Diffusion and optical properties of Nd-doped sol-gel silica glasses

Diffusion of solvents and cations in porous sol-gel glass

“…This is contrary to the results obtained for Nd 3+ [2]. At this time we do not have a mechanism to explain this behavior.…”

“…They were obtained by fitting experimental results with Eq. (2). An example of a fit for Er a+ inside 4.2 nm pore diameter sol-gel glass after 48 hours exposure to aqueous erbium chloride is shown in One must consider the coordination sphere of rare earth cations in order to interpret the diffusion coefficients of Er a+ and Nd 3+.…”

“…This method of manufacture produces lenses of optical quality but limited in size, less than 3 mm in diameter. An alternative process for making GRIN lenses could be accomplished by diffusing liquids containing cations into previously manufactured, stabilized porous sol-gel monoliths [2]. The process is similar to the "molecular stuffing" process described by Asahara et al [3].…”

Sonochemical Processes and Formation of Gold Nanoparticles within Pores of Mesoporous Silica

“…A series of the preformed monolithic mesoporous silica host (parallel samples) was immersed in a 0.8 mmol L −1 HAuCl 4 solution (containing 0.2 mol L −1 isopropanol) for 3 weeks, which is long enough to make the concentrations of AuCl − 4 ions and isopropanol in the pores of the mesoporous silica be the same as those in bulk solution (21). After sufficient immersion, the solid samples with the corresponding mixed solution (about 50 ml) were transferred to the conical flask with cover, which was put in the sonication bath.…”

Diffusion of steroids in porous sol-gel glass: Application in slow drug delivery

“…In our previous publications we studied translational and rotational diffusion of simple liquids inside the pores such as chloroform, pyridine, acetone, acetonitrile, carbon disulfide, toluene, water, cyclohexane [2][3][4][5][6]. More recently, the flow of metal cations into the porous sample to form a gradient index glass has also been investigated [7]. In this paper we study a reversed problem, the flow of steroid molecules out of the sample.…”