0-3型水泥基压电复合材料的制备与改性

发布时间：2018-01-09 06:39

  本文关键词：0-3型水泥基压电复合材料的制备与改性　出处：《西安科技大学》2017年硕士论文　论文类型：学位论文

  更多相关文章： 水泥基压电复合材料 压电性能 介电性能 CNTs PVA

【摘要】：水泥基压电复合材料(CPC)兼具感知与驱动功能,制备工艺简单、生产成本低,与混凝土有着相似的物理化学性质,能克服传统压电材料与混凝土兼容性差、阻抗匹配度低的难题,使用该类压电复合材料作为传感器对混凝土结构进行健康监测有望实现更高的精度,对该类材料的研究对土木工程实现智能化发展具有重要的意义。本文主要研究组分、成型工艺、极化工艺对CPC性能的影响,并探究了改性剂碳纳米管(CNTs)和聚乙烯醇(PVA)对CPC性能的影响。通过X射线衍射仪(XRD)、红外光谱(FTIR)、扫描电镜(SEM)、透射电镜(TEM)等手段对CPC进行表征。研究组分对CPC性能的影响,结果表明:以硫铝酸盐水泥为基体的CPC的压电压应变常数(d33)、压电电压常数(g33)和机电耦合系数(Kt)均要优于以白水泥和普通硅酸盐水泥为基体的CPC的值。CPC在水化初期,压电性能不断增加,10d后CPC的压电性能趋于稳定,水泥基体紧密包裹功能相颗粒。SEM分析表明功能相颗粒粒径越大彼此间接触率越高,大粒径功能相颗粒的CPC具有更高的d33、g33和介电常数(εr),大粒径功能相水泥基压电复合材料联结方式更近于并联模型,但功能相颗粒粒径超过126μm时,压电性能趋于平缓,且不利于机电耦合性能和机械品质因数的提高;随着功能相体积含量的增加,CPC的d33、g33和εr均不断增大,SEM分析表明功能相含量越高,相互间的接触率就越高,但功能相体积含量超过60%时,机电耦合性能和机械品质因数均有所降低。研究成型压力和极化工艺对CPC性能的影响。结果表明:成型压力越大,CPC的d33和εr均越大,但SEM分析表明过高的压力会导致基体与功能相间产生层裂,从而使得材料的综合性能下降。本文中最佳的成型压力为90MPa。本文中最佳的极化工艺参数为:极化温度为40A℃;极化电压为4kV/mm;极化时间为15min。研究不同改性物对CPC性能的影响。结果表明:不同方法处理的CNTs的分散性不相同,TEM分析表明使用乳化剂OP-10处理的CNTs尺寸较大,分布也较均匀,综合性能最优。FTIR分析表明CNTs的掺入会与水泥之间产生键和,但不影响水泥的水化。随着CNTs掺量的增加,CPC的d33、εr和Kt均增大,当CNTs体积掺量达到0.7%时,d33达到最大值42.3pC/N。CNTs的加入可以使得CPC的极化温度降至为室温。PVA掺入可以与水泥基体间产生键合,在0-3%PVA体积掺量范围内,水泥基压电复合材料的d33、g33和Kt值均不断提高,气孔率分析表明PVA掺入可以降低CPC的气孔率而增大其致密度。在大于3%体积掺量时,CPC综合性能下降,SEM和红外分析表明过多的PVA会在水泥和功能相颗粒表面形成一层片状有机膜,这阻碍了水泥基体的水化,且对后期的极化不利。对水泥基压电复合材料改性优化可以提高该类材料对混凝土内部结构健康监测的准确率,增加其应用可行性。这对减少大型土木工程事故率、降低人员伤亡率以及国家和社会财产损失具有重大意义。
[Abstract]:Cement-based piezoelectric composite (CPC) has both sensing and driving functions, simple preparation process, low production cost and similar physical and chemical properties to concrete. It can overcome the problems of poor compatibility between traditional piezoelectric materials and concrete and low impedance matching. Using this kind of piezoelectric composite materials as sensors for health monitoring of concrete structures is expected to achieve higher accuracy. The research on this kind of materials is of great significance to the intelligent development of civil engineering. This paper mainly studies the effect of molding technology and polarization process on the properties of CPC. The effects of modifiers such as carbon nanotubes (CNTs) and polyvinyl alcohol (PVA) on the properties of CPC were investigated. CPC was characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The effect of the study group on the properties of CPC was studied. The results show that the voltage strain constant of CPC based on sulphoaluminate cement is d33). The piezoelectric voltage constant g33) and the electromechanical coupling coefficient (Kt) are better than the values of CPC based on white cement and ordinary Portland cement. After 10 days, the piezoelectric properties of CPC tended to be stable, and the results showed that the larger the particle size of the functional phase was, the higher the contact rate between the particles was. The CPC with large particle size functional phase particle has higher D33 / G33 and dielectric constant (蔚 ~ (r)), and the connection mode of large particle size functional phase cement-based piezoelectric composite is more similar to that of parallel model. However, when the particle size of functional phase is more than 126 渭 m, the piezoelectric performance tends to be gentle, which is not conducive to the improvement of mechanical and electrical coupling performance and mechanical quality factor. SEM analysis shows that the higher the content of functional phase, the higher the contact rate of CPC. However, when the volume content of functional phase exceeds 60, the mechanical and electrical coupling performance and mechanical quality factor decrease. The influence of molding pressure and polarization process on the properties of CPC is studied. The results show that the higher the molding pressure is, the higher the forming pressure is. The larger the d33 and 蔚 r of CPC is, the higher the SEM analysis shows, the higher the pressure is, the spallation between the matrix and the functional phase. The optimum molding pressure in this paper is 90 MPA. The optimum process parameters in this paper are as follows: the polarization temperature is 40A 鈩，

本文编号：1400402