R. Netrabukkana et al., DIFFUSION OF GLUCOSE AND GLUCITOL IN MICROPOROUS AND MESOPOROUS SILICATE ALUMINOSILICATE CATALYSTS, Industrial & engineering chemistry research, 35(2), 1996, pp. 458-464
The effective diffusivities of glucose and its linear analog glucitol
were measured by a liquid chromatographic technique at 30 degrees C wi
thin water-filled silica and aluminosilicate catalysts of mean pore si
ze ranging from 7.4 to 116 Angstrom. For glucose, the effective diffus
ivity decreased from 1.08 x 10(-6) to 1.77 x 10(-9) cm(2)/s as the mea
n pore size decreased from 116 to 7.4 Angstrom. All values were signif
icantly lower than the molecular diffusivity of 7.02 x 10(-6) cm(2)/s.
The effective diffusivities for glucitol were three times lower than
those for glucose over the same pore size range due to differences in
solute size, structure, and solute-adsorbent interactions. The 8.6 Ang
strom glucose molecule-was able to diffuse into the 7.4 Angstrom Y-zeo
lite pore, possibly as its acyclic form. However, the 9.7 Angstrom glu
citol molecule could not diffuse into the Y-zeolite pore. The reduced
diffusivity was correlated to the reduced pore diameter using the Tern
an model.