Effect of Piperazine Functionalization of Mesoporous Silica Type SBA-15 on the Loading Efficiency of 2-Mercaptobenzothiazole Corrosion Inhibitor

Abstract

This work intends to study the effect of functionalization of SBA-15 on the loading and release behaviors of 2-mercaptobenzothiazole (MBT). SBA-15 mesoporous silica was first synthesized and functionalized by a postgrafting method using a piperazine silane coupling agent. Then, SBA-15 was loaded with MBT as a corrosion inhibitor. Various characterizations demonstrated that MBT was successfully encapsulated into the interior nanochannels of nanocontainers. Furthermore, the release study results revealed that the modified sample liberated MBT up to 17 times of the unmodified sample. Assessment of the electrochemical behavior of steel in NaCl solution containing the released inhibiting moieties indicated that the presence of MBT resulted in the formation of a more compact layer of corrosion products with more fine particles. Moreover, the MBT molecules were found to be mixed-type corrosion inhibitors. It was found that functionalizing by piperazine improved the inhibition efficiency of MBTloaded samples. The trend and magnitude of impedance of specimens coated by the artificially scratched epoxy silicone revealed the role of the inhibitors desorbed from the functionalized SBA-15 in the polymer film active corrosion protection properties.

Adaptive Coatings with Anticorrosion and Antibiofouling Properties

“…2-MBT was selected as inhibitor because it showed good inhibition properties against corrosion of steel. [74,78,79] MBT was linked to the copolymers via disulfide bonds, so that the inhibitor can be released upon reduction. The functional monomer (MBTS 2 MA) was synthesized via a thiol-disulfide interchange reaction between 2,2′-dibenzothiazolyl disulfide (BSSB) and 2-mercaptoethanol, followed by an esterification with methacrylic anhydride (MAAn) (Figure 1a; Figure S1a, Supporting Information for the 1 H NMR spectrum).…”

Mesoporous silica nanoparticles as carriers of active agents for smart anticorrosive organic coatings: a critical review

“…-Hexagonal, such as the "Mobil Composition of Matter number 41" (MCM-41), 52,57 "Santa Barbara Amorphous type number 15" (SBA-15) [67][68][69] or "Folded Sheets Mesoporous material number 16" (FSM-16); 70 -Cubic, such as MCM-48; 71,72 -Lamellar, such as MCM-50; 73 -Other random structures, 74 such as the "Technische Universiteit Delft number 1" (TUD-1), 75 the "Hiroshima Mesoporous Material number 33" (HMM-33) 76 and the "Michigan State University type number 1" (MSU-1). 77 In Table 1 the different mesostructures and textural properties of the above mentioned MSN are summarized.…”

“…The development of surface modified MSN is a widely exploited approach to optimize the loading and modulate the corrosion inhibitor release, and it may interest the internal surface of the pores and/or their edges. The MSN decoration can be operated during the MSN synthesis 122,123 or after the synthesis 52,[54][55][56][58][59][60]69,124 and, in some cases, after the corrosion inhibitor loading or grafting. 57,125 Surface modification is generally operated through organosilanes, that can easily react with the MSN surface.…”

“…Ashrafi-Shahri et al 55 functionalized MSN with APTES and, in a second step, with FeCl 3 , in order to graft the corrosion inhibitor Eriochrom Black T (EBT, C 20 H 12 N 3 O 7 SNa). Amini et al 69 functionalized MSN with piperazine, in order to improve the MBT capability to load the mesopores.…”

“…They also observed that the maximum corrosion inhibitor release in corrosive environments is reached, after about 5 hours, due to both the solubility of MBT in the solution and the MBT degradation to sub-products, such as 2-hydroxybenzothiazole and benzothiazole. 51,104,113 With a different approach, Amini et al 69 promoted the MBT release in neutral and alkaline conditions by exploiting the interaction between MBT with piperazine, previously grafted onto the MSN surface. A pH controlled release of 8-HQ from MSN was designed by Shchukina et al 106 and Shi et al, 68 which demonstrated the stability of these nanocontainers at neutral and slightly acid or basic pH and the corrosion inhibitor release in stronger acid and alkaline environment.…”