Ultra-high surface area nano-porous silica from expanded perlite: Formation and characterization

Direct-Continuous Preparation of Nanostructured Titania-Silica Using Surfactant-Free Non-Scaffold Rice Starch Template

“…Furthermore, the Brunauer-Emmett-Teller (BET) surface area for SiNS has been experimentally determined to be 538.74 m 2 ·g −1 . The specific surface area obtained is considerably higher than most natural porous materials such as clay (10 to 100 m 2 ·g −1 ) and activated graphite (<200 m 2 ·g −1 ) [ 37 , 38 ]. To compare with other synthetic porous silica materials, the surface area obtained from this method is also higher; Wu et al (127 m 2 ·g −1 ), Affandi et al (152 m 2 ·g −1 ), and Wei et al (455 m 2 ·g −1 ) [ 22 , 39 , 40 ].…”

“…The total accessible micropore volume present can be regarded as the adsorption space; the process by which this occurs is due to the micropore filling, in accordance to IUPAC definition, which is distinct from surface coverage, and which takes place on the wall of open macropore or mesopore. It is worthy of note that different plots such as Barrett, Joyner and Halenda method (BJH), the Micropore (MP) Method, Density Functional Theory (DFT), Dubinin Plots, and Horvath-Kawazoe (H-K) calculations are widely reported to determine the effective pore size distributions [ 36 , 37 , 38 ]. In this study, BJH models were calculated in satisfactory fit for SiNS to have an average pore diameter of 1.6 nm, as shown in Figure 7 b.…”

A Sustained Release Anchored Biocide System Utilizing the Honeycomb Cellular Structure of Expanded Perlite

“…The EP surface terminator groups in this study could be either silanols, which occur in disordered amorphous silica, 30 or exchangeable cation sites of the type that occur in ordered zeolite channel surfaces. 50 In the absence of definitive evidence, the disordered nature of EP 9 has encouraged us to assume the silanol terminator group species. This assumption is supported by the insensitivity of pH, which remains in the region 7.0−7.4 during EP immersion in water over 14 h. This argues in favor of neutral surface silanols and against the presence of exchangeable alkali cation sites of the type found in zeolite minerals, which would have increased solution alkalinity as a result of aqueous Na + dissociation.…”

“…The role of surface area and oxide surface composition in the uptake of AQAS into the cells of EP has been explored. Previous studies 9 have reported a new related material extracted from pristine EP by aqueous alkali. BET N 2 surface areas for the alkali-modified EP materials are observed to be ca.…”

“…5 Recent studies have shown that these expanded perlites exhibit an average surface area of 1−2 m 2 g −1 , 6−8 and they can be chemically transformed into a high surface area amorphous silica of unusually high surface area (740 m 2 g −1 ). 9 The unusual properties of EP (viz., lightweight, thermal stability, and chemical inertness) also make it a candidate for applications across a range of fields and sectors. However, EP has received comparatively little attention in the industrial, biology, or surface chemistry literature, compared to other synthetic porous oxides such as amorphous or encapsulating silica.…”