The preparation of gold nanoparticle composites using supercritical carbon dioxide

A new gas/supercritical fluid (SCF) diffusivity measurement method for CO2 saturated polymer systems using a dielectric property

“…The expression for an analytical solution is (Equation (4)): (4) where M max is the total amount of a diffusing substance absorbed by the polymer sheet at the onset of desorption, M t is the corresponding quantity of the gas at time t and L is the film thickness. Based on Equation (4), two different diffusion coefficients corresponding to different periods of the diffusion process are given as D short and D long .…”

“…Gas permeability is observed to decrease with increasing dielectric constants of the membrane films during steady diffusion. Miyata's research team studied the gas transport properties and dielectric properties of four hexafluoroisopropylidene polyimides with CO 2 , CH 4 , H 2 , O 2 and N 2 [12]. They also tested the gas permeability at a steady state condition and claimed that gas permeability coefficients were higher with films with lower dielectric constants as shown by Matsumoto et al's study [14].…”

“…Several groups investigated the relationship between a gas transport property and dielectric constants for various polymer and gas combinations at steady state conditions for membrane filter applications [14,15]. Matsumoto et al [14] reported the relationship between CO 2 , CH 4 , H 2 , O 2 , N 2 gas permeability and dielectric constant values of several aromatic polyimides films. Gas permeability is observed to decrease with increasing dielectric constants of the membrane films during steady diffusion.…”

Synthesis of superhydrophobic polymer/tungsten (VI) oxide nanocomposite thin films

“…Other previous, well-established methods for achieving nanoparticle incorporation into a polymer film include supercritical fluid deposition (SFD), in which nanoparticles are synthesised in-situ by a wet chemical reduction of a metal salt within the polymer matrix [7], and the 'casting' method, in which the matrix is polymerised around the nanoparticles [8]. However, both inherently require synthesis of one component within or around the other, which naturally affords limited control over polymer dispersity and morphology, and nanoparticle size and/or crystal phase.…”

Preparation of Platinum/Montmorillonite Nanocomposites in Supercritical Methanol and Their Application in the Hydrogenation of Nitrobenzene

“…As mentioned above, there are many methods in the incorporation of metal precursors into a substrate, e.g., montmorillonite, among which the supercritical fluids (SCFs) aided method is a newly developed, effective route in the preparation of nanocomposites [11][12][13][14][15] based on the unique properties of supercritical fluids, including low viscosity, high diffusivity, near zero surface tension and tunable solubility, and a variety of noble metal nanoparticles including Au, Pd, Ru, Rh, Pt have been deposited on various supports, such as polymer, inorganic mesoporous materials, and carbon nanotubes in supercritical CO 2 [16][17][18][19][20][21][22], supercritical water [23], and supercritical methanol solution [24].…”