Evaluation of the effective parameters in synthesis of the nano-structured scaling inhibitors applicable in oil fields with sea water injection process

摘要

Nano-structured calcium-diethylenetriaminepenta(methylenephosphonate) (Ca-DTPMP), a mineral scale inhibitor, is prepared in an aqueous reaction media using, as cationic surfactant CTAB. The aim of the present study is to determine effects of specific factors such as pH, sonication and the concentrations of the surfactant, calcium and DTPMP on the crystallite size, particles size distribution, shape and morphology. The physical characteristics of the prepared nanoparticles are investigated by X-ray diffraction and high-resolution scanning electron microscopy analyses in which the range of the particle size is 91–166 nm. The results show that more dispersed, homogenous size, separable and fine nanoparticles of the Ca-DTPMP are prepared at higher pH values. The size and morphology of the produced Ca-DTPMP, become more favourable with the increase of the CTAB/Ca molar ratio up to a threshold value, which exceeded leads to their decline. The study of the calcium and DTPMP concentrations effects on the Ca-DTPMP synthesis, show that the fine and well dispersed spherical Ca-DTPMP nanoparticles are produced by either increasing calcium concentration or decreasing of the DTPMP concentration. Instead, if the Ca/DTPMP molar ratio is fixed, the same particle properties are observed. The sonication treatment causes a size increase of the particles that reduces their agglomeration and thus improves the particles dispersion.