Adsorption and wetting characterization of hydrophobic SBA-15 silicas

Bernardoni, Frank; Fadeev, Alexander Y.

doi:10.1016/j.jcis.2011.01.033

Cited by 44 publications

(23 citation statements)

References 53 publications

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“…There is a growing interest in the adsorption chemistry of ordered meso-porous silica (SBA-15) in relation to organic pollutants (Bernardoni and Fadeev, 2011). This interest stem from the fact that SBA-15 meets most criteria for selection of adsorbents: sorption capacity, selectivity, regenerability, kinetics, compatibility, and cost.…”

Section: Introductionmentioning

confidence: 99%

Microscale scavenging of pentachlorophenol in water using amine and tripolyphosphate-grafted SBA-15 silica: Batch and modeling studies

Diagboya

Olu-Owolabi

Adebowale

2014

Journal of Environmental Management

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a b s t r a c tMesoporous silica SBA-15 meets most criteria for selection of water treatment adsorbents such as high specific surface area, large pore-size, chemical inertness, repertory of surface functional groups, good thermal stability, selectivity, regenerability, and low cost of manufacture. However, its use for water treatment is still largely unexplored. SBA-15 and its functionalized derivatives of aminopropyltriethoxysilane (SA) and tripolyphosphate (ST) were synthesized, characterized, and used to investigate pentachlorophenol (PCP) removal from aqueous solutions. Functionalization improved SBA-15 capacity for PCP removal from solution in accordance with the trend SBA-15 < ST < SA. Sorption rate experiments data fit the Lagergren pseudo-second order kinetics model. Intra-particle diffusion indicated that the sorption is controlled by two mechanisms: intra-particle and equilibrium diffusion. Adsorptive pore-filling and electrostatic interactions were implicated in the removal of PCP from solution. Electrostatic interaction led to !75% increase in sorption upon functionalization. The equilibrium sorption data of the PCP on these mesoporous materials fits the Freundlich isotherm. Desorption hysteresis was low for the pristine SBA-15, but the functionalized SBA-15 materials showed higher hysteresis. The results imply that functionalized SBA-15 sorbents are promising materials for microscale scavenging of PCP in solution.

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Section: Introductionmentioning

confidence: 99%

Microscale scavenging of pentachlorophenol in water using amine and tripolyphosphate-grafted SBA-15 silica: Batch and modeling studies

Diagboya

Olu-Owolabi

Adebowale

2014

Journal of Environmental Management

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“…Moreover, if we compare the reduction of the pore size and the length of the 3-aminopropylsilanetriol molecule, for some samples, the reduction of the pore size is twice the size of the molecule. With these considerations in mind, a closely packed monolayer of organic molecules could have been formed on the silica surface for samples A2 and A3.However, the possibility of cross-linking and polymeric deposition makes difficult to obtain a definitive conclusion regarding the packing density based on the grafting density data and the molecule length alone[54]. Another possible calculation is the estimation of the theoretical pore volume.…”

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confidence: 99%

A new sustainable route in supercritical CO2 to functionalize silica SBA-15 with 3-aminopropyltrimethoxysilane as material for carbon capture

Sánchez-Vicente

Stevens

Pando

et al. 2015

Chemical Engineering Journal

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“…[66] Although rigorous interpretation of the C constant is limited due to the approximate nature of the BET model, lower C constant values in a material generally correlate to lower average surface energy. [69] The C constant of the Et-CNMO films was 90 ± 10 (average measurement of five different samples of ethylene-bridged films). [67][68][69] For mesoporous SBA-15 silica, the dimensionless C constant is typically between 100 and 150, indicating the high energy, polar surfaces of surface silanol groups.…”

Section: Surface Properties and Pore Structure Within The Organosilicmentioning

confidence: 99%

“…Previous research has shown that BET C constants can be used to qualitatively provide information about the polarity of the external and porous surfaces of silica materials. [69] The rate of diffusion of absorbed water was also measured for the Hex-CNMO films and compared to the rate of diffusion of absorbed water of organosilica samples that have been previously reported in literature. [69] The C constant of the Et-CNMO films was 90 ± 10 (average measurement of five different samples of ethylene-bridged films).…”

Section: Surface Properties and Pore Structure Within The Organosilicmentioning

confidence: 99%

Iridescent Chiral Nematic Mesoporous Organosilicas with Alkylene Spacers

Terpstra

Arnett

Manning

et al. 2018

Advanced Optical Materials

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surfactants and inorganic precursors, it has been possible to create mesoporous materials with different symmetries and pore sizes, and diverse compositions. [5,8] For example, using chiral surfactants as a liquid crystal template has created chiral mesoporous materials with twisted helical structures. [13] In 1999, three research groups independently reported on the incorporation of organic groups into mesoporous silica by using (R′O) 3 SiRSi(OR′) 3 precursors in the place of Si(OR) 4 precursors for the sol-gel condensation. [7,9,14] It proved possible to construct periodic mesoporous silica with organic groups directly integrated into the walls of the mesoporous structure. [11,[15][16][17][18][19][20][21][22][23] Sol-gel processing of silicate materials is highly versatile-it can incorporate various types of precursors and can be carried out under a variety of reaction conditions (e.g., variable pH, temperature, concentration, and solvent mixtures). [24] Therefore, mesoporous organosilica materials have attracted increasing interest for applications including catalysis, [1,25] metal scavenging, [26] chromatography, [27] and biomedical applications. [2] Cellulose nanocrystals (CNCs) obtained from sulfuric-acidcatalyzed hydrolysis of biomass are remarkable materials. [28,29] In 1951, Rånby isolated the crystalline regions within plant cellulose microfibers to form colloidal CNCs with nanoscale dimensions. [28] CNCs have impressive mechanical properties that arise from their high crystallinity and large aspect ratios. [30] Remarkably, CNCs also form a chiral nematic liquid crystal in water. [31] This order can be retained upon drying the aqueous suspension to give a colored, iridescent film. [32] The CNCs arrange into a Bouligand structure, where the crystallites themselves are aligned in layers, but twist with a characteristic helical pitch, P. It is the repeating helicoidal structure that leads to diffraction of circularly polarized light from the CNC films. [33] Many researchers are making new materials that take advantage of the unique properties of CNCs. [30,[34][35][36][37][38][39][40][41][42][43][44][45][46][47] In 2010, we discovered that films of mesoporous silica with chiral nematic structure could be prepared using CNCs as a template. [20] When Si(OR) 4 is condensed with CNCs in water, the resulting composite film contains silica and a chiral nematic assembly of CNCs. CNCs can be removed from the composite materials using pyrolysis, leaving behind thin films of iridescent mesoporous silica with a chiral nematic arrangement of pores inside the glass. These materials are of interest Mesoporous organosilica films with chiral nematic structures are prepared with a bridging urea group and with alkylene bridges, where the length of the alkylene bridge varies from C 1 -C 6 . To synthesize these materials, cellulose nanocrystals (CNCs) are used as liquid crystal templates, which coassemble with the organosilica precursor to give composite materials with a chiral nematic structure of CNCs embedded within. Remova...

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Adsorption and wetting characterization of hydrophobic SBA-15 silicas

Cited by 44 publications

References 53 publications

Microscale scavenging of pentachlorophenol in water using amine and tripolyphosphate-grafted SBA-15 silica: Batch and modeling studies

Microscale scavenging of pentachlorophenol in water using amine and tripolyphosphate-grafted SBA-15 silica: Batch and modeling studies

A new sustainable route in supercritical CO2 to functionalize silica SBA-15 with 3-aminopropyltrimethoxysilane as material for carbon capture

Iridescent Chiral Nematic Mesoporous Organosilicas with Alkylene Spacers

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