A study of water diffusion, in both radial and axial directions, into biodegradable monolithic depots using ion beam analysis

Effective diffusion coefficient determination within cylindrical granules of adsorbents using a direct simulation method

“…Values were determined from individual time and adsorption points. The effective diffusion coefficient of water in a polymeric cylinder was determined by fitting radial diffusion curves to experimental data [13]. However, analytical expressions to Fick's Second Law involve infinite series.…”

In situ water permeation measurement using an external 3He2+ ion beam

“…The energy loss of 3 He 2+ beams in air is much greater than for proton beams, and allows experimenters the possibility of rapid changes in incident beam energy on the sample, simply by altering the size of the air gap between the beam exit nozzle and the sample surface [10]. The D( 3 He,p)␣ reaction has been widely exploited to measure water ingress into solid samples [12][13][14][15][16], and has normally been applied under vacuum to vitrified samples. This technique is also well-established in polymer science [17][18][19] to detect the diffusion [20] and adsorption [21] of deuterated polymers.…”