The average pore size is 3.7 nm (larger than the 2.35-nm size of TBOS-based silica fibers),

and surface area is 475 m2/g. In view of these outcomes, self-assembly Selleck BVD-523 using TEOS in quiescent conditions yields a mesoporous structure with disordered pore arrangement as verified by TEM imaging (Figure 8b). Spots possessing long nonconnecting channel that resulted from wormlike micelles can be observed (Figure 8c). TEOS in the presence of Cl− counterion causes elongation of the short cylindrical micelles of the surfactant into long wormlike micellar templates. However, this combination does not induce ordering of these micelles upon silica condensation. A similar morphology was obtained for the quiescent condensation of TEOS in the presence of HNO3 (sample selleck inhibitor MS6b). The gyroidal product (Figure 9a) possesses a slightly better pore arrangement, indicated by the sharper (100) reflection in the XRD pattern (Figure 7b), but has inferior surface area properties (Table 2). In mesoporous structure growth, it is known that the self-assembled silica-micelles species undergo further condensation and structuring (pore ordering) steps that dictate the final shape and structure. The better order can be related to a better packing of surfactant micelles under nitric acid compared to HCl which goes in line with the Hofmeister binding strength, NO3 − > Cl−,

so there are more attraction and formation of self-assembled species. However, subsequent restructuring was slower for HNO3 than for HCl as indicated by inferior structural properties (smaller pore width and surface area). Long wormlike pores are still seen in the TEM image (Figure 9b) and apparently extend over the curvature and surface texture of the product. The repetition of this structure, regardless of the acid type, Selleck SIS3 stresses the role of TEOS in elongating the wormlike micelles under quiescent conditions. It is known in mixed systems that cationic surfactants can grow long under some conditions favoring the reduction of end-cap energy of the rod micelles [48, 49]. Figure 9 SEM (a) and TEM (b) images of sample MS6b prepared using TEOS and HNO 3 . The general behavior cAMP is that TEOS

under quiescent conditions yields mesoporous gyroidal shapes in the water bulk with lower pore order and structure quality than TBOS. The key difference lies in the speed of condensation and the simultaneous pore structuring steps. As described before, TEOS is less hydrophobic, so it can diffuse from the top layer into the water phase faster than TBOS. This was clearly reflected by the shorter induction time. Thus, in the absence of mixing, TEOS can be available more readily in the water phase than TBOS and hence speeds up the condensation, yielding products mostly in the bulk of water phase. Particle aggregation was noticed but not in well-defined shapes. Simultaneous pore structuring was ineffective or even absent as reflected by the lower degree of order.