Nanofiller

Nanofiller is a term used for nanoscale particles that are added to a host material, often a polymer, to enhance its properties. Nanofillers have at least one dimension in the 1 to 100 nanometer range, which provides a high surface area and strong interfacial effects that influence the performance of the composite. They are employed to improve mechanical properties such as strength and stiffness, thermal stability and heat resistance, barrier properties to gases and liquids, wear resistance, flame retardancy, and, in some cases, electrical or thermal conductivity.

Common nanofillers include inorganic types such as silica, alumina, and titania nanoparticles; layered silicates (nanoclays) that can be exfoliated or intercalated; and carbon-based fillers such as carbon nanotubes and graphene or graphene oxide. Organic nanofillers like nanocellulose or polymeric nanoparticles are also used in specific applications.

Preparation and dispersion are critical. Nanofillers are introduced by melt compounding, solution blending, or in situ polymerization, often aided by surface modification with silanes, polymers, or surfactants to improve compatibility and prevent agglomeration.

Characterization methods focus on dispersion quality and interfacial interactions, using electron microscopy (TEM/SEM), X-ray diffraction to assess exfoliation or intercalation, and thermal or mechanical analysis (DSC, DMA, TGA) to quantify property changes. Rheological measurements help evaluate processability.

Applications span automotive and aerospace lightweight components, food and pharmaceutical packaging with improved barriers, protective coatings and paints, electronic and energy storage devices, and dental or biomedical composites.

Challenges include achieving uniform dispersion at higher loadings, balancing property gains with processability, cost considerations, and safety concerns related to inhalation or exposure during handling.