Porous structure such as for filters, and making the same

A method of making a porous structure configured for use in a particulate filter, comprising:

• bonding a plurality of glass bubbles to one another, wherein the glass bubbles have a D50 particle size of at least 1 micrometer but no more than 100 micrometers, wherein the plurality comprises at least 1000 of the glass bubbles;
• heating the plurality of glass bubbles to at least a softening temperature of the glass bubbles;
• and
• breaching the glass bubbles, wherein the breaching occurs concurrently with the heating;
• wherein, in aggregate, the bonded, breached glass bubbles form the porous structure, and wherein voids within individual breached glass bubbles open into one another to form cavities that extend through the porous structure and to surfaces thereof.