Diffusion of dissolved ions from wet silica sol-gel monoliths: Implications for biological encapsulation

► Explored diffusion in wet silica gels relevant to biological encapsulation. ► Used a variety of tracers and gel compositions. ► Tracer size, not gel hydrophobicity, is the primary determinant of diffusion. ► Gels can be tailored to the bio-component without significantly altering diffusion. ► Diffusion adequate to support viable photoautotrophic organisms.