首页 | 官方网站   微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 140 毫秒
1.
以氟硅酸废水和氢氧化铝为原料通过化学沉淀法制得沉淀白炭黑;以月桂酸钠为改性剂对所制得的白炭黑进行了表面改性,考察了月桂酸钠添加量和改性时间对白炭黑疏水性和分散性的影响。采用场发射扫描电子显微镜(FE-SEM)、傅里叶变换红外光谱仪(FT-IR)、激光粒度分析仪、X射线衍射分析仪(XRD)等对改性前后的白炭黑样品的表面形貌、结构性能及分散性等进行了表征和分析。结果表明:当改性剂月桂酸钠添加量为2%,改性时间为40min时,可制得接触角为132.5°的疏水性白炭黑。改性后白炭黑样品的平均粒径(D50)从32.4μm减小至790nm,比表面积(BET值)从75m~2/g增加到165m~2/g,吸油值(DBP值)从2.25mL/g增加到3.12mL/g。改性后白炭黑样品的分散性和稳定性明显增加,团聚现象减少。  相似文献   

2.
用液相包覆法研究了非离子表面活性剂Span80在锐钛矿型微米和纳米TiO2颗粒上的包覆工艺,并在研制的电流变仪上测定了不同电流变液配方TiO2/硅油电流变体的静态剪切应力τ与外加直流电场强度E的关系.结果表明:颗粒完全被Span80包覆,表面活性剂提高TiO2分散性和悬浮性;在直流电场作用下,表面活性剂Span80在颗粒表面形成的胶层促进电流变体的极化;加入适量促进剂提高了电流变性;在微米TiO2/硅油体系中混入少量纳米TiO2可提高电流变体的抗剪应力.  相似文献   

3.
针对纳米二氧化钛(TiO2)颗粒粒径小、表面活性大、易团聚的问题,采用硅烷偶联剂KH-560对TiO2进行表面改性,并与聚丙烯树脂(PP)在双螺杆挤出机上熔融共混得到改性PP;通过FT-IR、TG、SEM等测试手段对改性纳米TiO2颗粒进行了表征,讨论了纳米TiO2的改性程度及其在PP中的分散性。结果表明:硅烷偶联剂已经成功的包覆在纳米TiO2的表面;同时在碱性环境下纳米TiO2表面包覆的有机物含量最多;当在碱性环境下表面改性的纳米TiO2为PP质量的3%时,在聚丙烯树脂中分散较均匀。  相似文献   

4.
通过氢氧化铝Al(OH)3和十二烷基硫酸钠(SDS)对纳米TiO2的表面进行包覆和改性处理,以提高纳米TiO2水性浆料的分散性。经SDS对表面包覆Al(OH)3的纳米TiO2进行改性后,制成的浆料平均粒径为82nm、储存稳定性达50d以上。将纳米TiO2浆料加入到防腐涂料中,涂料的各种性能均有提高,且在纳米TiO2的添加量为2‰时,涂膜的综合性能最好。  相似文献   

5.
采用硅烷偶联剂KH550对纳米TiO2进行表面改性,将改性纳米TiO2与三聚氰胺甲醛树脂(MF)混合,制备MF/纳米TiO2复合树脂。红外分析表明偶联剂成功接枝于纳米TiO2表面;热失重分析得出表面改性的最佳工艺为:改性剂的添加量2%,改性温度70℃,改性时间120min;透射电镜分析表明纳米TiO2的表面改性提高了其在有机溶剂中的分散性;研究TiO2添加量对MF/纳米TiO2复合树脂的粘度、固化时间、固化温度和抗菌性的影响,结果表明TiO2的添加对树脂固化时间和固化温度影响很小,但能显著提高材料的粘度和抗菌性能。  相似文献   

6.
航空复合材料结构用纳米TiO2改性涂料的制备及性能   总被引:1,自引:0,他引:1  
李梦  樊占鹏  杨文锋  秦文峰 《功能材料》2013,44(8):1200-1203
利用KH-550硅烷对金红石型纳米TiO2的表面进行了包覆处理,研究了使用不同分散剂的条件下,未包覆和经包覆的纳米TiO2粉体在ECL-GC-7航空清漆中的分散性。将经过包覆的纳米TiO2加入到ECL-GC航空涂料中进行改性,表征了改性涂层的紫外光吸收和抗老化性能。研究发现,通过包覆处理并配合使用R912分散剂,航空清漆中纳米粉体出现可目视观察的初始沉淀时间在4h以上,粉体的稳定分散状态可以保持到200h以上。经纳米TiO2改性后,涂层的紫外光吸收能力和抗老化性能均有所提高。在纳米TiO2添加量为2.0%(质量分数)时,改性涂料的性价比较佳。  相似文献   

7.
表面活性剂对二氧化钛纳米流体分散性的影响   总被引:1,自引:1,他引:0  
莫松平  陈颖  李兴  罗向龙 《材料导报》2013,27(12):43-46
通过二步法将纳米二氧化钛分散到去离子水中,制备TiO2-水纳米流体。通过加入3种不同的表面活性剂作为分散剂,即阴离子表面活性剂十二烷基苯磺酸钠(SDBS)、非离子表面活性剂聚乙烯吡咯烷酮(PVP)和阳离子表面活性剂十六烷基三甲基溴化铵(CTAB)制备出3种不同的纳米流体。用纳米粒度分析仪测定纳米流体中的纳米粒子的粒径和粒径分布,用Zeta电位分析仪测量纳米流体的电位,分析了不同浓度、不同种类的表面活性剂对水基TiO2纳米流体分散性的影响。  相似文献   

8.
纳米TiO_2/SiO_2的制备与表征及其光催化活性的研究   总被引:2,自引:0,他引:2  
针对二氧化钛(TiO2)纳米颗粒极易团聚、分散性差的问题,以提高TiO2分散稳定性与光催化活性为目的,采用并流中和法,以锐钛矿型纳米TiO2粉体为载体,硅酸钠(Na2SiO3)为包覆剂,使用硫酸(H2SO4)调节pH值,在纳米TiO2表面包覆致密的氧化硅(SiO2)膜。借助Fourier变换红外光谱(FTIR),X射线能量散射谱(EDS)和场发射扫描电子显微镜(FESEM)表征样品的键合情况、表面化学成分、分散性,同时借助紫外-可见分光光度计(UV-Vis Spectrophotometer)以亚甲基蓝的光催化降解反应对其光催化活性进行评价。FTIR和EDS结果表明:采用该包覆法后,SiO2以化学键合的方式沉积在纳米TiO2表面,在包覆层和纳米TiO2颗粒之间的界面上形成了Ti—O—Si键。SEM结果表明:TiO2/SiO2纳米复合粒子分散均匀,无严重团聚和大块堆积现象。光催化实验结果表明:以SiO2表面包覆后的TiO2颗粒光催化活性明显高于纯TiO2。  相似文献   

9.
亲油性纳米TiO2/PMMA复合粒子的制备及表征   总被引:1,自引:0,他引:1  
采用种子乳液聚合法对纳米TiO2进行表面改性,将甲基丙烯酸甲酯包覆在纳米TiO2表面,形成TiO2/PMMA复合粒子。采用FT-IR、UV-Vis、XPS、TEM等分析手段对所得产物的表观形貌、所携带官能团、表面元素变化和在有机溶剂中的分散性等进行了表征。结果表明,复合粒子呈现核壳结构,粒子的团聚现象和分散性都得到改善,亲油性增强。  相似文献   

10.
利用硅烷偶联剂γ-MPS(KH570)对纳米TiO2进行表面预处理,在此基础上通过原位聚合的方法,制备出聚甲基丙烯酸甲酯(PMMA)接枝包覆的纳米TiO2.运用FT-IR、XPS、TEM等测试手段对改性前后纳米TiO2进行了表征,通过紫外人工加速老化实验比较了其对白色油墨抗老化性能的影响,结果表明:KH570与纳米TiO2表面羟基发生了缩合反应,PMMA在粒子表面实现了接枝聚合,PMMA接枝包覆后的纳米TiO2亲油性增强,分散性提高,团聚减少;在改性油墨的应用中,添加质量分数为2%的纳米TiO2-g-PMMA的油墨在经过336h老化后,色差值仅为0.855,相比未改性油墨抗老化性能提高了18.6%.  相似文献   

11.
在微米α-Al2O3粉体悬浮液中分别加入无机电解质类分散剂六偏磷酸钠、阳离子型表面活性剂十六烷基三甲基氯化铵、阴离子型表面活性剂油酸和非离子型表面活性剂异丙醇胺,并对悬浮液进行球磨分散,研究分散剂加球磨复合分散下的最优分散剂及最佳球磨参数;引入超声分散,对比分析在加入分散剂的情况下,先球磨再超声和只进行球磨时的分散效果。结果表明,采用十六烷基三甲基氯化铵为分散剂,先球磨2 h再超声分散15 min的分散效果最好,沉降24 h后的悬浮率为62%左右,平均粒径为243 nm。  相似文献   

12.
纳米TiO2光催化材料分散性及其降解效率研究   总被引:1,自引:0,他引:1  
采用苯丙乳液、锐钛型纳米级二氧化钛和表面活性剂,制得应用于道路交通设施中的光催化净化大气环保材料,在日光照射下降解汽车尾气中的有害气体.研究了分散方法、分散剂的种类、分散剂的浓度及分散时间对纳米TiO2分散性的影响,利用透射电镜对其分散情况进行观察,并对其分散机理进行探讨与研究.结果表明,采用合理的分散方法和适量的表面活性剂能有效改善纳米TiO2在水中的分散度,提高颗粒的稳定性,增强了光催化材料的光降解能力,有效提高了对汽车尾气中有害气体的降解能力.  相似文献   

13.
Mesoporous titania was obtained by gelation of tetraisopropyl orthotitanate in aqueous or alcoholic solutions with addition of a cationic or anionic surfactant. The gels were dried and calcined to obtain the oxides. The dried samples and the oxides were characterized by thermal analysis, N2- adsorption measurements, infrared spectroscopy, X-ray diffraction and titration with n-butylamine. The effect of the type of surfactant, the chain length of the surfactant and the synthesis method on the textural and surface characteristics of the oxides obtained has been investigated. Cationic surfactants such as dodecyltrimethylammoniumbromide and cetyltrimethylammoniumbromide are effective in controlling the pore size and in increasing the pore volume and the surface area. On the contrary, the sodium dodecylsulphate employed as an anionic surfactant is not incorporated to the hydrous titanium oxide network. The use of a surfactant in the preparation enhances the acid strength of the surface sites of the titanium oxide formed.  相似文献   

14.
用阴离子表面活性剂硬脂酸钠、十二烷基苯磺酸钠和十二烷基磺酸钠分别与非离子表面活性剂曲拉通100组合,制备阴-非离子型有机蒙脱石粉体。通过X射线粉晶衍射分析,研究阴-非离子型有机蒙脱石粉体的制备、阴离子表面活性剂种类和蒙脱石类型对蒙脱石改性效果的影响。结果表明,3种阴离子表面活性剂均能进入蒙脱石层间,得到层间距分别为5.65、4.29、3.73 nm的阴-非离子型有机蒙脱石。用阴-非离子表面活性剂改性不同类型蒙脱石的研究结果表明,蒙脱石的膨胀容明显影响阴-非离子型改性剂改性蒙脱石的效果,并呈规律性变化,蒙脱石的膨胀容值越大,改性效果越好。  相似文献   

15.
The effect of incorporation of an anionic [sodium dodecyl sulfate (SDS) or dioctylsulfosuccinate (DSS)] or nonionic [Tween 60 (TW60)] surfactant on the properties of ketoprofen solid dispersions in polyethylene glycol 15000 (PEG) has been investigated. Physicochemical and morphological properties of the various solid systems were determined by differential scanning calorimetry, hot stage microscopy, X-ray powder diffraction analysis, and scanning electron microscopy. The results from dissolution studies, performed according to the USP 24 basket method, indicated that all ternary dispersed systems were significantly (p < 0.001) more efficacious than the corresponding binary ones, by virtue of the additive wetting and solubilizing effect due to the presence of the surfactant. The relative effectiveness of the incorporated surfactant was in the same order as found in phase-solubility studies (i.e., SDS > DSS > TW60). With regard to the solid dispersion preparation method, coevaporated products always gave better results than the corresponding cofused ones; however, this effect was statistically significant (p < 0.001) only in the initial phase of the dissolution process. The most effective solid dispersion was the 10-80-10 w/w drug-PEG-SDS ternary coevaporate, which allowed dissolution of 50% drug after only 6 min (in comparison with > 120 min for drug alone and 17 min for the binary coevaporate) and dissolution of about 100% drug after 30 min (in comparison with > 120 min for the binary coevaporate).  相似文献   

16.
无机粉体的聚合物胶囊化过程研究   总被引:33,自引:0,他引:33  
采用阴离子表面活性剂十二烷基硫酸钠(SDS)处理二氧化钛粒子,然后以及这样粒子为核心,用原位聚合方法制得了二氧化钛-聚合物复合胶囊化粒子,探讨了复合粒子形成的条件并推测其形成机理,研究了聚合条件对胶囊化过程的影响。  相似文献   

17.
The effect of incorporation of an anionic [sodium dodecyl sulfate (SDS) or dioctylsulfosuccinate (DSS)] or nonionic [Tween 60 (TW60)] surfactant on the properties of ketoprofen solid dispersions in polyethylene glycol 15000 (PEG) has been investigated. Physicochemical and morphological properties of the various solid systems were determined by differential scanning calorimetry, hot stage microscopy, X-ray powder diffraction analysis, and scanning electron microscopy. The results from dissolution studies, performed according to the USP 24 basket method, indicated that all ternary dispersed systems were significantly (p < 0.001) more efficacious than the corresponding binary ones, by virtue of the additive wetting and solubilizing effect due to the presence of the surfactant. The relative effectiveness of the incorporated surfactant was in the same order as found in phase-solubility studies (i.e., SDS > DSS > TW60). With regard to the solid dispersion preparation method, coevaporated products always gave better results than the corresponding cofused ones; however, this effect was statistically significant (p < 0.001) only in the initial phase of the dissolution process. The most effective solid dispersion was the 10-80-10 w/w drug-PEG-SDS ternary coevaporate, which allowed dissolution of 50% drug after only 6 min (in comparison with > 120 min for drug alone and 17 min for the binary coevaporate) and dissolution of about 100% drug after 30 min (in comparison with > 120 min for the binary coevaporate).  相似文献   

18.
为了使纳米锡粉在乙二醇水溶液中良好稳定地分散,通过直流电弧等离子体蒸发法制备平均粒径为106 nm的纳米锡粉,以十二烷基硫酸钠、六偏磷酸钠、聚乙二醇为分散剂研究纳米锡粉在乙二醇水溶液中的分散性能,分析分散时间、分散剂类型及含量对锡粉分散性能的影响。结果表明,不同分散剂的加入对锡粉颗粒在乙二醇水溶液中的分散稳定性都有所提高,随着超声时间的延长和分散剂浓度的增大,粉体的分散效果先增强后减弱;纳米锡粉在乙二醇水溶液中的最佳分散工艺是加入质量分数为3%的十二烷基硫酸钠,超声时间为60 min。  相似文献   

19.
钛白粉在实际应用中由于其光化学活性和在有机颜料中的絮凝等问题严重的影响它的应用,对钛白粉表面进行无机、有机包膜处理可以大大改善它的性能。本文主要介绍了包膜机理、包膜的工艺过程及包膜中应控制的因素,总结了存在问题及今后的发展趋势。  相似文献   

20.
A new micellar electrokinetic chromatography (MEKC) procedure has been developed that allows the use of the anionic surfactant sodium dodecyl sulfate (SDS) together with separation buffers at pHs as low as 1. The technique is based on the employment of a high molecular weight polyethylenimine (PEI)-coated capillary that provides strong cathodal electroosmotic flows at acidic pHs when SDS is added to the running buffer. The procedure is easy to implement since the capillary coating is done by just flushing a PEI aqueous solution through the capillary and the subsequent steps are the same as those for any MEKC protocol. Moreover, the coating renewal provides reproducible separations between injections (migration time RSD values lower than 1.82 and 3.44% were obtained for the same day and three different days, respectively). The good possibilities of this system are demonstrated by showing the separation of a group of eight polyphenolic compounds within a separation time shorter than 2 min. This procedure allows one to extend the optimization of SDS-MEKC separations to the very acidic pH range too.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司    京ICP备09084417号-23

京公网安备 11010802026262号