Surface hydroxylation and silane grafting on fumed and thermal silica

Dugas, Vincent; Chevalier, Yves

doi:10.1016/s0021-9797(03)00552-6

Cited by 129 publications

(102 citation statements)

References 38 publications

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“…30,31 SiOH concentration on the SiO 2 surface has been determined to be ∼(3-7) × 10 13 cm -2 in a number of studies. 32,33 This concentration is nevertheless electronically significant, as it exceeds or is comparative to the typical carrier concentration of 10 13 cm -2 found recently in single Bi 2 Te 3 NP devices with a top gate and Bi 2 Te 3 nanoribbon based field-effect transistor (FET). 13,15 Such substrate surface condition leads to n-doping to the Bi 2 Te 3 NPs with relatively large surface potential and broad distribution as shown in Figure 6(a), which presents a practical challenge for probing topological insulator surface states by transport measurements.…”

Section: Surface Potentials Of Bi 2 Te 3 Npsmentioning

confidence: 64%

Growth and surface potential characterization of Bi2Te3 nanoplates

Hao

Yang

et al. 2012

AIP Advances

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Topological insulator Bi2Te3 nanoplates with hexagonal, triangular and truncated triangular nanostructures have been fabricated with thickness of ∼10 nm by vacuum vapor phase deposition method. The possible formation mechanism of Bi2Te3 nanoplates with different nanostructures has been proposed. We have examined the surface potentials of Bi2Te3 nanoplates using Kelvin probe force microscopy. The surface potential of Bi2Te3 nanoplates is determined to be about 482 mV on the SiO2/Si substrate, 88 mV and -112 mV on the n-doped and p-doped Si (111) substrates, respectively. The surface potential information provides insight into understanding electronic properties of Bi2Te3 nanoplates, which may open a new door to the exploration of the topological insulators

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Section: Surface Potentials Of Bi 2 Te 3 Npsmentioning

confidence: 64%

Growth and surface potential characterization of Bi2Te3 nanoplates

Hao

Yang

et al. 2012

AIP Advances

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“…the recovery of the original silanol density, is enforced through treatment with hydrolyzing compounds like Piranha or boiling water. 36,38 In this way average densities varying by a factor of about 20, namely from E0.25 OH nm À2 (T E1000 1C) up to E4.6 OH nm À2 (fully hydroxylated, T r 180 1C) were obtained. 36 The presented results for on-time contributions are discussed in the context of the above mentioned charge trapping model for single quantum objects and are attributed to hole trapping at surface sites at which silanol groups bind to the surface of the QDs.…”

Section: Introductionmentioning

confidence: 99%

Photoinduced hole trapping in single semiconductor quantum dots at specific sites at silicon oxide interfaces

Krasselt

Schuster

Borczyskowski

2011

Phys. Chem. Chem. Phys.

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Blinking dynamics of CdSe/ZnS semiconductor quantum dots (QD) are characterized by (truncated) power law distributions exhibiting a wide dynamic range in probability densities and time scales both for off-and on-times. QDs were immobilized on silicon oxide surfaces with varying grades of hydroxylation and silanol group densities, respectively. While the off-time distributions remain unaffected by changing the surface properties of the silicon oxide, a deviation from the power law dependence is observed in the case of on-times. This deviation can be described by a superimposed single exponential function and depends critically on the local silanol group density. Furthermore, QDs in close proximity to silanol groups exhibit both high average photoluminescence intensities and large on-time fractions. The effect is attributed to an interaction between the QDs and the silanol groups which creates new or deepens already existing hole trap states within the ZnS shell. This interpretation is consistent with the trapping model introduced by Verberk et al. (R. Verberk, A. M. van Oijen and M. Orrit, Phys. Rev. B, 2002, 66, 233202).

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“…3,4 또한 실리카는 실란 커플링제에 의해 표면이 개질될 수 있으며, 실란 커플링제는 용매 내에서 가수분해반응과 축합반응이 일어나는 것으로 알려져 있다. 5 유기계 실란 커플링제는 유기와 무기의 특성을 모두 가진 구조로서 일 반식은 R n -Si-(OR') 3 로 나타낸다. OR'은 물에 의한 가수분 해반응으로 R n -Si-(OH) 3 구조를 형성하여, 무기재료 표면의 −OH 기와 탈수화 반응을 통해 공유 결합이 이루어진다.…”

Section: 서 론unclassified

Quantitative Analysis of Silanization Degree of Silica Nanoparticles Modified with Bis[3-(trimethoxysilyl)propyl]amine Coupling Agent

Jeon¹,

Kim²,

Ha³

2012

Polymer Korea

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In this study, we treated silica nanoparticles with bis[3-(trimethoxysilyl)propyl]amine (BTMA) silane coupling agent to modify their surfaces. We investigated the effects of BTMA hydrolysis time, BTMA concentration and BTMA treatment time on the degree of silanization reaction of silica nanoparticles. We used Fourier transform infrared spectroscopy (FTIR), elemental analysis (EA) and solid state cross-polarization magic angle spinning (CP/MAS) nuclear magnetic resonance spectroscopy (NMR) to obtain quantitative data. We found the decrease of isolated Si-OH peak intensity at 3747 cm −1 and the increase of −CH 2 stretching and bending peaks with increasing hydrolysis time, concentration and treatment time of BTMA. EA analysis results also supported this trend. We found a strong effect of BTMA concentration on the degree of silanization of the silica particles, but weak effects of the hydrolysis time and the treatment time.

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Surface hydroxylation and silane grafting on fumed and thermal silica

Cited by 129 publications

References 38 publications

Growth and surface potential characterization of Bi2Te3 nanoplates

Growth and surface potential characterization of Bi2Te3 nanoplates

Photoinduced hole trapping in single semiconductor quantum dots at specific sites at silicon oxide interfaces

Quantitative Analysis of Silanization Degree of Silica Nanoparticles Modified with Bis[3-(trimethoxysilyl)propyl]amine Coupling Agent

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