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1.
为研究不同种类稳定剂对所制备纳米金溶胶性质的影响。本文以氯金酸为原料,选择柠檬酸三钠、海藻酸钠、壳聚糖3种不同性质的稳定剂分别制备纳米金溶胶,以冷冻前后溶胶颜色变化、溶胶等离子体吸收峰及其峰值的变化及颗粒间的聚集情况为考察指标,研究不同稳定剂所制备的纳米金冷融指示剂冷冻前后的稳定性。结果表明:以柠檬酸三钠为稳定剂所制备的纳米金溶胶颜色经一次冷冻就会由酒红色变为透明无色;以壳聚糖为稳定剂所制备的纳米金溶胶,其颗粒经冷冻后虽会聚集,但颜色不会发生明显变化。以上现象均不符合对指示剂的要求。以2.0%海藻酸钠与10 mL的1.0 mmol/L氯金酸溶液所制备的纳米金溶胶效果最为理想:溶胶经反复冷冻后,颜色由正红色变为紫色,且颜色随冷冻次数的增加而加深,其颗粒间会发生聚集,由单一分散变为聚集成团。以上现象均符合纳米金冷融指示剂的要求,因此以海藻酸钠为稳定剂所制备的纳米金溶胶是一种良好的纳米金冷融指示剂。  相似文献   

2.
首先,采用钛酸四丁酯为先驱物、无水乙醇为溶剂、冰醋酸为抑制剂、十二烷基苯磺酸钠为分散剂,制备纳米二氧化钛溶胶。然后,将单体(丙烯酸、丙烯酸丁酯、甲基丙烯酸甲酯)慢慢滴加到纳米二氧化钛溶胶中,由过硫酸钾引发单体在纳米二氧化钛溶胶粒子表面发生聚合反应,得到纳米二氧化钛被覆聚丙烯酸酯分散液。接着,使用动态光散射仪分析纳米二氧化钛溶胶粒径及其分布,并利用透射电镜观察纳米二氧化钛被覆聚丙烯酸酯分散液形貌,探讨聚合反应的最佳纳米二氧化钛溶胶单体混合液p H值、反应温度,以及纳米二氧化钛溶胶质量分数对纳米二氧化钛被覆聚丙烯酸酯分散液的成膜性能及形成的膜的透光性的影响。结果表明,制备的纳米二氧化钛溶胶的平均粒径为263.0 nm,聚丙烯酸酯包裹纳米二氧化钛溶胶粒子;聚合反应的最佳反应温度为75℃,最佳纳米二氧化钛溶胶单体混合液p H值为8.0,纳米二氧化钛溶胶质量分数最佳为20.0%。  相似文献   

3.
制备乙二醇溶剂中稳定的纳米TiO_2溶胶体系,将其加入聚酯合成中,分析了体系中影响纳米TiO_2分散性因素和纳米TiO_2表面修饰机理,以及纳米TiO_2-乙二醇溶胶在聚酯中的分散性。  相似文献   

4.
采用溶胶-凝胶和表面改性方法制备了两种纳米二氧化钛体系,分别对两体系整理后染色涤纶织物的表面形貌、耐日晒性能和色差进行了研究。实验表明,经两种纳米体系整理后TiO2颗粒在涤纶纤维表面分布状态略不同,但织物能获得同等耐日晒性能。纳米表面改性TiO2体系受焙烘温度的影响较小,且其整理后织物色泽变化很小。实际应用中,纳米表面改性TiO2体系能够替代纳米TiO2溶胶。  相似文献   

5.
考察了影响纳米CaCO3在淀粉液中分散的因素,并对其进行了优化.纳米CaCO3在淀粉液中的分散效果受分散方法、体系黏度、纳米粒子间的距离影响较大,淀粉黏度、淀粉与纳米粒子的比例及固含量几个因素影响体系的黏度及粒子间的距离.纳米CaCO3在淀粉液中最优的分散方法为:先将纳米CaCO3分散液与淀粉液分别进行分散再一起糊化.纳米CaCO3与淀粉的质量比为1∶10、固含量为5%时,分散体系中纳米CaCO3的粒径最小.  相似文献   

6.
马廷方  沈纲 《丝绸》2006,(8):35-37
对纳米氧化钛的分散原理以及工艺因素进行了分析探讨,制备了稳定的纳米氧化钛分散液,并将其应用于涤纶织物进行降解甲醛气体的实验。结果表明,该涤纶织物对甲醛的去除率可达到91.1%。  相似文献   

7.
初生皂法制备硬脂酸钙分散液   总被引:3,自引:0,他引:3  
探讨了初生皂法制备硬脂酸钙分散液的各种工艺条件(乳化温度、转相温度、搅拌和混合乳化剂的用量等)对硬脂酸钙分散液性能的影响.结果表明,CaO在水中转化为Ca(OH)2是影响硬脂酸钙分散液性能的重要原因;A/B/硬脂酸钠混合乳化剂体系是较为理想的硬脂酸钙乳化分散体系;为了得到低粘度、高固含量的产品,应当延长CaO在水中的浸泡时间,使其充分转化为Ca(OH)2并形成石灰乳液.  相似文献   

8.
聚丙烯酸酯/纳米TiO_2复合乳液的制备及应用   总被引:1,自引:0,他引:1  
采用溶胶-凝胶法制备了纳米二氧化钛(TiO2)溶胶,分别考察了溶剂种类和溶剂用量对纳米二氧化钛溶胶的影响。将制得的溶胶与纯聚丙烯酸酯乳液共混,制备聚丙烯酸酯/纳米TiO2复合乳液,并对复合乳液涂膜的力学性能和耐水性能进行检测。最后将复合乳液应用于皮革涂饰,对涂饰后革样的应用性能进行测试。试验结果表明:采用二乙醇胺或三乙醇胺为溶剂制得的TiO2溶胶较为稳定,随着二乙醇胺或三乙醇胺用量的增加,纳米TiO2溶胶的稳定性变好,同时溶胶与乳液的相容性较好。纳米TiO2溶胶的引入使涂饰后革样的耐水性提高17.06%,透水汽性增加23.87%。  相似文献   

9.
测定了常压下25℃时水-醋酸-甲基叔丁基醚-氯化钠体系液液相平衡数据.结果表明,加盐可以改善体系的液液平衡,有利于提高溶剂的选择性.分别采用Othmer-Tobias和Bachman方程对实验数据进行了关联,相关性系数均大于0.991,数据结果可靠.  相似文献   

10.
采用柠檬酸钠还原法制备了银溶胶以及三种不同粒径大小的金溶胶作为拉曼表面增强剂,通过紫外-可见吸收光谱及透射电镜(TEM)比较其尺寸、粒度、分散性及稳定性,后选取盐酸氯丙那林、硫酸特布他林和盐酸班布特罗三种β受体激动剂类药物作为检测对象,观察拉曼信号增强效果。结果表明,金、银溶胶对β受体分子的表面增强拉曼信号增强信号基本上没有干扰。金溶胶的纳米粒子大小对于吸附能力有一定程度的影响,其颗粒大小更易于通过加入柠檬酸钠的方式进行调节,而银纳米溶胶颗粒粒径较不易控制。金溶胶能较长时间保持稳定,而银溶胶较易发生沉淀,但银纳米颗粒与目标分子结合后能产生更为强烈的共振现象,与金溶胶相比具有更强的表面增强活性,在拉曼信号增强目标分子时效果更好。  相似文献   

11.
目的 建立一种适用于测定砧板中五氯酚钠的液液萃取-超高效液相色谱-串联质谱方法。方法 样品采用50%甲醇水溶液(含1%氨水)萃取,超声提取10 min后,用正己烷-二氯甲烷(8∶2,V/V)萃取,氮吹近干,以0.01%氨水和甲醇溶液复溶后进行超高效液相分离,在电喷雾离子源负离子(ESI-)多反应监测(MRM)模式下进行质谱检测。结果 本方法的检出限为0.2 μg/kg,在1、4和20 μg/kg三个加标水平下的回收率为101.4%~108.9%,相对标准偏差为3.5%~7.8%(n=7)。应用该方法检测市售60份砧板,其中1份样品检出五氯酚钠残留,含量为1.16 μg/kg。结论 本方法简便、高效,适用于砧板中痕量五氯酚钠的快速测定,结果准确可靠。  相似文献   

12.
一、前言 醋如同酱油、拌料酱等是以发酵法制成的基础调味料,是加工食品所不可或缺的原料而广被使用。除了做为调味料的用途之外,利用所具有的抗菌性以及健康意识为目的的需求亦屡见不鲜。近年来由于女性的就业人口增加,加上子女数减少、高龄社会  相似文献   

13.
The changes that are being imposed on the liquid milk industry through increased demand for reduced fat milks. increased shop sales and a greater range of container types are considered. These will all lead to increased pressure on doorstep milk prices, which will need to be countered by active marketing.  相似文献   

14.
柴化珍  马学亚 《印染》2013,39(20):35-37
罗伊斯液体还原染料系采用美国RoycevatTM技术生产,具有优良的染色性能和环保性能。通过与传统粉体还原染料进行对比,并将液体还原染料实际应用于纯棉和涤棉织物长车轧染生产中。结果表明,液体还原染料使用简单,力分高,染料提升力好,染色效果与传统粉体染料相当;染深色时染料用量明显减少,生产成本降低;染液COD含量较粉体染料下降50%,降低了染厂污水处理负荷。  相似文献   

15.
A novel, simple and rapid method based on magnetic effervescent tablet-assisted ionic liquid dispersive liquid–liquid microextraction (MEA-IL-DLLME) followed by graphite furnace atomic absorption spectrometry (GFAAS) determination was established for the speciation of selenium in various food and beverage samples. In the procedure, a special magnetic effervescent tablet containing CO2 sources (sodium carbonate and sodium dihydrogenphosphate), ionic liquids and Fe3O4 magnetic nanoparticles (MNPs) was used to combine extractant dispersion and magnetic recovery procedures into a single step. The parameters influencing the microextraction efficiency, such as pH of the sample solution, volume of ionic liquid, amount of MNPs, concentration of the chelating agent, salt effect and matrix effect were investigated and optimised. Under the optimised conditions, the limits of detection (LODs) for Se(IV) were 0.021 μg l1 and the linear dynamic range was 0.05–5.0 μg l1. The relative standard deviation for seven replicate measurements of 1.0 μg l1 of Se(IV) was 2.9%. The accuracy of the developed method was evaluated by analysis of the standard reference materials (GBW10016 tea, GBW10017 milk powder, GBW10043 Liaoning rice, GBW10046 Henan wheat, GBW10048 celery). The proposed method was successfully applied to food and beverage samples including black tea, milk powder, mushroom, soybean, bamboo shoots, energy drink, bottled water, carbonated drink and mineral water for the speciation of Se(IV) and Se(VI) with satisfactory relative recoveries (92.0–108.1%).  相似文献   

16.
高效液相色谱法测定液态奶中的叶酸   总被引:1,自引:0,他引:1  
建立了HPLC二级管阵列检测器检测液态奶中叶酸的方法.该法相关系数为O.9996,平均回收率在81.8%~88.77%之间,最低检测限为1.5μg/L.本方法简单、快捷、灵敏,可用于液态奶中叶酸的日常分析.  相似文献   

17.
2-Iodosobenzoate and N,N-dimethylaniline have been used at pH 6.4 for selective conversion of iodide to 4-iodo-N,N-dimethylaniline which was extracted with ethanol, when the phase separation occurred by addition of ammonium sulphate, a process called salt-assisted liquid–liquid microextraction (SALLME), and analysed by high-performance liquid chromatography-diode array detection. Iodate was reduced to iodide before derivatisation. The method has been optimised for extracting solvent, salt for phase separation, and reaction time. A linear calibration was obtained for 10 μg-10 mg L−1 of iodide with correlation coefficient of 0.9989 and limit of detection of 3.7 μg L−1. The SALLME produced 280-fold enrichment of the derivative. The commercial iodised table salt samples have been found highly inhomogeneous; the RSD in analysis of different aliquots of the same sample ranged 18.0-78.1%. The average recovery of spiked iodide to real samples was 98.4% with an average RSD of 7.9% (range 5.2-12.4%).  相似文献   

18.
A liquid–liquid extraction method was developed for purifying and enriching the sample of 6 azo-dyes (including Para red, Sudan red G, Sudan I, Sudan II, Sudan III and Sudan IV) by formic acid and chloroform. The results indicated that formic acid can facilitate the solution of fat-soluble azo-dyes, which was helpful for the separation of the fat-soluble interferences from the samples. The extracting conditions of 6 azo-dyes were also optimised. And the proposed extraction method was evaluated by the determination of 6 azo-dyes in chilli products. The mean recoveries of 6 azo-dyes were from 94.1% to 99.2% for chilli powder and from 94.2% to 98.6% for chilli spice. The CCα and CCβ obtained for 6 azo-dyes were in the range of 1.7–2.1 and 2.8–3.4 μg/kg for chilli spice and chilli powder. The inexpensive and simple method was acceptable for routine monitoring 6 azo-dyes in chilli products.  相似文献   

19.
A modified dispersive liquid–liquid microextraction (DLLME) technique combined with an HPLC-UV procedure was developed for the extraction and determination of clenbuterol in swine urine. The modification involved the selection of methyl tert-butyl ether (MTBE) as the dispersive solvent, which had a low solubility in aqueous samples, playing the part of dispersion with the help of violent shaking. MTBE improved the partition of clenbuterol into the extractant, and helped the formation of phase separation. Various factors affecting the extraction efficiency including selection of the organic extractant and the dispersive solvent, the volume of extractant and dispersive solvent, salt concentration, NaOH concentration and centrifugation time were evaluated and optimised. Under the optimal conditions, precision, linearity (correlation coefficient, r 2?=?0.996 over the concentration range of 10–1000?ng?ml?1), detection limit (2.4?ng?ml?1) and enrichment factor of 55 were obtained. The modification to the DLLME made it suitable for analytes with pronounced solubility, especially when the compounds are highly polar and thus more difficult to extract effectively by DLLME. The procedure was suitable for the fast screening of clenbuterol residue in swine urine.  相似文献   

20.
This paper describes a simple method based on three-phase hollow-fibre liquid-phase microextraction (HF-LPME) for the determination of phenolic acids in fruit juices. Analytes including gallic acid, p-hydroxy benzoic acid, caffeic acid, syringic acid, p-coumaric acid, ferulic acid, and cinnamic acid were separated and determined using high-performance liquid chromatography–photodiode array detection (HPLC–DAD). Parameters affecting the enrichment factors (EFs) were investigated. These compounds were extracted from 5 mL aqueous samples (pH 2) to a thin layer of organic solvent (hexyl acetate) phase impregnated into the pores of the polypropylene hollow fibre wall, and then back extracted to a basic acceptor solution (0.02 M NaOH). EFs ranged from 15 (gallic acid) to 408 (cinnamic acid). The RSD of the method for the analysis of spiked water and fruit juice samples varied from 3.1% to 11.3%. The LODs ranged from 0.01 (cinnamic acid) to 2.0 (caffeic acid) μg/L.  相似文献   

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