02105nas a2200181   4500008004100000022001400041245010500055210006900160260000800229300001600237490000600253520144600259100002801705700001801733700001601751700002701767856012901794       2018                        eng d  a2046-206900aPreparation of macroporous scaffolds with holes in pore walls and pressure driven flows through them0 aPreparation of macroporous scaffolds with holes in pore walls an  cJAN  a24731-247390 v83 a<p>Controlling the pore architecture in macroporous scaffolds has important implications for their use as reactor packings and as catalyst supports. We report the preparation of a macroporous structure, where the pore walls are perforated by holes. These materials are prepared by modification of the ice-templating protocol developed in our group. We freeze a dispersion of colloidal silica, polymer and cross-linker in a water/acetonitrile medium and allow crosslinking to proceed in the frozen state. The presence of a small fraction of acetonitrile (varying between 1.6% to 6.4%) results in the formation of holes in the pore walls. Increasing the acetonitrile concentration changes the pore size distribution, and produces smaller pores on average. This also results in an increasing fraction of the wall area being covered by small pores, of the order of a few microns in size. Perforation of the walls by pores does not change the overall porosity or modulus of the scaffolds. However, the introduction of pores leads to a drastic reduction in the pressure drop required to pump liquid through the scaffolds. The observed residence time distribution (RTD) in the scaffolds is represented by two plug flow reactors (PFRs) in parallel. The RTD results indicate that increasing the hole fraction in the pore walls results in increased channelling which explains the aforementioned decreased pressure drop during pressure driven flow.</p>1 aChatterjee, Soumyajyoti1 aPotdar, Aditi1 aKuhn, Simon1 aKumaraswamy, Guruswamy  uhttps://library.ncl.res.in/content/preparation-macroporous-scaffolds-holes-pore-walls-and-pressure-driven-flows-through-them