It is for the first time demonstrated that the plugged hexagonal-templated silicas can be facilely and controllably prepared from cheap sodium silicate without using any additives. The formation of constricted/plugged mesostructures is attributed to the non-uniform/ill-templating behaviours between silicate oligomers and P123 molecules under the synthesis conditions employed.

A facile and versatile synthesis method, called the partitioned cooperative self-assembly process (PCSA process), is developed to prepare mesoporous SBA-15 silicas using P123 surfactant as template and cheap sodium silicate (SS) as silica precursor. It is demonstrated for the first time that by simply partitioning the cooperative self-assembly process, larger mesopore size (∼10 nm) can be achieved without using any additives or special synthetic conditions; high microporosities (>0.15 cm³ g⁻¹) unprecendentedly persist upon hydrothermal treatment at 120 °C for 20 h with comparable mesopore sizes, which are in big contrast with those prepared by conventional method. The PHTS-type SBA-15s can also be favorably prepared by the PCSA process. In addition, the sizes of flower-like SBA-15 particle can be facilely tuned by adjusting the addition combinations of SS and interval time between the 1st and 2nd additions in the PCSA process. Interestingly, based on TEOS, the PCSA process yielded bimodal mesostructured SBA-15 with different wall thicknesses but the same mesopore size. The versatile PCSA process, which has shown its potential in tailoring the textural and morphological properties of SBA-15s, could lead to even wider spectrum of SBA-15s with various mesostructures if coupled with other synthetic measures.

This work for the first time demonstrated that hierarchically meso–mesoporous silicas can be facilely prepared in a simple ternary non-ionic surfactant templating system (TEOS/HCl(aq.)/P123) based on a previously reported partitioned cooperative self-assembly (PCSA) principle. As a result, unique clew-like hierarchically meso–mesoporous (HMM) silica particles with the first mode of worm-like mesostructures (3D-interconnected wormholes with pore size of 7–10 nm) and the second mode of 3D-interconnected intra-particulate mesochannels (16–32 nm in sizes) can be obtained in a controllable way without resorting to complicated synthesis procedures or special additives or multi-templates. Associated with the large mesopore sizes in both modes, very large mesoporosity (up to 2.37 cm³ g⁻¹) can be achieved. Based on systematic investigations on the synthesis conditions, synthesis domains for preparation of such HMM silicas were also presented. It is proposed that the formation of two mode mesoporosities follows different mechanisms: the first mode mesoporosity results from the self-assembly between P123 and silicate, though it is shown to be disordered due to the partitioning effect, while the formation of the second mode mesoporosity starts from loosely packed silicate/P123 hybrid aggregates/flocs formed upon the 1^st addition of TEOS, and then is initiated and finished by the 2^nd TEOS addition. This synthesis protocol therefore constitutes a new, simple and reliable pathway to prepare HMM silicas.

In this work, hierarchically porous SiC ceramics were prepared via the foaming method. Porous ceramics with tunable, uniform, and bimodal pore structures were successfully fabricated in a facile way. The formation mechanisms of the 1st and 2nd modal macropores are the H₂O₂ foaming process and SiC particle overlap, respectively. The effect of pore-foaming agent amount, foaming temperature, and surfactant was investigated. According to the results, with increasing H₂O₂ amount, the porosity, pore size, and interconnectivity of the 1st modal pores increased, whereas bulk density and strength decreased. The porosity increased while the strength decreased as the foaming temperature increased. Surfactants increased pore interconnectivity and porosity. When the foaming temperature was 85 °C, and the addition of H₂O₂ was 5 wt.%, the porosity, bulk density, flexural strength, and compressive strength were 56.32%, 2.8301 g/cm³, 11.94 MPa, and 24.32 MPa, respectively. Moreover, SiC porous ceramics exhibited excellent corrosion resistance to acids and alkalis.

Through a high-temperature and water-based EISA (HW-EISA) approach, mesoporous TiO₂ with high surface areas, ultra-large mesopores/pore volumes and tuneable bi-crystallinity (anatase plus rutile) can be facilely prepared in a ternary templating system (peroxotitanic acid/P123/H₂O).