Fillingis

Fillingis is a term used in materials science and engineering to describe a class of processes and materials that seal or occupy void spaces within porous or fibrous structures to modify their physical properties. The concept encompasses a range of injectable, in situ-curing, or in situ-formed fillers that aim to reduce porosity, tailor interfacial characteristics, and improve performance of composites, membranes, and energy storage devices.

Fillers may be polymeric resins, ceramic particles, metal powders, or phase-changing materials selected for chemical compatibility with the host structure. The filling can occur by capillary impregnation, injection under pressure, or chemical in situ polymerization. Desired outcomes include reduced permeability, enhanced thermal conductivity, increased stiffness, or improved dielectric properties, depending on filler type and loading.

Applications span energy storage, where filled porous electrodes or separators reduce resistance and swelling; filtration and separation, where pore filling improves selectivity; and structural components, where filled porosities increase stiffness and damage tolerance.

The term fillingis is not part of a standard taxonomy; it emerged in a small body of contemporary literature and remains variably defined across disciplines. It is often discussed alongside related concepts such as impregnation, infiltration, and pore filling.

Challenges include achieving uniform distribution of filler, maintaining connectivity of pores for transport, processing at practical temperatures and viscosities, and cost considerations. Long-term stability and potential degradation at service conditions are active areas of research.