“…The fi rst known report of LbL was the alternate adsorption of micrometer-scale colloidal particles of opposite charges. [ 55 ] Nanoparticle-based LbL fi lms have since been shown to exhibit electrical conductivity, [95][96][97][98][99][100] super hydrophobicity, [101][102][103][104][105] water repellency, [ 106 ] UV absorption, [ 107,108 ] optical fi ltering, [ 109 ] fl ame resistance, [ 110,111 ] strength, [112][113][114][115] and gas barrier [ 50,57,[116][117][118][119][120][121][122] by way of carbon nanotubes, spherical nanoparticles (e.g., TiO 2 and SiO 2 ), or two-dimensional nano platelets (e.g., clay and graphene).…”