Modification of silica by an organic monolayer in aqueous medium using octylphosphonic acid and aluminium species

Lassiaz, Stéphanie; Labarre, Dominique; Galarneau, Anne; Brunel, Daniel; Mutin, P. Hubert

doi:10.1039/c1jm10128e

Cited by 20 publications

(27 citation statements)

References 48 publications

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“…20,45 The surface modification was monitored by FTIR and 31 P solid-state NMR spectroscopies, and elemental analysis of the washed and dried NPs. All these molecules are water-soluble at the concentrations used, which for instance is not the case for dodecyl-or octadecylphosphonic acids, discarded for this study.…”

Section: Surface Modification Of Nps With Phosphonic Acidsmentioning

confidence: 99%

“…27 However, it gives no direct information on the exact bonding modes of phosphonate species to the surface, contrary to 17 O MAS-NMR. 20 Note that in aqueous solution, due to the sensitivity of P-O-Si bonds to hydrolysis, 30 the phosphonate species should be grafted via P-O-Al bonds only. 2 show in all cases broad resonances in the 0-35 ppm range.…”

Section: Surface Modification Of Nps With Phosphonic Acidsmentioning

confidence: 99%

“…Owing to the low solubility of these compounds in water and their high sensitivity to hydrolysis, surface modification is in most cases performed in organic medium to avoid anarchic polycondensation of the organotrialkoxysilanes. 20 This offers the possibility to tune the interactions (electrostatic, steric, hydrophobic, etc.) Na and coworkers reported the modification of colloidal silica with methyltrimethoxysilane (MTMS) and g-glycidoxypropyltrimethoxysilane (GTMS).…”

Section: Introductionmentioning

confidence: 99%

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Surface modification of alumina-coated silica nanoparticles in aqueous sols with phosphonic acids and impact on nanoparticle interactions

Pauly

Genix

Alauzun

et al. 2015

Phys. Chem. Chem. Phys.

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It is often necessary to tailor nanoparticle (NP) interactions and their compatibility with a polymer matrix by grafting organic groups, but the commonly used silanization route offers little versatility, particularly in water. Herein, alumina-coated silica NPs in aqueous sols have been modified for the first time with low molecular-weight phosphonic acids (PAs) bearing organic groups of various hydrophobicities and charges: propyl, pentyl and octyl PAs, and two PAs bearing hydrophilic groups, either a neutral diethylene glycol (DEPA) or a potentially charged carboxylic acid (CAPA) group. The interactions and aggregation in the sols have been investigated using zeta potential measurements, dynamic light scattering, transmission electron microscopy, and small-angle scattering methods. The surface modification has been studied using FTIR and (31)P MAS NMR spectroscopies. Both high grafting density ρ and high hydrophobicity of the groups on the PAs induced aggregation, whereas suspensions of NPs grafted by DEPA remained stable up to the highest ρ. Unexpectedly, CAPA-modified NPs showed aggregation even at low ρ, suggesting that the carboxylic end group was also grafted to the surface. Surface modification of aqueous sols with PAs allows thus for the grafting of a higher density and a wider variety of organic groups than organosilanes, offering an increased control of the interactions between NPs, which is of interest for designing waterborne nanocomposites.

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Section: Surface Modification Of Nps With Phosphonic Acidsmentioning

confidence: 99%

Section: Surface Modification Of Nps With Phosphonic Acidsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Surface modification of alumina-coated silica nanoparticles in aqueous sols with phosphonic acids and impact on nanoparticle interactions

Pauly

Genix

Alauzun

et al. 2015

Phys. Chem. Chem. Phys.

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“…This is supported by the sharp peaks in the 31 P spectrum, which were identified as a sign for crystalline aluminum alkylphosphonate. [24][25]51 Sample A1 still has a high content of imogolite and the new octahedral Al environment is less well defined. Furthermore, the 31 P spectrum shows a broad peak, which was identified by Lassiaz et al as an indicator for a successful grafting reaction on aluminum oxide.…”

Section: Mas Nmrmentioning

confidence: 99%

Partial Transformation of Imogolite by Decylphosphonic Acid Yields an Interface Active Composite Material

et al. 2019

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The phosphonic acid moiety is commonly used as an anchoring group for the surface modification of imogolite. However, the impact of the reaction on its structure has never been clearly analyzed before.We study the reaction of imogolite and decylphosphonic acid by combining infrared spectroscopy, X-ray scattering, scanning electron microscopy, transmission electron microscopy and solid-state nuclear magnetic resonance spectroscopy. Instead of a surface functionalization, we observe the formation of a lamellar phase interconnected with imogolite bundles. Although we find no evidence for grafted imogolite tubes, we observe the expected dispersion characteristics and stabilization of water in toluene emulsions described in literature. Based on the surface chemistry of imogolite we propose an explanation for the observed reactivity and link the structural features of the obtained composite material to its dispersibility in toluene and its observed properties at the toluene-water interface.

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“…Examining the CBET parameter provides an additional information. This parameter is related to the affinity of N2 for sorbent and can be used to compare the hydrophilic/hydrophobic character of pore surfaces for closely-related materials, such as hybrid silica-based systems [31][32][33]. In this context, the pure silica matrix with the highest CBET value (CBET = 110) was the more hydrophilic, followed by the APTMSmodified one (CBET = 90) whereas ETES had the more hydrophobic surface (CBET = 50).…”

Section: Characterization Of the Hybrid Matricesmentioning

confidence: 99%

Optical microalgal biosensors for aqueous contaminants using organically doped silica as cellular hosts

et al. 2017

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Optical biosensors for the detection of toxic species in aqueous media were developed via the encapsulation of microalgae in sol-gel matrices. In a first step, the effect of cadmium(II), lead(II), and anthracene on the chlorophyll a fluorescence intensity of Anabaena flos-aquae, Chlorella vulgaris, and Euglena gracilis microalgae in suspension was studied. Complementary ATP-metry measurements demonstrated a direct relationship between optical response and pollutant toxicity, in a cell- and dose-dependent manner. In a second step, microalgae were successfully encapsulated in silicate-colloidal silica nanocomposite matrices. However, a complete loss of cell response to pollutant addition was observed, despite the preservation of cell viability. Introduction of a low amount (5 mol%) of amine- or ethyl-bearing silanes in the matrix formulation allowed the recovery of the sensing capacity of the immobilized microalgae, without impacting on the response time (30 s). Porosimetry and Si solid-state NMR spectroscopy showed that the organic moieties are fully integrated into the inorganic network, tuning the ability of the target pollutant to diffuse and reach the encapsulated algae. This versatile strategy could be useful for the easy and fast assessment of contamination levels in polluted waters. Graphical Abstract Microalgal biosensors for aqueous contaminants using organically doped silica as cellular hosts.

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Modification of silica by an organic monolayer in aqueous medium using octylphosphonic acid and aluminium species

Cited by 20 publications

References 48 publications

Surface modification of alumina-coated silica nanoparticles in aqueous sols with phosphonic acids and impact on nanoparticle interactions

Surface modification of alumina-coated silica nanoparticles in aqueous sols with phosphonic acids and impact on nanoparticle interactions

Partial Transformation of Imogolite by Decylphosphonic Acid Yields an Interface Active Composite Material

Optical microalgal biosensors for aqueous contaminants using organically doped silica as cellular hosts

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