Amorphous silica

Aerocelluloses are considered as “third generation” aerogels after the silica and synthetic polymer-based ones. However, their brittleness and low optical translucency keep quite narrow their fields of applications.

7p vihermione 06-01-2023 4 2   Download

A new method is outlined for constructing realistic models of the mesoporous amorphous silica adsorbent, MCM-41. The procedure uses the melt-quench molecular dynamics technique. Previous methods are either computationally expensive or overly simplified, missing key details necessary for agreement with experimental data.

9p vironald 15-12-2022 5 2   Download

In the quest to increase the quality of life and life expectancy, there is a great demand to develop advanced medical devices capable of facing current health challenges. Santa Barbara Amorphous (SBA-15) mesoporous silica has been demonstrated to be a remarkable option for a variety of biomedical applications, from tissue engineering to drug delivery, due to its unique hierarchical porous structure.

12p vironald 15-12-2022 4 2   Download

The molecular dynamic simulation has been conducted to study the behavior of void and void clusters in liquid silica under temperature. We focused on two kinds of void aggregation: void cluster and void tube. The evolution of structural changes of silica under temperature has been analyzed through coordination number, angle distribution and void characteristics. It was found that there is a large void tube composed of 91% O-void spread over simulation shell. The temperature dependence of different kinds of void seems to be very week in comparison with pressure.

5p thienlangso 15-12-2021 11 0   Download

The present paper aimed at the investigation of the effect of preliminary acid treatment on the structure and purity of extracted silica. In this study, the acid leaching of rice husk (RH) in 2 M hydrochloric acid solution before the calcination process at 600◦C was proposed to achieve completely white silica with high specific surface area and low content of impurities. RH, selected from the Almaty Region, Kyzylorda Region, and Turkestan Region was used as the main silica source. The results confirmed that the highest purity (98.2%–99.

12p tudichquannguyet 29-11-2021 8 1   Download

The change of short and intermediate range orders in a model of amorphous silica at 500 K in the 0-100 GPa pressure range is investigated using molecular dynamics simulation. The pressure dependence of the bond length, bond angle and coordination distribution is analysed in detail.

6p tamynhan9 02-12-2020 6 2   Download

In this work, we use molecular dynamic (MD) simulation to study the structure transition and crystallization of amorphous silica (SiO2) under compression. The structural evolution of amorphous SiO2 is explained through radial distribution function, coordination number distribution, bond angle distribution and visualization.

10p tamynhan6 14-09-2020 10 2   Download

To improve the solubility and oral bioavailability of erlotinib, a poorly water-soluble anticancer drug, solid self-emulsifying drug delivery system (SEDDS) was developed using solid inert carriers such as dextran 40 and Aerosil® 200 (colloidal silica). The preliminary solubility of erlotinib in various oils, surfactants, and co-surfactants was determined. Labrafil M2125CS, Labrasol, and Transcutol HP were chosen as the oil, surfactant, and co-surfactant, respectively, for preparation of the SEDDS formulations. The ternary phase diagram was evaluated to show the self-emulsifying area.

8p caothientrangnguyen 09-05-2020 13 1   Download

In this study, Wood Ash (WA) prepared from the uncontrolled burning of the saw dust is evaluated for its suitability as partial cement replacement in conventional concrete. The saw dust has been acquired from a wood polishing unit. The physical, chemical and mineralogical characteristics of WA is presented and analyzed. The strength parameters (compressive strength, split tensile strength and flexural strength) of concrete with blended WA cement are evaluated and studied. Two different water-to-binder ratio (0.4 and 0.

7p trinhthamhodang1 16-11-2019 14 1   Download

The X-ray diffraction (XRD) pattern with only one peak at 2θ ~ 220 confirmed the amorphous phase of SiO2 NPs. The Fourier transform infrared (FTIR) and energydispersive X-ray (EDX) spectra were also used to evaluate the functional groups and the purity of SiO2 NPs. The SiO2 NPs powder with high purity could be suitably produced by calcination of acid treated RHA at 7000 C for 2h.

5p everydaywish 25-12-2018 28 0   Download

The characterization results show that the obtained amorphous silica was 99.8 % purity with average particle size of 5–10 nm, and high specific surface area of 224 m2 /g. Additionally, for the first time that RHA–silica was successfully applied as an anti–caking agent for a NPK–fertilizer. A suitable content of silica was evaluated through the level of anti–caking. The testing results show that with only 1.5 wt% of RHA–silica particles could replace kaolin as an anti–caking agent for the NPK–fertilizer.

9p cumeo3000 01-08-2018 30 1   Download

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Effect of amorphous silica nanoparticles on in vitro RANKL-induced osteoclast differentiation in murine macrophages

5p sting04 07-02-2012 38 5   Download