摘要本论文使用分子动力学(MD)模拟工业循环冷却水五种常用有机膦系化合物:氨基二亚甲基膦酸(NDP)、氨基三亚甲基膦酸(NTMP)、乙二胺四亚甲基膦酸(EDTMP)、己二胺四亚甲基膦酸(HDTMP)和二乙烯三胺五亚甲基膦酸(DTPMP)的阻垢作用机理。对阻垢剂和碳酸钙晶型的相互作用结果表明, 目标分子与方解石表面形成了较强的吸附作用。从结合能数据来看,主要是静电相互作用占主导,影响远大于范德华作用力。总的结合能表明,阻垢作用的有机膦分子对碳酸钙垢的强弱是 DTPMP>HDTMP>EDTMP>NTMP>NDP。发现膦酸基团的数目越多,相对结合能越大,即表明阻垢效果越好。相同个数膦酸基团的阻垢剂分子,碳链越长,效果相对较佳。从相互作用细节可以看出, 钙离子与晶体表面膦酸基团的氧原子形成强烈的静电相互作用,占据了原本游离态CO32-在晶面上的活性生长空间,阻碍了晶格的正常生长,从而抑制了晶体的形成。同时,测定了O 原子和晶体表面的 Ca2+之间的有效距离,发现与实际中的 Ca-O 离子键长相接近,推断添加的阻垢剂与晶面间形成了 Ca-O 离子键。同时,比较具有不同的晶体表面结合能膦酸分子,他们的结合能,晶面更不稳定,更容易发生晶格转换,成长更快。58198
毕业论文关键词:循环冷却水;有机膦分子;阻垢机理;分子动力学
Abstract In this paper, the use of molecular dynamics (MD) simulation of industrial circulatingcooling water five kind of commonly used organophosphorus compounds: diaminomethylene diphosphate (NDP), amino trimethylene phosphonic acid (NTMP),ethylenediamine tetramethylene phosphoric acid (EDTMP) and hexamethylene diaminetetramethylene phosphate HDTMP and ethylene triamine pentamethylene phosphate(DTPMP)scale inhibition mechanism.The interaction of scale inhibitor and calcium carbonate crystal form showed that thetarget molecule and the calcite surface formed a strong adsorption. From the bindingenergy data, the main electrostatic interaction is dominant, the impact is much greater thanthe Fan Dehua force. The total binding energy showed that the scale inhibition effect oforganic phosphate molecules on the strength of calcium carbonate scale is DTPMP >HDTMP > EDTMP > NTMP > > NDP. The more the number of phosphate groups is found,the greater the relative binding energy is, the better the scale inhibition effect is. The samenumber of scale inhibitor molecules, the longer the carbon chain, the effect is relativelygood. From the interaction details can be seen, the oxygen atom of the calcium ions and thesurface of the crystal phosphate groups formed strong electrostatic interaction, occupy theoriginally free state CO32-on the crystal surface active growth space, hinder the normalgrowth of lattice, thus inhibiting the formation of crystal. At the same time, the effectivedistance between the O atom and the surface of the crystal was measured. It was found thatthe Ca2+ ion Jian Changxiang was close to the actual Ca-O ion, and the Ca-O ion bondformed between the crystal surface and the inhibitor added.The main growth surface of the target molecule and the CaCO3 crystal was studied bythe same method and condition. The results showed that the other 4 molecules except NDPcould be in different degrees with the CaCO3 crystal form. Obtained according to amodified merge data and phosphate molecules on CaCO3 scale inhibition action of strongDTPMP > HDTMP > EDTMP > NTMP > NDP. at the same time, compared with differentcrystal surfaces with phosphoric acid molecules, the binding energy, crystal face more unstable, more prone to lattice conversion, grow faster.
Keywords: circulating cooling water; an organic phosphorus molecules; inhibitionmechanism; molecular dynamics
目录
第一章绪论1
1.1课题研究的意义-1
1.2工业循环冷却水系统-1 含N有机膦系阻垢剂与碳酸钙相互作用的MD研究:http://www.youerw.com/huaxue/lunwen_63188.html