Described herein are insulating structures that include at least one microporous layer including a plurality of pores, a porous layer adjacent to the microporous layer, and a monolithic aerogel structure extending through the plurality of pores of the microporous layer and through at least part of the porous layer. The microporous layer filters aerogel dust from cracked or damaged aerogel within the scaffold, slowing or preventing loss of dust from the insulating structures.