One-Dimension Diffusion Preparation of Concentration-Gradient Fe2O3/SiO2 Aerogel

Abstract

Concentration-gradient Fe2O3/SiO2 aerogels were prepared by placing an MTMS (methyltrimethoxysilane)-derived SiO2 aerogel on an iron gauze with an HCl atmosphere via one-dimensional diffusion, ammonia-atmosphere fixing, supercritical fluid drying and thermal treatment. The energy dispersive spectra show that the Fe/Si molar ratios change gradually from 2.14% to 18.48% with a height of 40 mm. Pore-size distribution results show that the average pore size of the sample decreases from 15.8 nm to 3.1 nm after diffusion. This corresponds well with TEM results, indicating a pore-filling effect of the Fe compound. In order to precisely control the gradient, diffusion kinetics are further studied by analyzing the influence of time and position on the concentration of the wet gel. At last, it is found that the diffusion process could be fitted well with the one-dimensional model of Fick’s second law, demonstrating the feasibility of the precise design and control of the concentration gradient.

Preparation, Characterization, and In Vitro Evaluation of Resveratrol-Loaded Cellulose Aerogel

“…For a long time, as a representative of inorganic aerogels, silica aerogels have been widely studied and applied because of their low cost and good structure and properties [7,8]. In the field of biomedicine, previous studies have shown the diffusion mechanism of drugs in silica aerogels [9,10], and that silica nanoparticle-loaded drugs have had good targeted therapeutic effects on diseases [11,12]. In recent years, considering the degradability of materials, scientists have turned their attention to the development of natural polymers [13].…”

“…However, cellulose aerogel was also a promising carrier material for drugs, enzymes, and proteins [21]. It can play a role in controlling release [22] and targeted transportation [10]. In addition, the stability of the drug can also be improved [23].…”

SILVER SULFATE (Ag2SO4): MOLECULAR ANALYSIS AND ION TRANSPORT

“…Hukum Fick (96)(97)(98)(99)(100)(101) Persamaan ini tertata ulang menjadi hasil yang sangat penting, yang dikenal sebagai hubungan Einstein, antara oefisien difusi dengan mobilitas ion (88)(89)(90)(91) .…”

“…elektron (56)(57)(58)(59)(60)(61)(62)(63)(64) yang digunakan untuk membentuk ikatan kovalen polar (65)(66)(67)(68)(69)(70)(71)(72)(73) lebih kuat tertarik pada salah satu atom. Parameter transfer ion (74)(75)(76)(77)(78) disini yaitu kecepatan hanyut (79)(80)(81)(82) , bilangan transport (83)(84)(85)(86)(87) , mobilitas ion (88)(89)(90)(91) , difusi (92)(93)(94)(95) , dan hukum I Fick (96)(97)(98)(99)(100)(101) dari senyawa perak sulfat (Ag2SO4).…”

Electrochemical Performance of Iron Oxide Nanoflakes on Carbon Cloth under an External Magnetic Field

“…In order to get higher energy density several strategies have been explored to design and fabricate electrode materials with various porous and hierarchical nanostructures, which are conducive to enhance specific capacitances and modify the rate performances [4][5][6][7][8]. Iron oxides (such as Fe 2 O 3 and Fe 3 O 4 ) have been brought into focus as electrode candidates for supercapacitors in a variety of materials [9][10][11][12]. Specifically, α-Fe 2 O 3 materials have been synthesized and reported elsewhere because of their high theoretical capacitance, low cost, and abundant chemical valences.…”