tailieunhanh - Effect of some dispersing auxiliaries on nanosilica dispersion into passive chrome trivalent solution

The obtained results indicated that passive Cr(III)-nanosilica solution after 7-day fabrication was uniform, having no agglomeration if using SDS, PVP and AE7 agent. AE7 saw the best dispersion aid ability for dispersing nanosilica into passive Cr(III) solution in those dispersing auxiliaries studied. Conversion coating fabricated from passive Cr(III)-nanosilicaAE7 solution had a highest level of anticorrosion durability. | Tạp chí Khoa học và Công nghệ 54 (3) (2016) 377-385 DOI: EFFECT OF SOME DISPERSING AUXILIARIES ON NANOSILICA DISPERSION INTO PASSIVE CHROME TRIVALENT SOLUTION Truong Thi Nam1, *, Hoang Thi Huong Thuy3, 4 , Dao Phi Hung1, Le Ba Thang1, Nguyen Thi Cam Ha2 1 Institue for Tropical Technology, VAST, 18 Hoang Quoc Viet, Cau Giay, Ha Noi 2 3 Faculty of Chemistry, VNU University of Science, 19 Le Thanh Tong, Ha Noi Faculty of Chemistry, Ha Noi University of Education, 136 Xuan Thuy, Cau Giay, Ha Noi 4 Hong Duc University, 565 Quang Trung, Thanh Hoa city, Thanh Hoa * Email: namtruong1208@ Receited: 28th August 2015; Accepted for publication: 29 March 2016 ABSTRACT Effect of dispersing auxiliaries, namely polyvinylpyrrolidone (PVP), Lauryl dodecyl sulfate sodium (SDS), nonionic surfactant op-10 (Op-10), C12-14 alcohol ethoxylate AE7 (AE7) and polyethylenimine (epomin) on the nanosilica dispersion into passive Cr(III) solution, pH = , were investigated by FT-IR, zeta potential, particle-size distribution and natural salt spray testing. The obtained results indicated that passive Cr(III)-nanosilica solution after 7-day fabrication was uniform, having no agglomeration if using SDS, PVP and AE7 agent. AE7 saw the best dispersion aid ability for dispersing nanosilica into passive Cr(III) solution in those dispersing auxiliaries studied. Conversion coating fabricated from passive Cr(III)-nanosilicaAE7 solution had a highest level of anticorrosion durability. White rust appeared on X-Cut position of sample fabricated from former solution after 9-day natural salt spray testing, which was the longest in all of samples. However, average particle size of nanosilica in passive Cr(III)nanosilica-AE7 solution was approximately 60 nm, which was quintuple initial average nanosilica size. Hence, AE7 could help nanosilica dispersion into passive Cr(III) solution but effect of AE7 was not strong enough to disperse nanosilica well into solution