As C is a light element, it cannot be detected by EDS. Considering both the Raman results (Figure 2) and the SEM images (Figure 3), the branched samples were shown to consist of ACC nanoparticles and mesoporous NOD-like receptor inhibitor silica gel. Namely, the structure of the resulting silica gel was successfully tailored to be mesoporous, which

allows the existence of a stable ACC phase. Anlotinib price Figure 3 SEM images. (a) product with flower-like structure; (b) area 1 of (a) with high magnification; (c) area 2 of (a) with high magnification; (d) EDS spectrum of obtained flower-like product. The ACC phase is usually the transient precursor of calcite [1], vaterite [2], or aragonite [4]. It is difficult to obtain stable ACC in the laboratory because of the large interfacial energy. According to the LSCM and SEM observations, a possible self-assembly process for the branched products is proposed, as illustrated in Figure 4. First, the hydrolysis and polycondensation reactions of ethyl silicate in an alkaline medium MLN2238 in vivo result in silica alcogel after

stirring for 1 h. Second, by adding CaCl2 and urea solutions, ion pairs of Ca2+ and CO3-, which are prenucleation clusters for ACC aggregation [21–23], are formed in the solution. Third, when the mixed solution of CaCl2, urea, and, the silica alcogel is dried under a mild thermal treatment, namely, baking at 60°C, a mesoporous gel is obtained [9] and at the same time, ACC aggregates are entrapped in the silica gel voids, which has been demonstrated by SEM observation of the composites of fibrous silica gel and ACC (Figure 3). The mesoporous silica supports lower

the ACC interfacial energy so that a composite of mesoporous silica gel and stable ACC is formed. Moreover, it can be seen that the ACC nanoparticles are aggregated in an oriented fashion so the branched morphology Etofibrate of the composites appears, as shown in Figure 1. Figure 4 Schematic of possible self-assembly process for branched products. Conclusions In this work, the possibility of synthesizing stable ACC supported by mesoporous silica gel has been described. These composites are obtained using the reaction of CaCl2 and (NH2)2CO in a silica gel medium that is prepared through the hydrolytic polycondensation of ethyl silicate. LSCM, Raman, and SEM observations show that the morphology of the composites, which are composed of ACC nanoparticles and mesoporous silica gel takes on a branched form with cruciform-like and flower-like structures. The growth mechanism is discussed and a possible self-assembly process for the branched products is proposed. Silica gel with 3D-matrix morphology was successfully fabricated as a support for ACC. As a result, chemical agents with 3D-matrix morphology, such as silica gel, have the potential to significantly improve the utility and integrity of underground reservoirs for ACC storage.