With the growing emphasis on energy-saving and green, low-carbon building concepts, transparent thermal insulation coatings, a new material that can be applied directly to glass surfaces and combines both light-collecting and energy-saving properties, are attracting widespread attention. An ideal transparent thermal insulation coating must maintain high visible light transmittance while effectively blocking near-infrared radiation from solar radiation, which accounts for over 50% of heat and is the primary source of indoor temperature rise. However, traditional materials often struggle to achieve both transparency and thermal insulation. Adding insulating fillers can easily cause light scattering, reducing light transmittance; pursuing high light transmittance compromises thermal insulation. Small particle silica sols, with their unique nanoscale effects and chemical properties, are a key component in achieving this conflicting balance. 1. Nanoscale: Breaking the Physical Limits of Li
