Surface chemistry of SiO2 and TiO2–SiO2 glasses as determined by titration of soot particles

Sabia, Robert; Ukrainczyk, Ljerka

doi:10.1016/s0022-3093(00)00237-4

Cited by 31 publications

(23 citation statements)

References 11 publications

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“…40-42, 50, 51 However, the actual density of ionizable sites strongly depends on the nature of the material and could vary within the range of microcoulombs to a few hundreds of millicoulombs per squared meter of a surface. 42,[52][53][54][55] The system of differential equations (1) and (2) was solved with appropriate boundary conditions (see section SI-1 and Table S1, Supporting Information), for a particular V and assuming flux conservation in a first step (eq. 3)…”

Section: Resultsmentioning

confidence: 99%

Simultaneous Nanoscale Surface Charge and Topographical Mapping

et al. 2015

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Nanopipettes are playing an increasingly prominent role in nanoscience, for sizing, sequencing, delivery, detection and mapping interfacial properties. Herein, the question of how to best resolve topography and surface charge effects when using a nanopipette as a probe for mapping in scanning ion conductance microscopy (SICM) is addressed. It is shown that using a bias modulated (BM) SICM scheme it is possible to map the topography faithfully, while also allowing surface charge to be estimated. This is achieved by applying zero net bias between the electrode in the SICM tip and the one in bulk solution for topographical mapping, with just a small harmonic perturbation of the potential to create an AC current for tip positioning.Then a net bias is applied, whereupon the ion conductance current becomes sensitive to surface charge. Practically this is optimally implemented in a hopping-cyclic voltammetry mode where the probe is approached at zero net bias at a series of pixels across the surface to reach a defined separation, and then a triangular potential waveform is applied and the current response is recorded. Underpinned with theoretical analysis, including finite element modeling of the DC and AC components of the ionic current flowing through the nanopipette tip, the powerful capabilities of this approach are demonstrated with the probing of interfacial acid-base equilibria and high resolution imaging of surface charge heterogeneities, simultaneously with topography, on modified substrates.

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Section: Resultsmentioning

confidence: 99%

Simultaneous Nanoscale Surface Charge and Topographical Mapping

et al. 2015

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“…The latter step is considered to be sensitively depending on the configuration of terminating groups on the silica surface, since such surface groups obviously provide the reducing radicals required for the reduction of metal ions. Terminating OH-groups usually formed on the oxide surface by dissociative adsorption of water molecules can acquire such properties, depending on their coordination symmetry [8]. Accordingly, metal ion reduction could proceed via the reaction:…”

Section: Methodsmentioning

confidence: 99%

Formation and Characterization of Gold and Silver Nanoparticles on Silica Nanospheres

Miclea

Hofmeister

2004

Molecular Crystals and Liquid Crystals

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Novel optical effects are expected by appropriately arranging metal nanoparticles on the surface of spherical insulating materials. Optical resonances of this nanostructures from near infrared to the visible range may be tuned by adjusting the oxide size, size of the metal particles and the filling factor. For a better control of the optical properties of such composite materials the best choice as oxide material is the monodisperse oxide particles. Water-soluble metal precursor complexes hydrogentetrachloroaurate and silver acetate have been employed. The optical properties of these materials correspond to their overall structure of nanoparticulate composites having a very low filling factor of the metal phase.

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“…This can either cause the association or dissociation of protons to/from the oxide surface leading to positive or negative surface charge, respectively (Equations 1a and b) (19,20).…”

Section: Page 8 Of 17mentioning

confidence: 99%

Deposition of fluorescent NIPAM-based nanoparticles on solid surfaces: Quantitative analysis and the factors affecting it

Mohsen

Thorne

Alexander

et al. 2014

Colloids and Surfaces A: Physicochemical and Engineering Aspect

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This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Abstract Recently, responsive surfaces have attracted attention due to their potential applications. Reported research have studied the deposition of environmentally responsive particles on different surfaces, qualitatively tested their response to environmental conditions and studied their possible applications. In this work, novel fluorescent temperature-sensitive nanoparticles were synthesized using a surfactant free emulsion polymerization technique: poly(N-isopropylacrylamide-co-5% vinyl cinnamate) (p(NIPAM)5%VC). The new particles were characterized using dynamic light scattering and fluorescence spectroscopy. A novel sensitive method for the quantitative analysis of p(NIPAM) 5% VC using fluorescence spectroscopy was developed to determine the concentration of nanoparticle dispersions. This was further used to quantitatively determine the mass of nanoparticles deposited per unit area of glass pre-treated with acid, glass pre-treated with base, quartz, stainless steel, gold and teflon at 25°C and 60°C. Factors affecting the adsorption/desorption of the nanoparticles were studied, including the effect of substrate surface charge, surface roughness (using atomic force microscopy, AFM), hydrophilicity/hydrophobicity and the temperature at which the adsorption/desorption experiments were carried out. The results show that the effect of surface charge is the most significant, followed by that of surface roughness and temperature. Meanwhile, the influence of the hydrophobicity/hydrophilicity of the surface on the adsorption/desorption of nanoparticles appears to be far less significant than the previously mentioned factors.Keywords: fluorescent p(NIPAM), vinyl cinnamate, quantitative particle deposition, surface charge and surface roughness.

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Surface chemistry of SiO2 and TiO2–SiO2 glasses as determined by titration of soot particles

Cited by 31 publications

References 11 publications

Simultaneous Nanoscale Surface Charge and Topographical Mapping

Simultaneous Nanoscale Surface Charge and Topographical Mapping

Formation and Characterization of Gold and Silver Nanoparticles on Silica Nanospheres

Deposition of fluorescent NIPAM-based nanoparticles on solid surfaces: Quantitative analysis and the factors affecting it

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