Rezende C A, Gouveia R F, da Silva M A, Galembeck F
Institute of Chemistry, University of Campinas-UNICAMP, PO Box 6154, CEP 13083-970, Campinas-SP, Brazil.
J Phys Condens Matter. 2009 Jul 1;21(26):263002. doi: 10.1088/0953-8984/21/26/263002. Epub 2009 Jun 3.
Charge distribution in insulators has received considerable attention but still poses great scientific challenges, largely due to a current lack of firm knowledge about the nature and speciation of charges. Recent studies using analytical microscopies have shown that insulators contain domains with excess fixed ions forming various kinds of potential distribution patterns, which are also imaged by potential mapping using scanning electric probe microscopy. Results from the authors' laboratory show that solid insulators are seldom electroneutral, as opposed to a widespread current assumption. Excess charges can derive from a host of charging mechanisms: excess local ion concentration, radiochemical and tribochemical reactions added to the partition of hydroxonium and hydronium ions derived from atmospheric water. The last factor has been largely overlooked in the literature, but recent experimental evidence suggests that it plays a decisive role in insulator charging. Progress along this line is expected to help solve problems related to unwanted electrostatic discharges, while creating new possibilities for energy storage and handling as well as new electrostatic devices.
绝缘体中的电荷分布已受到广泛关注，但仍面临巨大的科学挑战，这主要是由于目前对电荷的性质和形态缺乏确凿的认识。最近使用分析显微镜的研究表明，绝缘体包含具有过量固定离子的区域，形成了各种电势分布模式，这些模式也可通过扫描电探针显微镜的电势映射成像。作者实验室的结果表明，与目前普遍的假设相反，固体绝缘体很少是电中性的。过量电荷可源自多种充电机制：局部离子浓度过高、放射化学和摩擦化学反应，以及大气水衍生的水合氢离子和水合氢离子的分配。最后一个因素在文献中大多被忽视，但最近的实验证据表明，它在绝缘体充电中起决定性作用。预计在这方面的进展将有助于解决与不必要的静电放电相关的问题，同时为能量存储和处理以及新型静电设备创造新的可能性。
