刺激响应型Pickering乳液的制备及应用研究进展

固体纳米颗粒代替传统表面活性剂作为乳化剂稳定的Pickering乳液具有高抗聚结性、环境友好性、成本较低等优点,在多种领域具有广阔应用前景。通过适当刺激精确调控乳液稳定性及构建响应型Pickering乳液的研究引起广泛关注。该文详细综述了多种刺激响应型Pickering乳液的构建、调控及其应用。首先阐述了Pickering乳液的稳定性影响因素和备固体颗粒乳化剂表面改性技术;继而介绍了多种刺激响应性Pickering乳液的响应机理和性能;最后综述了Pickering乳液的应用研究;分析展望了Pickering乳液研究应用中存在的问题和发展前景。     

刺激响应型Pickering乳液的制备及应用进展

固体纳米颗粒代替传统表面活性剂作为乳化剂稳定的Pickering乳液具有抗聚结性高、环境友好、成本较低等优点,在多个领域具有广阔应用前景.通过适当刺激精确调控乳液稳定性及构建响应型Pickering乳液的研究引起广泛关注.综述了多种刺激响应型Pickering乳液的构建、调控及应用.首先,阐述了Pickering乳液的...     

基于纤维素纳米晶稳定的亚微米Pickering乳液制备

与传统表面活性剂稳定的乳液相比,固体纳米颗粒稳定的Pickering乳液具有较强的界面稳定性、多功能性、低毒性等优势,在生物医药领域具有较大的应用潜力。而相较于尺寸较大的微米级Pickering乳液,亚微米Pickering乳液具有更大的比表面积、更有效的递送效率,有望进一步拓展Pickering乳液在生物医药领域的应用。但由于Pickering乳液的制备影响因素众多,且相互制约,刚性的固体颗粒难以在较小的有限油水界面排布,增加了亚微米Pickering乳液的制备难度。本工作以制备稳定的亚微米Pickering乳液为研究目标,采用具有良好生物相容性的天然多糖–纤维素纳米晶(CNCs)为颗粒乳化剂,角鲨烯作为油相,考察了颗粒浓度、油水比例、水相成分、超声时间及频率对Pickering乳液粒径分布及稳定性的影响,最终得到了具有良好的储存稳定性和抗离心稳定性的粒径为638.7?8.40 nm的亚微米Pickering乳液(CNCs-PE)。通过激光共聚焦显微镜证实了CNCs吸附在油水界面,形成了Pickering乳液结构。利用CCK-8法评价了CNCs和CNCs-PE的细胞毒性,结果表明,两者都具有良好的细胞安全性。此外,将其用于吸附模型抗原OVA,吸附率达到约80%,且肌肉注射部位的切片结果也表明其注射安全性良好。此结果为亚微米Pickering乳液进一步研究提供了参考,并有望拓展CNCs稳定的亚微米Pickering乳液在生物医药领域的应用。     

生物质颗粒稳定的刺激响应型Pickering乳液

固体颗粒稳定的Pickering乳液在众多领域中发挥着重要的作用,对其在稳定和破乳之间转换具有广泛需求,因此刺激响应型Pickering乳液得以发展。生物质颗粒因其安全性高、适用范围广等优势被应用于稳定Pickering乳液,且近年来关注将其用于稳定刺激响应型Pickering乳液,并显示在食品、药品、化妆品等领域中的应用前景。     

改性二氧化硅颗粒稳定的Pickering乳液及其性质研究

利用碱性基团胍基对气相二氧化硅(SiO_2)进行表面改性,制得了既具有乳化性又具有pH响应性的功能化颗粒SiO_2-G。采用SEM(扫描电镜)、FT-IR(傅里叶变换红外光谱)、TGA(热失重分析)对功能化固体化颗粒SiO_2-G的微观形态、结构和热性能进行了表征,并考察了SiO_2-G掺量、温度和pH等因素对乳液稳定性的影响。研究结果表明:功能化固体颗粒SiO_2-G能够作为颗粒乳化剂稳定大豆油-甲醇两相不相溶体系,形成大豆油/甲醇Pickering乳液;所得乳液具有良好的热稳定性,在70℃下放置300 min都不会发生明显的破乳现象。由于SiO_2-G颗粒表面胍基的酸碱响应性,该Pickering乳液也具有酸碱响应性质,并可实现多次乳化-破乳-乳化循环。     

Pickering乳液的研究进展

简要介绍了Pickering乳液的稳定机理,即机械阻隔机理和三维黏弹粒子网络机理。从球形固体颗粒稳定的乳液、片层状固体粒子稳定的乳液以及不同环境响应型乳液(如pH、温度、电场、磁场)等方面对目前Pickering乳液的研究现状进行了综述,并概述了Pickering乳液在乳液聚合、功能材料的制备、药物释放和催化剂的分离回收等方面的应用研究,最后对其发展方向进行了展望。     

刺激响应性Pickering乳液及其应用研究进展

Pickering乳液具有很多优势,尤以动力学因素赋予的优异稳定性著称.但实际应用中经常只需要体系暂时稳定,而后根据应用过程的需要实现快速破乳或者使乳液类型发生转变.因此,近年来刺激响应性Pickering乳液受到了广泛关注.文章主要从影响乳液性质的颗粒润湿性入手,总结了赋予Pickering乳液以响应行为的常见策略,...     

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。     

纳米Fe3O4稳定的Pickering型ASA乳液

利用纳米Fe₃O₄作为稳定剂和乳化剂来制备Pickering型ASA（alkenyl succinic anhydride） 施胶乳液,并研究了固体颗粒浓度、油水比、水分散相pH对乳液类型、稳定性、形态及施胶性能的影响。结果表明,纳米Fe₃O₄能够乳化制备均一稳定的Pickering型ASA乳液。乳液在室温下静置稳定,析出油相体积分数随固体颗粒用量的增加而增大,随油水比的增大而减小。油水比为2：1,水分散相浓度为0.1%（质量分数）时制备的ASA乳液稳定性最佳。固体颗粒部分吸附在油/水界面处,部分分散在分散相中,随分散相中固体颗粒浓度的增加,乳液稳定性变差。乳液静置分层之前,ASA发生部分水解。在放置1 h后用于纸页浆内施胶,随ASA乳液用量的增加,纸页表面接触角逐渐增大,且纸页表面粗糙度下降。在ASA的添加量为1.0%（质量分数）时,纸页表面接触角达到93.5°,纸页表面粗糙度为15.924 μm。     

SiO_2稳定的Pickering聚合制备PDMS-PBMA共聚乳液

近年来,Pickering乳液引起了研究者的广泛关注,固体颗粒吸附在油滴表面形成Pickering乳液,可以有效地将有机和无机属性结合起来。与传统乳化剂稳定的乳液相比,Pickering乳液可以有效降低乳化剂的用量,节约成本,减少污染,而且乳液稳定性强、体系受温度等影响不大。本文通过二氧化硅稳定的Pickering聚合成功制备了PDMS-PBMA共聚乳液,并研究了单体、二氧化硅及十六烷用量对共聚乳液性能的影响。     

双重刺激响应型pickering乳液研究进展

Pickering乳液因其极强的稳定性、良好的生物相容性和对环境友好等特点在众多领域有着广泛应用.虽然乳液必须具有良好的稳定性,但实际应用中通过适当的触发机制使其能够实现快速破乳也是非常重要的.响应型Pickering乳液由于在特定因素刺激下可以轻易实现可逆乳化-破乳成为近些年研究的热点.早期研究学者主要研究单一刺激因...     

Characteristics of Stable Pickering Emulsions under Process Conditions

Emulsions stabilized by solid particles are so called Pickering emulsions which are characterized by their high stability against coalescence. This type of emulsion can be used for a lot of applications. Very little is known about how reaction conditions affect their properties. In this study the influence of important reaction conditions like shear stress, pressure, temperature, and the influence of synthesis gas on Pickering emulsions is investigated. It is shown that the emulsions remain stable in terms of coalescence in a broad range of the reaction conditions and are suitable as reaction media for industrial processes and for a reaction optimization with a subsequent separation step.     

Double emulsions of water-in-oil-in-water stabilized by α-form fat microcrystals. Part 1: Selection of emulsifiers and fat microcrystalline particles

Double emulsions are commonly stabilized by monomeric and/or polymeric emulsifiers. Pickering stabilization by solid particles such as colloidal microcrystalline cellulose has been mentioned only once as a possible technique to stabilize the external interface of the water-in-oil-in-water emulsion. No further work was carried out exploring this option. The present study shows that solid microcrystalline fat particles of α-form are capable of adsorbing at the water-oil interface and, together with other hydrophobic emulsifiers, can stabilize water-in-oil (W/O) emulsions. The crystals must be submicron in size in order to effectively adsorb and arrange at the interface. Large crystals do not fit and were found to flocculate as free crystals in the continuous oil phase. The α-form crystals can be obtained by flash-cooling saturated triglycerides in vegetable oils in the presence of emulsifiers, such as polyglycerol polyricinoleate (PGPR), that stabilize the dispersion and serve as α-tending crystal structure modifiers. It was assumed that PGPR also serves as a cross-linker or bridge between the crystalline fat particles and the water, and facilitates the anchoring of the fat particles in the oil phase in one direction while dangling itself in the water phase. The double emulsion droplets prepared with these W/O emulsions are relatively large in size (6–18 μm), but stable to coalescence. The marker (NaCl) does not seem to release with time, suggesting that the fat particles form microcapsules on the water interface, totally sealing the water from releasing its addenda. The systems seem to have a significant potential for food emulsions.     

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。     

The effect of hydrodynamic parameters on the production of Pickering emulsions in a baffled stirred tank

Pickering emulsions are potential industrial scale alternatives to surfactant-based emulsions. The stability of Pickering emulsions depends on the physicochemical nature of the liquid–particle interface and the hydrodynamic conditions of the production process. This article investigates the effect of hydrodynamic conditions on the drop size of concentrated Pickering emulsions in baffled stirred tanks. Oil in water emulsions composed of silicon oil, water, and hydrophilic glass beads as stabilizing particles were produced. Two impellers were used at different sizes: Rushton turbine (RT) and pitched blade turbine. The effects of power per mass, Reynolds number, tip speed, and Weber number on the droplet sizes were studied. The energy dissipated around the impeller and the size of the impeller high shear zone were found to be critical to the emulsion droplet sizes. The breakup and droplet-particle contact mechanism of the RT was found to be more favorable for the production of the Pickering emulsions.     

基于纳米氢氧化铝颗粒的Pickering乳液制备

以异丙醇铝为原料,采用醇盐水解?水热法制备勃姆石型纳米氢氧化铝颗粒,优化制备条件;以所制颗粒为稳定剂、角鲨烯为油相,通过超声破碎法制备Pickering乳液,考察了颗粒浓度、水相成分、超声时间及功率对Pickering乳液粒径及稳定性的影响。结果表明,水热温度200℃、水热时间2 h条件下,可制得结晶度高且均一的勃姆石型纳米氢氧化铝颗粒,平均粒径为55.70?9.20 nm,多分散性指数(PDI)为0.187?0.011;所制Pickering乳液平均粒径为1870?55 nm,PDI=0.120?0.010,可在室温下稳定储存120 d以上,且生物相容性良好,有望应用于生物医药领域。     

高亲水性纳米二氧化硅颗粒稳定Pickering乳液

用未修饰的高亲水性纳米二氧化硅颗粒(SiO2 NPs)在其等电点附近制备Pickering乳液。结果表明,等电点(pH 2.7)条件下SiO2 NPs借助高能均质与油水界面剧烈混合,并在范德华引力的驱动下以弱吸附的状态在界面处负载,从而稳定得到O/W型Pickering乳液。增加SiO2 NPs的浓度或减小油相体积分数可提高单位油滴界面的颗粒负载率,增大连续相黏度并促进乳液液滴之间形成三维网络结构从而提高乳液稳定性。通过调节连续相的pH以促进SiO2 NPs表面的硅烷醇发生质子化与去质子化的转变,实现乳液多次pH响应循环。     

Pickering乳化剂在化妆品中的应用

综述了固体颗粒乳化剂的基本作用原理，主要内容包括固体颗粒乳化剂与传统表面活性剂乳化剂乳化性能的不同，固体颗粒乳化剂的作用机理及影响因素，以及固体颗粒乳化剂在化妆品中的应用前景。