共查询到20条相似文献,搜索用时 125 毫秒
1.
2.
3.
4.
稀土改性二氧化钛电流变液的性能 总被引:9,自引:3,他引:6
用溶胶-凝胶法制备了稀土元素改性的二氧化钛微粉,利用 DSC、TG、XRD等表征微粉,测试了微粉的介电性能,用微粉和甲基硅油配制了无水电流变液.流变学测量结果表明掺杂改性后的二氧化钛电流变液具有比在相同制备条件下所得纯二氧化钛配制电流变液强得多的电流变效应,典型的颗粒/硅油体积比为35%的电流变液,在25℃、直流3kV/mm、剪切速率为1.441s~(-1)条件下的剪切强度可达1.7kPa,电流密度小于10μA/cm~2,零场粘度为3~SPa·s.稀土的掺杂量对电流变效应影响非常明显,存在一个稀土元素的最佳含量范围讨论了电流变液的剪切应力与电场强度、剪切速率的关系。 相似文献
5.
稀土改性二氧化钛的电流变行为与介电性能关系 总被引:4,自引:0,他引:4
采用sol-gel法制备了掺杂稀土改性TiO2颗粒,与甲基硅油配制成电流变液,对电流变液的介电性能进行了测试,结果表明改性后TiO2电流变液的介电常数和介电损耗比纯TiO2电流变液均显著提高,其中介电常数提高2-3倍,△ε′=ε′100Hz-ε′10kHz明显增大,1kHz的介电损耗角正切大于0.1左右电流变液的介电常数与介电损耗达到最大值。稀土掺杂引起TiO2电流变液的介电性能改变是导致改性TiO2电流变液流变学行为变化的起因。另外,电流变液介电性能温度特性的变化可用来解释电流变液的流变学性能随温度变化关系。 相似文献
6.
7.
电流变液夹层圆柱壳声振性能实验研究 总被引:4,自引:3,他引:1
本文选用自行配制的硅油基纳米硅粉和淀粉电流变液 (ERF) ,对灌注电流变液的夹层圆柱壳体的隔声性能及声激励结构响应进行了实验研究 ,对不同电流变液在外加电场下的流变现象进行了定性分析和比较 ,分析了外加电场对电流变液夹层圆柱壳体的声和振动的控制效果。实验结果表明 :施加电场后的电流变液夹层圆柱壳体对处于中、高频率的声波没有明显的吸收和阻隔效果 ,但对于由声激励引起的结构振动有明显的控制作用。无论对声传播还是声激振动 ,电流变材料的影响都是随频率变化而变化的。 相似文献
8.
采用二步复合法制备了一种以高岭土/二甲基亚砜插层化合物为核、羧甲基淀粉为壳的三元纳米复合电流变液材料.XRD测试表明高岭土的层间距由0.715nm扩大到1.120nm.介电性能测试表明三元体系电流变液的介电常数和电导率比原材料电流变液有很大改善,增强了极化能力和介电失配,从而使电流变性能大幅提高.在颗粒/硅油体积比30%和DCE=5kV/mm下,这种材料的静态剪切应力可达17kPa,分别是相同条件下纯高岭土电流变液和高岭土/羧甲基淀粉电流变液的14倍和4.25倍.研究表明,该材料存在一最佳配比,当三元体系质量配比为10.750.6时,纳米协同效应最佳,表现出最强的电流变效应. 相似文献
9.
基于NaY沸石和硅油的电流变液的动态响应实验研究 总被引:1,自引:0,他引:1
构建了对电流变液对电场的动态响应过程进行研究的测试系统。此系统的响应快于其它用于同样研究的系统,可以达到0.01ms的响应速度。使用这个测试系统对电流变液的极化和退极化过程以及在不同剪切速率下对电场的动态响应进行了研究表明,基于NaY沸石和硅油的电流变液对电场的上升响应时间常数在毫秒量级,且与剪切速率的-3/4次方成正比,与其它研究人员的理论描述基本一致。直流电场关闭时,在1ms左右电流变液就回复到了原有零电场状态。剪切速率越高,电流变液回复所需时间也越短。另外发现剪切应力有0.3ms左右时间延迟。 相似文献
10.
11.
聚邻苯二胺/蒙脱土纳米复合材料的合成及其电流变效应 总被引:2,自引:2,他引:0
用乳液共混插层法制备了聚邻苯二胺/蒙脱土纳米复合材料微粒,通过IR、XRD及TEM对其结构进行了表征。 结果发现,邻苯二胺插入蒙脱土层间聚合后,导致蒙脱土片层之间的剥离,形成纳米复合材料。 将其分散在甲基硅油中(体积分数,22%)配制成无水电流变液,该复合材料表现出较大的协同效应,具有较好的电流变行为。实验结果表明在外加电场下,其电流变效应比聚邻苯二胺、蒙脱土均有显著提高。 在3 kV/mm(DC, 74.5 s-1)时,剪切强度达8.27 kPa;同时抗沉降性极好,静置60 d沉淀率小于3%。介电性能测试表明,聚邻苯二胺/蒙脱土纳米颗粒的介电常数和介电损耗较蒙脱土和聚邻苯二胺均有一定提高,电导率也达到了最佳范围。 相似文献
12.
Ying Dan Liu Ha Young Kim Ji Eun Kim In Gu Kim Hyoung Jin Choi Soo-Jin Park 《Materials Chemistry and Physics》2014
As a potential candidate for electrorheological (ER) materials, polyaniline (PANI) nanofibers were synthesized via an interfacial polymerization route, because of their easy synthesis, high stability, controllable conductivity and good ER response. In this study, a new dopant, indole-2-carboxylic acid, was used to improve the ER performance. The synthesized PANI nanofibers were dispersed in silicone oil at 10 vol% and their rheological properties as an ER fluid were examined using a rotational rheometer under a variety of electric field strengths. In addition, their dielectric properties were studied using a LCR meter. The results showed that indole-2-carboxylic acid, which has high polarizability, enhanced the ER effect of PANI nanofibers, showing that polarizability is an important parameter affecting the ER behavior. 相似文献
13.
14.
Herein, the effect of the degree of deacetylation (DD) on the gelation of the chitosan dispersed suspension as an electrorheological (ER) fluid under an electric field is presented. The fluids were prepared by dispersing the chitin and the chitosan particles having various DDs into silicone oil, and they were evaluated under various electric fields. The alignment of chitosan particles in the fluid was also observed using an optical microscope under the electric field. The formed fibrous structure between electrodes are though to continue to the viscosity increase, because an attempt to move one electrode relative to the order would be hindered by the drag of the dangling fibrils. A noteworthy result is that the region of the frequency for gel state of the ER fluids increased in the order of chitosan DD 99.3, 93.4, 73.2, 83.8, and 87.3% under electric fields while the modulus of the fluids increased in the reverse order. This order was well-matched with the result of dielectric constants and yield stresses of ER fluids. The study of influence of DD on the gelation of the chitosan dispersed suspension under an electric field shows the relevance of the chemical composition of the heteropolysaccharide (chitin-chitosan copolymer) to the rheological and electric properties of ER suspensions. 相似文献
15.
Piyanoot Hiamtup Anuvat Sirivat Alexander M. Jamieson 《Journal of Materials Science》2010,45(7):1972-1976
An electrorheological (ER) fluid, consisting of polydisperse dedoped polyaniline (PANI) particles, having irregular shapes,
dispersed in silicone oil, was subjected to cyclic strain annealing treatments using oscillatory shear, under an external
electric field. After each annealing period, the sample was subjected to a controlled-strain sweep, to determine the yield
stress, and to erase the ER structure. During each annealing cycle, the storage modulus and the yield stress were observed
to increase, and the loss modulus to decrease, each eventually approaching an asymptotic constant value. These observations
in oscillatory shear complement our previous observations of a strain-hardening effect in a PANI/silicone oil ER fluid subjected
to unidirectional creep tests. 相似文献
16.
以间苯二胺,2,5-二氧环己二甲酸二甲酯为原料,经缩合、闭环、氧化等反应,制得了聚喹吖(2,3b)啶-12,14(5,7)二酮(PQA)并进行了表征;并以PQA为基础粒子制备了无水型电流变流体(ERF),研究了其电流变性能。考察了溴代二苯甲烷(BDPM)-PQA体系中粒子浓度、电场强度、剪切速率等对电流变流体性能的影响,并从聚合物粒子的分子结构特点出发,对该体系的电流变效应进行了解释;对比了不同分散介质(BDPM及硅油)对电流变效应的影响。结果表明,PQA在BDPM中具有较佳的电流变效应,当粒子的质量分数为30%,外加电场为3 kV/mm时,屈服应力达4.0 kPa。 相似文献
17.
以草酸氧钛纳米颗粒为分散相,以不同黏度的二甲基硅油(运动学黏度为10 cSt、50 cSt、100 cSt、500 cSt和1000 cSt)为基液制备电流变液,测试其剪切屈服强度、零场黏度、电流变效率、响应时间及沉降稳定性,研究了基液黏度对草酸氧钛电流变液性能的影响。结果表明,以50 cSt二甲基硅油为基液的电流变液具有最佳的电流变效率,以100 cSt二甲基硅油为基液的电流变液具有最短的响应时间和较高的沉降稳定性。其机制是,较高的基液黏度可提供较大的黏滞阻力,但易引起颗粒的团聚。 相似文献
18.
对甲苯磺酸掺杂聚邻甲苯胺的合成及电流变性能 总被引:1,自引:0,他引:1
以对甲苯磺酸(TSA)作为掺杂剂和乳化剂,乳液聚合合成了对甲苯磺酸掺杂聚邻甲苯胺(TSA-POT)。采用红外光谱、热重分析和扫描电镜对聚合物的结构、热稳定性及形貌进行了表征。制备了TSA-POT/硅油(SO)无水型电流变流体(ER流体),测试了其电流变性能,考察了电场强度、反掺杂条件、粒子浓度等因素对TSA-POT/SO体系电流变性能的影响。结果表明,由于强极性的磺酸基团与聚邻甲苯胺的主链相连,极大地改善了聚合物粒子的极化性能,因此TSA-POT/SO体系的电流变性能显著改善。结果同时表明,低浓度的TSA-POT/SO体系的屈服应力与电场强度具有二次线性关系。 相似文献
19.
高岭土/羧甲基淀粉插层复合微粒及其电流变性能 总被引:1,自引:0,他引:1
以二甲基亚砜为前驱体,通过二次插层取代,夹带入羧甲基淀粉,制备出高岭土/羧甲基淀粉剥离型插层复合微粒.羧甲基淀粉插层引起高岭土片层之间的剥离,高岭土片层在羧甲基淀粉中均匀分散.二次插层取代使插层复合物电流变液的介电常数和电导率显著改善.高岭土/羧甲基淀粉复合材料具有较好的协同效应,其电流变液的静态剪切应力值分别是纯高岭土的3.60倍和羧甲基淀粉的2.24倍.复合材料的电流变性能与复合物中羧甲基淀粉的含量有密切关系.复合材料电流变液的工作温区大幅扩展(20~90℃),抗沉降性明显提高。 相似文献
20.
Ying Dan Liu Xue-Mei Quan Bo Mi Lee In Gu Kim Hyoung Jin Choi 《Journal of Materials Science》2014,49(6):2618-2623
Silica/ammonium persulfate (APS) microspheres were fabricated by coating APS on the surface of ~2 μm sized silica particles and applied as a candidate for electrorheological (ER) materials. The morphologies of these particles were observed by SEM. Chemical compositions and structure of the particles were confirmed by EDS and FT-IR. Thermogravimetric analysis was used to examine the amount of APS coating on the silica particles. A 10 vol% ER fluid based on the fabricated particles was prepared by dispersing them into hydroxyl group-terminated silicone oil. Typical ER properties were obtained using a rotational rheometer under an applied electric field at a controlled shear rate test. These properties were also correlated with its dielectric spectra. 相似文献