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采用硅烷偶联剂A-172改性空心SiO2纳米球,使其表面带有富含碳碳双键的活性基团,有效地增强了空心SiO2纳米球的疏水性,明显减少了团聚现象.进一步将其引入到纯丙乳液中,研究了其对纯丙乳液性能的影响.使用扫描电镜(SEM)、高倍透射电镜(HRTEM)观察了改性前后空心SiO2纳米球的形貌;使用傅里叶红外(FT-IR)、热重分析(TG)、附着力测试等对改性纯丙乳液的结构及性能进行了表征.结果表明:硅烷偶联剂改性后的空心SiO2纳米球在有机溶剂中的分散性明显增强,且并未破坏其形貌结构;空心SiO2纳米球改性后的纯丙乳液热稳定性及附着力明显提高. 相似文献
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采用辛胺改性海藻酸钠,并以其通过物理混合和化学接枝2种途径活化SiO2纳米粒,利用红外光谱、核磁共振氢谱和动态光散射等对产物进行了表征,并超声乳化制备了其相应的Pickering乳液,进而对乳液的形貌进行了观察。结果表明:海藻酸钠上成功接枝了辛胺侧链;经2种途径活化后的SiO2纳米粒粒径均大于未活化的SiO2纳米粒,分别增至467.0和414.4 nm;其Zeta电位较SiO2纳米粒自身的-17.0 mV也发生了变化,分别为-43.9和-35.2 mV。同时,活化后的纳米粒具有了较好的乳化性能,尤其是通过表面化学接枝改性海藻酸钠的SiO2纳米粒,其形成的Pickering乳液液滴分散性好,大小均一,平均粒径为5μm。 相似文献
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采用半连续乳液聚合工艺,合成了纳米二氧化硅(SiO2)改性聚醋酸乙烯酯(PVAc)有机/无机杂化乳液。研究了纳米SiO2添加量对聚醋酸乙烯酯乳液聚合稳定性、贮存稳定性、黏度、粘接强度的影响。结果表明,经超声处理的SiO2粒子加入乳液中乳胶粒分散状态良好,合成的SiO2/PVAc复合乳液放置6个月未产生凝聚、分层等不稳定现象;乳液黏度随SiO2含量增加由532.0mPa·s降低为343.0mPa·s。扫描电镜(SEM)观察,纳米SiO2改性PVAc乳液分散均匀,乳胶颗粒聚集现象减少,压缩剪切强度随纳米SiO2含量的增加呈先增大后减小的趋势,用量为6‰时可达10.28MPa。 相似文献
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本文以γ-氨基丙基三甲氧基硅烷(APTMS)为改性剂,对纳米二氧化硅进行表面改性,并将其整理到棉织物上,随后利用十六烷基三甲氧基硅烷(HDTMS)对织物进行修饰,通过两步法获得棉织物超疏水界面.探讨反应条件对改性纳米SiO2的影响,并对改性纳米SiO2和整理后棉织物进行测试表征.结果表明,当温度为30℃,正硅酸四乙酯(rEOS)浓度为3%和APTMS浓度为2%,氨水用量为2 mL时,制备的改性纳米SiO2溶胶平均粒径为65.88nm,PDI为0.096,分散性较好.两步法整理后的棉织物接触角为150.36°,滚动角为8°,实现了超疏水效果,并且洗涤20次后仍具有一定疏水性. 相似文献
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乙烯酮(双乙烯酮)是十分重要的化工中间体,其下游产品较多。江苏某化工厂开发生产乙烯酮(双乙烯酮)下游产品三十多个,年生产规模三万多吨,是国内以乙烯酮(双乙烯酮)为中间体生产精细化学品的综合骨干企业。针对乙烯酮(双乙烯酮)下游产品废水特点,该厂结合企业实际,开展了产品优化,结构调整,清洁生产,资源循环利用,节水降耗等工作,从源头削减了污染物的生产。同时投资二千多万元新建预处理装置三套,6000m3/d废水生化处理装置一套,使全厂乙烯酮(双乙烯酮)下游产品的废水得到了有效的治理。 相似文献
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The objective of the study was to explore the effect of the degree of deacetylation (DD) of the chitosan used on the degradation rate and rate constant during ultrasonic degradation. Chitin was extracted from red shrimp process waste. Four different DD chitosans were prepared from chitin by alkali deacetylation. Those chitosans were degraded by ultrasonic radiation to different molecular weights. Changes of the molecular weight were determined by light scattering, and data of molecular weight changes were used to calculate the degradation rate and rate constant. The results were as follows: The molecular weight of chitosans decreased with an increasing ultrasonication time. The curves of the molecular weight versus the ultrasonication time were broken at 1‐h treatment. The degradation rate and rate constant of sonolysis decreased with an increasing ultrasonication time. This may be because the chances of being attacked by the cavitation energy increased with an increasing molecular weight species and may be because smaller molecular weight species have shorter relaxation times and, thus, can alleviate the sonication stress easier. However, the degradation rate and rate constant of sonolysis increased with an increasing DD of the chitosan used. This may be because the flexibilitier molecules of higher DD chitosans are more susceptible to the shear force of elongation flow generated by the cavitation field or due to the bond energy difference of acetamido and β‐1,4‐glucoside linkage or hydrogen bonds. Breakage of the β‐1,4‐glucoside linkage will result in lower molecular weight and an increasing reaction rate and rate constant. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3526–3531, 2003 相似文献
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我厂3号回转窑(Φ4m×60m)生产线在1996年年底由SP窑(产量912t/d)改为NSP窑(产量1320t/d),预分解系统为四级旋风预热器带离线式分解炉 相似文献
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Conclusions It is significant that the purification on a single passage of viscose through porous ceramic corresponds to the result of a two-stage filtration of it in industrial filter-presses with standard fillings.Kiev Combine. Kiev Technological Institute of Light Industry. Translated from Khimicheskie Volokna, No. 3, pp. 20–22, May–June, 1969. 相似文献
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A refined nonlinear value of the main parameter of a material, i.e., the elongation modulus versus the instant temperature value, was suggested for introduction into the computational algorithm of tempering stresses. 相似文献