Fabrication of mechanically robust antireflective films using silica nanoparticles with enhanced surface hydroxyl groups

Wang, Y.; He, Mengyao; Chen, R. Y.

doi:10.1039/c4ta04840g

Cited by 34 publications

(28 citation statements)

References 37 publications

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“…Although the link between hydroxyl coverage and surface adsorption has long been established, 11 there is still a need to understand silicawater interactions and their technological and biological implications at the molecular scale and nanoscale. It has been shown, for example, that the proportion of hydroxyls on small silica particles can be deliberately increased by physico-chemical processing to produce enhanced properties for applications (e.g., mechanically robust antireflective films 12 and epoxidation catalysis 13 ). For particularly well-defined silica nanoslabs, even the spatial distribution of hydroxyls can be tuned experimentally with potential for templating supported species.…”

Section: Introductionmentioning

confidence: 99%

“…[23][24][25][26] For considerably larger hydroxylated nanosilica systems, typically involving thousands of atoms, classical force field methods have also been applied. 12,27,28 Although numerous force fields have been proposed in the literature for modeling such large nanosilicawater systems and/or bulk silica surfaces interacting with water, 19,[29][30][31][32][33][34][35][36][37] very few force fields have been tested to some degree with respect to their adequacy for treating hydroxylated nanosilica systems possessing of the order of 100 atoms. 19,38 The size regime for systems possessing between 10s and 100s of atoms is particularly important as it addresses the transition between molecular and bulk scales.…”

Section: Introductionmentioning

confidence: 99%

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Modeling hydroxylated nanosilica: Testing the performance of ReaxFF and FFSiOH force fields

Escatllar

Ugliengo

Bromley

2017

The Journal of Chemical Physics

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We analyze the performance of the FFSiOH force field and two parameterisations of the ReaxFF force field for modeling hydroxylated nanoscale silica (SiO). Such nanosystems are fundamental in numerous aspects of geochemistry and astrochemistry and also play a key role during the hydrothermal synthesis of technologically important nanoporous silicas (e.g., catalysts, absorbents, and coatings). We consider four aspects: structure, relative energies, vibrational spectra, and hydroxylation energies, and compare the results with those from density functional calculations employing a newly defined dataset (HND: Hydroxylated Nanosilica Dataset). The HND consists of three sets of (SiO)(HO) nanoparticles (NPs), each with a different degree of hydroxylation and each containing between 23 and 26 distinct isomers and conformers. We also make all HND reference data openly available. We further consider hydroxylated silica NPs of composition (SiO)(HO) with M = 4, 8, 16, and 24 and infinite surface slabs of amorphous silica, both with variable hydroxylation. For energetics, both ReaxFF and FFSiOH perform well for NPs with an intermediate degree of hydroxylation. For increased hydroxylation, the performance of FFSiOH begins to significantly decline. Conversely, for the lower degree of hydroxylation both parameterisations of ReaxFF do not perform well. For vibrational frequencies, FFSiOH performs particularly well and significantly better than ReaxFF. This feature also opens the door to inexpensively calculating Gibbs free energies of the hydroxylated nanosilica systems in order to efficiently correct density functional theory calculated electronic energies. We also show how some small changes to FFSiOH could improve its performance for higher degrees of hydroxylation.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Modeling hydroxylated nanosilica: Testing the performance of ReaxFF and FFSiOH force fields

Escatllar

Ugliengo

Bromley

2017

The Journal of Chemical Physics

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“…Examination of Figure 4(d) also reveals the growth of a broad band at ∼3425 cm −1 which has been previously assigned to the hydroxyl (O-H) group [36,37]. A plot of the Si-H peak position as a function of time for the T D = 150°C film is shown in Figure 5, including a Gaussian fit (inset) suggesting that this absorption band arises primarily from Si-H vibration with a small contribution from Si-H 2 [38,39].…”

Section: Xps and Ftir Analysismentioning

confidence: 52%

Effect of oxidation on intrinsic residual stress in amorphous silicon carbide films

et al. 2018

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The change in residual stress in PECVD amorphous silicon carbide (a-SiC:H) films exposed to air and wet ambient environments is investigated. A close relationship between stress change and deposition condition is identified from mechanical and chemical characterization of a-SiC:H films. Evidence of amorphous silicon carbide films reacting with oxygen and water vapor in the ambient environment are presented. The effect of deposition parameters on oxidation and stress variation in a-SiC:H film is studied. It is found that the films deposited at low temperature or power are susceptible to oxidation and undergo a notable increase in compressive stress over time. Furthermore, the films deposited at sufficiently high temperature (≥ 325 °C) and power density (≥ 0.2 Wcm −2 ) do not exhibit pronounced oxidation or temporal stress variation. These results serve as the basis for developing amorphous silicon carbide based dielectric encapsulation for implantable medical devices.

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“…After identifying that the mesoporous silica-loaded perfluorooctylethanol can improve the triboelectric output of TENG, we also studied the antiwear and friction-reducing effects of TENG, which was very important for its practical applications. − Figure reports the friction coefficients and wear volume of the pure acrylate coating and the coating loaded with 2% mesoporous SiO 2 nanoparticle and F-SiO 2 additives. As shown in Figure a, for the pure acrylate, the friction coefficient rapidly increased from a small value to approximately 0.11 and remained within this range.…”

Section: Resultsmentioning

confidence: 99%

New Coating TENG with Antiwear and Healing Functions for Energy Harvesting

Kong

Liu

et al. 2020

ACS Appl. Mater. Interfaces

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In view of the limitations of practical applications of current triboelectric nanogenerators (TENGs), a new type of coating TENGs with antiwear and healing properties have been fabricated to collect the large-scale dissipative energy in the environment. To enhance the triboelectrification performance of the coating TENG, mesoporous silica filled with perfluorooctylethanol is added to the acrylate resin material, in addition to improving the antiwear properties of the frictional coating. The result shows that when the mesoporous silica is used as a carrier and perfluorooctylethanol is loaded, the short-circuit current (I sc ) and output voltage (V o ) of the coating TENG reach as high as 10 μA and 220 V, respectively, which are 4−5 times higher than those of pure acrylate. More importantly, the coefficient of friction of the new coating decreases from 0.11 to 0.04 with the wear volume reducing by approximately 89%, indicating a better friction-reducing property of the coating for long-term working. As a new coating material based on the traditional acrylic resin, it can be widely sprayed onto various walls, metals, and hulls as protection coating as well as power-generation coating. Interestingly, when the coating is damaged due to long-term aging or external mechanical forces, it can restore its triboelectric performance by encapsulating the repair agent within the pore structure of silica. Owing to the large-area fabrication, low cost, high output performance, and antiwear properties, the new coating TENGs have promising potential for practical applications in energy-harvesting, self-energy supplies, and self-powered sensors.

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Fabrication of mechanically robust antireflective films using silica nanoparticles with enhanced surface hydroxyl groups

Abstract: H2O2 modification enables greater interaction between the silica nanoparticles and the linear silicate polymers, thereby increasing mechanical properties and AR durability of the composite films.

Cited by 34 publications

References 37 publications

Modeling hydroxylated nanosilica: Testing the performance of ReaxFF and FFSiOH force fields

Modeling hydroxylated nanosilica: Testing the performance of ReaxFF and FFSiOH force fields

Effect of oxidation on intrinsic residual stress in amorphous silicon carbide films

New Coating TENG with Antiwear and Healing Functions for Energy Harvesting

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