失过大的问题,抚顺石化公司开发的FCC汽油加氢改质催化剂(FO-35M)具有降烯烃最大限度减少辛烷值损失作用。以某炼厂提供的FCC汽油中间馏分为原料,考察不同反应条件对该剂加氢改质性能的影响。结果表明反应温度、压力对FO-35M催化剂加氢改质性能影响显著,存在最佳范围;而空速对降烯烃有一定影响,氢油比影响最弱。在工业装置运行过程中,要综合考虑各种因素,选择适宜的反应温度、压力、空速,保证装置的长周期运行。     

聚丙烯酸酯共混改性水性聚氨酯乳液的性能研究

自制了水性聚氨酯乳液,并采用共混方法制备了丙烯酸酯改性水性聚氨酯乳液。研究了共混膜的结构和性能,结果表明共混改性的涂膜性能比水性聚氨酯乳液涂膜性能有明显的提高。     

凹凸棒土表面改性及其对聚丙烯力学性能的影响

使用硬脂酸钠、硅烷和钛酸酯偶联剂对凹凸棒土进行了表面改性,通过熔融共混法制备PP/凹凸棒土复合材料。借助FTIR、DSC、TEM、材料力学实验机等手段分别对凹凸棒土的改性效果、分散状态以及复合材料的结构与性能进行了研究。结果表明,适当的表面修饰有助于凹凸棒土在PP基体中实现以针状棒晶为基本形态的均匀分散;凹凸棒土在基体中提高了PP结晶度的同时提高了材料的强度和模量。     

化学改性对聚丙烯腈纤维及预氧纤维结构性能的影响

对聚丙烯腈纤维进行了化学改性,借助差示扫描量热分析（DSC）、定量傅立叶红外光谱（FT-IR）、平衡含水率、密度、力学性能等分析方法,对比研究了改性纤维、预氧化纤维、碳纤维与未改性纤维的结构性能的变化。研究表明：化学改性可促使聚丙烯腈纤维较未改性纤维初始环化反应温度前移,终止温度后移,从而有效缓解纤维在预氧化过程中的集中放热,有利于纤维结构和质量的控制;经硫酸羟胺改性后的纤维较未改性纤维制得的碳纤维抗拉伸强度提高16.3％。