title: Experimental investigation of the band broadening originating from the top and bottom walls in micromachined nonporous pillar array columns.
abstract: We report on the experimental investigation of the effect of the top and bottom wall plates in micromachined nonporous pillar array columns. It has been found that their presence yields an additional c-term type of band broadening that can make up a significant fraction of the total band broadening (at least if considering nonporous pillars and a nonretained tracer). Their presence also induces a clear (downward) shift of the optimal velocity. These observations are, however in excellent quantitative agreement with the theoretical expectations obtained from a computational fluid dynamics study. The presently obtained experimental results, hence, demonstrate that the employed high aspect ratio Bosch etching process can be used to fabricate micromachined pillar arrays that are sufficiently refined to achieve the theoretical performance limit.
authors: Department of Chemical Engineering, Vrije Universiteit Brussel, Brussel, Belgium.
authors: Hamed
authors: H
authors: Eghbali
authors: Wim
authors: W
authors: De Malsche
authors: Jan
authors: J
authors: De Smet
authors: Jeroen
authors: J
authors: Billen
authors: Mauro
authors: M
authors: De Pra
authors: Wim Th
authors: WT
authors: Kok
authors: Peter J
authors: PJ
authors: Schoenmakers
authors: Han
authors: H
authors: Gardeniers
authors: Gert
authors: G
authors: Desmet