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1.
近年来,纳米科技的蓬勃发展将颗粒乳化剂的研究热点从传统乳化领域拓展到纳米材料的制备领域。颗粒乳化剂体系也从最初的无机颗粒拓展到有机/无机复合颗粒乳化剂、聚合物颗粒乳化剂、天然大分子颗粒乳化剂等体系,并引起了科学家们的广泛关注。本文主要对大分子颗粒乳化剂近期研究进展进行了综述,介绍了颗粒乳化剂的基本概念和乳化机理,按化学...  相似文献   

2.
徐丽  游长江  谢青 《广州化学》2008,33(1):54-58
综述了当前环氧树脂增韧增强改性的研究现状,详细介绍了弹性体增韧环氧树脂、无机纳米粒子改性环氧树脂、粘土改性环氧树脂、纳米SiO2改性环氧树脂以及弹性体/无机纳米粒子协同增韧增强环氧树脂的机理和实验方法。并对其实验结果进行了分析比较。  相似文献   

3.
超细金属铁颗粒的高分子修饰及其悬浮液的磁流变性能   总被引:1,自引:0,他引:1  
报道以γ射线辐照方法合成出具有良好分散性的高分子复合金属铁粒子.分别选择十二烷基硫酸钠、溴化十六烷基三甲基铵、Tween-80、TritonX-200和OP-10等表面活性剂和有机单体、无机铁颗粒一起制备乳状液,通过对这种含有超细金属铁颗粒乳状液稳定性的比较,以寻求合适的乳化剂.并对以TritonX-200为乳化剂时合成出的高聚物复合铁颗粒进行了XRD、TEM和IP表征.还将实验中所获得的高聚物复合铁粒子与粒径相同的未经修饰的纯铁粒子分别制成了悬浮液,对两者的悬浮性能进行了比较,同时,也将高聚物复合铁粒子制成的悬浮液与Fe3O4-PMMA复合粒子悬浮液两者的屈服应力随磁场变化情况进行比较研究.  相似文献   

4.
田明 《高分子学报》2001,18(5):639-644
提出了以具有纳米尺寸孔径及孔壁厚度的MCM 48作为无机基体、以无机 有机原位自组装的方法形成纳米网络粒子 .研究结果表明 ,在一定实验条件下 ,有机相可进入无机相的三维孔道自组装形成立方有序结构的纳米网络复合粒子 .通过研究纳米网络粒子在极性介质和非极性介质中的分散发现 ,有机相的存在有利于纳米网络粒子的分散  相似文献   

5.
本文简要介绍了几类纳米粒子的制备及其在打印印刷领域的应用.包括无机纳米粒子复合材料用于绿色打印制版、聚合物乳胶纳米粒子用于喷墨打印制备光子晶体、金属纳米粒子用于印刷电路以及纳米材料用于3D打印,并展望了其发展前景.  相似文献   

6.
无机纳米粒子在复合聚合物电解质中作用的研究进展   总被引:1,自引:0,他引:1  
古宁宇  李超  张荣斌 《化学通报》2007,70(9):677-683
聚合物电解质材料已经成为当前锂离子电池研究领域的热点之一。复合化是有效提高聚合物电解质材料性能的有效手段。本文从纳米粒子掺杂的角度,综述了近年来无机纳米粒子对复合聚合物电解质(CPE)体系的离子电导率、锂离子迁移数的影响,并介绍了四种初步解释了无机纳米粒子在复合聚合物电解质中的作用的机理;讨论了无机纳米粒子对CPE体系/电极界面稳定及相容性的影响;提出了无机纳米粒子掺杂的复合聚合物电解质研究的三个热点方向。  相似文献   

7.
陈梦君  杨万泰  尹梅贞 《化学进展》2012,(12):2403-2414
纳米粒子是当今最受关注也是最常报道的一类纳米材料,尺寸处于纳米级别是纳米粒子的突出特点,这赋予其在化学、光学、电学和磁学等方面优于传统块体材料的独特性能,因而纳米粒子越来越受到人们的重视,并广泛应用于很多领域,尤其是生物医药领域。本文围绕可生物应用的纳米粒子,从组成以及结构的角度着手,将纳米粒子分为有机纳米粒子、无机纳米粒子以及有机/无机杂化纳米粒子。同时结合近三年国内外关于各类纳米粒子新颖的合成报道,分别阐述了上述不同种类纳米粒子所具有的适合生物应用的物理和化学方面的特征,并针对不同类别的新型纳米粒子,着重描述了其具体合成方法和潜在的生物应用。最后,简单介绍了纳米粒子在生命科学这一领域的具体应用实例,如刺激响应感应器、生物特异性标记及基因药物载体等,并展望了纳米粒子在该领域的长远发展。  相似文献   

8.
纳米无机粒子/聚合物复合材料界面结构的研究   总被引:1,自引:0,他引:1  
纳米粒子具有许多特性,聚合物中加入纳米粒子可以制备得到性能更加优异的复合材料,其中纳米粒子和聚合物基体间的界面对决定纳米复合材料的性能起着重要作用.本文综述了近些年来表征纳米无机颗粒/聚合物复合材料中界面结构的研究手段,如红外光谱(FTIR)、热重(TGA)、电子显微镜、小角中子散射(SANS)及小角X射线散射(SAXS)等,及界面结构与复合材料力学性能和热稳定性关系的研究进展.同时也介绍了纳米粒子对复合材料的渗透、光催化、阻燃、介电及导电性能的影响.最后对这一领域的研究进行了展望.  相似文献   

9.
无机纳米粒子在环氧树脂增韧改性中的应用   总被引:8,自引:0,他引:8  
张小华  徐伟箭 《高分子通报》2005,(6):100-104,112
无机纳米粒子能够给聚合物赋以卓越的综合性能,为此,纳米材料在聚合物改性中的应用已成为聚合物改性领域中的一个研究热点。本文就近年来在环氧树脂增韧改性中应用的无机纳米粒子的种类、环氧树脂/无机纳米复合材料的制备方法及其应用研究进展进行了综述。  相似文献   

10.
采用一种简单易行的方法制备了氨基功能化的聚苯乙烯纳米粒子.首先,采用4-乙烯基苄氯与1,3-丙二胺置换反应制备了含有氨基功能基团的可聚合单体N-(3-氨基丙基)对乙烯基苄基亚胺(CVPD).然后,采用乳液聚合,以苯乙烯(St)和CVPD为共聚单体,水溶性的4-(2-羟乙氧基)苯基-(2-羟基-2-丙基)酮(Irgacure 2959)为光引发剂,十六烷基三甲基溴化铵(CTAB)为乳化剂,经紫外光辐照引发,合成了P(St-co-CVPD)二元共聚物的纳米胶乳.体系的乳化剂用量仅为体系总质量的0.1 wt%~0.8 wt%,远小于常用来制备纳米粒子的微乳液体系的乳化剂用量.用透射电子显微镜(TEM)和激光粒度分析仪(DLS)表征了P(St-co-CVPD)纳米粒子的粒径和粒径分布.用红外光谱(FTIR)和核磁共振(NMR)证明了P(St-co-CVPD)纳米粒子上氨基的存在,并通过茚三酮显色反应定量检测了氨基含量.分别研究了单体配比,引发剂浓度,乳化剂用量以及紫外光强度对反应体系的影响.实验结果表明,产物粒子尺寸为30~600 nm,氨基通过共价键连接在粒子上,其含量为1.2×10-5~1.6×10-4 mol/g.该乳液体系聚合反应速率较快,单体转化率在60 min内即可达到80%.所得粒子的氨基含量可以通过单体配比进行调节.粒子尺寸可通过单体配比,引发剂浓度,乳化剂用量以及紫外光强度进行调节.  相似文献   

11.
The versatility of colloidal particles endows the particle stabilized or Pickering emulsions with unique features and can potentially enable the fabrication of a wide variety of derived materials. We review the evolution and breakthroughs in the research on the use of colloidal particles for the stabilization of Pickering emulsions in recent years for the particle categories of inorganic particles, polymer-based particles, and food-grade particles. Moreover, based on the latest works, several emulsions stabilized by the featured particles and their derived functional materials, including enzyme immobilized emulsifiers for interfacial catalysis, 2D colloidal materials stabilized emulsions as templates for porous materials, and Pickering emulsions as adjuvant formulations, are also summarized. Finally, we point out the gaps in the current research on the applications of Pickering emulsions and suggest future directions for the design of particulate stabilizers and preparation methods for Pickering emulsions and their derived materials.  相似文献   

12.
Different from traditional methods for preparing pH-switchable Pickering emulsifiers, a simple and straightforward approach is established on the basis of a reversible process between in situ formation and dissolution of Mg(OH)(2) nanoparticles (MHp). It was found that when pH value was above 9.5, emulsions of liquid paraffin-in-water can be stabilized by the resulting surface-active particles. Below this pH, emulsions demulsify, resulting in a reversible Pickering emulsifier. Based on the strongly pH-dependent precipitation of metal hydroxide nanoparticles, this procedure offers a new way to design pH-switchable emulsifiers without aid of any other organic matters.  相似文献   

13.
Chitosan without hydrophobic modification is not a good emulsifier itself. However, it has a pH-tunable sol-gel transition due to free amino groups along its backbone. In the present work, a simple reversible Pickering emulsion system based on the pH-tunable sol-gel transition of chitosan was developed. At pH > 6.0, as adjusted by NaOH, chitosan was insoluble in water. Chitosan nanoparticles or micrometer-sized floccular precipitates were formed in situ. These chitosan aggregates could adsorb at the interface of oil and water to stabilize the o/w emulsions, so-called Pickering emulsions. At pH < 6.0, as adjusted by HCl, chitosan was soluble in water. Demulsification happened. Four organic solvents (liquid paraffin, n-hexane, toluene, and dichloromethane) were chosen as the oil phase. Reversible emulsions were formed for all four oils. Chitosan-based Pickering emulsions could undergo five cycles of emulsification-demulsification with only a slight increase in the emulsion droplet size. They also had good long-term stability for more than 2 months. Herein, we give an example of chitosan without any hydrophobic modification to act as an effective emulsifier for various oil-water systems. From the results, we have determined that natural polymers with a stimulus-responsive sol-gel transition should be a good particulate emulsifier. The method for in situ formation of pH-responsive Pickering emulsions based on chitosan will open up a new route to the preparation of a wide range of reversible emulsions.  相似文献   

14.
Complex emulsions,such as double emulsions and high-internal-phase emulsions,have shown great applications in the fields of drug delivery,sensing,catalysis,oil-water separation and self-healing materials.Their controllable preparation is at the forefront of interface and material science.Surfactants and polymers have been widely used as emulsifiers for building complex emulsions.Yet some inherent disadvantages exist including multi-step emulsifications and low production efficiency.Alternatively,supramolecular polymer emulsifier for complex emulsions via one-step emulsification is rising as a new strategy due to the ease of preparation.In this feature article,we review our recent progresses in using supramolecular polymer emulsifiers for the preparation of complex emulsions.Double emulsions and high-internal-phase emulsions are successfully prepared via one-step emulsification with the help of different supramolecular interactions including electrostatic,hydrogen bond,coordination interaction and dynamic covalent bond,which will be particularly emphasized in detail.In the end,a comprehensive prospect is given for the future development of this field.This article is expected to provide new inspirations for preparing complex emulsions via supramolecular routes.  相似文献   

15.
The stability and rheology of tricaprylin oil-in-water emulsions containing a mixture of surface-active hydrophilic silica nanoparticles and pure nonionic surfactant molecules are reported and compared with those of emulsions stabilized by each emulsifier alone. The importance of the preparation protocol is highlighted. Addition of particles to a surfactant-stabilized emulsion results in the appearance of a small population of large drops due to coalescence, possibly by bridging of adsorbed particles. Addition of surfactant to a particle-stabilized emulsion surprisingly led to increased coalescence too, although the resistance to creaming increased mainly due to an increase in viscosity. Simultaneous emulsification of particles and surfactant led to synergistic stabilization at intermediate concentrations of surfactant; emulsions completely stable to both creaming and coalescence exist at low overall emulsifier concentration. Using the adsorption isotherm of surfactant on particles and the viscosity and optical density of aqueous particle dispersions, we show that the most stable emulsions are formed from dispersions of flocculated, partially hydrophobic particles. From equilibrium contact angle and oil-water interfacial tension measurements, the calculated free energy of adsorption E of a silica particle to the oil-water interface passes through a maximum with respect to surfactant concentration, in line with the emulsion stability optimum. This results from a competition between the influence of particle hydrophobicity and interfacial tension on the magnitude of E.  相似文献   

16.
Macroemulsions rendered stable by adsorbed colloidal particles are termed Pickering emulsions. If the volume fraction of dispersed phase exceeds around 0.75, the emulsions are named high internal phase Pickering emulsions abbreviated to HIPPEs, which present new properties and potential applications. We review here the recent progress in preparing and studying HIPPEs of both oil-in-water and water-in-oil types. This includes discussion of the range of solid particle emulsifiers, the choice of the two immiscible liquids and methods for their preparation. As a result of their high interfacial area and long-term stability, HIPPEs are being put to use in many potential applications including drug delivery, catalysis, and in the production of novel porous materials.  相似文献   

17.
Pickering乳液模板法制备Janus粒子   总被引:4,自引:0,他引:4  
本文以SiO2粒子稳定的水包油(O/W)型Pickering乳液作为模板, 在乳液连续相进行SI-ATRP, 将聚合物刷接枝到SiO2粒子外半表面, 破乳得到半修饰的Janus粒子.  相似文献   

18.
The guanidine group-modified silica particles were used as emulsifier to obtain a CO2-responsive Pickering emulsion. To compare the wettability effect of the particles on the stability of the emulsion, both guanidine and alkyl chain were attached on the surface of silica particles. The influences of tension, particles concentration, oil-water fraction, NaCl concentration, and CO2 on Pickering emulsion properties were investigated. Although the particles did not decrease the surface and interfacial tensions of the air/oil-water interfaces, they attached on the oil–water interfaces and stabilized the emulsions at room temperature for at least 4 weeks. Addition of salt increased the emulsion stability and induced phase inversion at high salt concentration. The stabilization–destabilization cycles of the emulsion could be successively controlled by alternative CO2/heating triggers due to the protonation-deprotonation of guanidine groups on the particle surfaces.  相似文献   

19.
Using a range of complementary experiments, a detailed investigation into the behavior of dodecane-water emulsions stabilized by a mixture of silica nanoparticles and pure cationic surfactant has been made. Both emulsifiers prefer to stabilize o/w emulsions. At high pH, particles are ineffective emulsifiers, whereas surfactant-stabilized emulsions become increasingly stable to coalescence with concentration. In mixtures, no emulsion phase inversion occurs although synergism between the emulsifiers leads to enhanced stability at either fixed surfactant concentration or fixed particle concentration. Emulsions are most stable under conditions where particles have negligible charge and are most flocculated. Freeze fracture scanning electron microscopy confirms the presence of particle flocs at drop interfaces. At low pH, particles and surfactant are good emulsifiers alone. Synergism is also displayed in these mixtures, with the extent of creaming being minimum when particles are most flocculated. Experiments have been undertaken in order to offer an explanation for the latter synergy. By determining the adsorption isotherm of surfactant on particles in water, we show that surfactant addition initially leads to particle flocculation followed by re-dispersion. Using suitable contact angle measurements at oil-water-solid interfaces, we show that silica surfaces initially become increasingly hydrophobic upon surfactant addition, as well as surfactant adsorption lowering the oil-water interfacial tension. A competition exists between the influence of surfactant on the contact angle and the tension in the attachment energy of a particle to the interface.  相似文献   

20.
Doubly pH-responsive pickering emulsion   总被引:1,自引:0,他引:1  
A pH-responsive Pickering emulsion has been designed on the basis of commercially available alumina-coated silica nanoparticles (Ludox CL silica particles) and potassium hydrogen phthalate (KHP). KHP was found to bind to cationic particle surfaces at pH values between 3.5 and 5.5, enabling the resulting surface-active particles to stabilize emulsions of xylenes in water. Above and below this pH range, the system demulsifies, resulting in a reversible Pickering emulsifier having two pH-controlled, reversible transitions.  相似文献   

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