In this paper, we demonstrate the fabrication of conductive porous polymers based on foaming of an aqueous dispersion of polymeric particles and multi-walled carbon nanotubes (CNT). By tuning the surface energy of the constituents, we direct their preferential adsorption at the air-liquid (bubble) interface or within the liquid film between the bubbles. Sintering this bi-constituent foam yields solid closed-cell porous structure which can be electrically conductive if CNT are able to form a conductive path. We measure transport (electrical and thermal), mechanical, and morphological properties of such porous structures as a function of CNT loading and the method used for their surface functionalization. For a fixed polymer volume fraction, we demonstrate the limit in which increasing CNT results in decreasing the mechanical strength of the sample due to lack of adequate polymer-CNT bond. Such lightweight conductive porous composites are considered in applications including EMI shielding, electrostatic discharge protection, and electrets.Porous polymer foams are conventionally produced using chemical/physical blowing agents or templating using droplets (emulsion) or solid particles (porogen) 1, 2 . Major limitations of these techniques include lack of control over pore size/size distribution, and applicability to only melt/solution-processable polymers [3][4][5][6] . High viscosity of polymer melts also proves to be challenging for uniform distribution of nanofillers in order to fabricate functional materials. Intractable polymers (i.e. those possessing a high glass transition temperature combined with a relatively low degradation temperature or those having a high molecular weight) cannot be easily melt-processed due to their high melt viscosity. However, such polymers are being used in many practical applications. For instance, Poly(ether ether ketone) (PEEK) is employed for its erosion resistance and excellent mechanical properties at elevated temperatures in pump and valve components as well as in transformer housings, battery holders, and fuel-line brackets. Poly(tetrafluoroethylene) (PTFE) is another example of an intractable polymer known for its non-reactivity and low friction properties in automotive industry. To fabricate porous materials from such polymers, different processes have been developed. They include dispersing of intractable polymer particles in thermally-stable matrices, sintering of uncompressed polymer powders, and inclusion of hollow microspheres typically made of glass, metal, and ceramics inside polymer matrices, i.e. syntactic foams [7][8][9] . However, these processes generally lead to low porosity (<40% air content) which may not be adequate for some applications 10,11 .An alternative approach to fabricate porous structures is to utilize particle-stabilized aqueous foams as precursor 11 . The process is based on the fact that fine solid particles can stabilize liquid-air interfaces resulting in foams that resist bubble coalescence and coarsening. Both melt-processable and intractabl...