Lateral size modulated structural color of aqueous dispersions of titanate nanosheets

Deionized suspensions of titanate nanosheets exhibit vivid structural colors arising from the formation of lamellar liquid-crystalline phases. We investigated the impact of lateral size on the resulting structural coloration. A decrease in average lateral size (aspect ratio) shifts the structural color toward a blue dominant tone and narrows the reflection bandwidth, indicating an improvement in structural regularity. This behavior can be attributed to the faster orientational relaxation of smaller nanosheets, which may promote better alignment to enhance color purity. The current study establishes lateral-size modulation as a practical and broadly applicable strategy for achieving higher color purity in colloidal structural color systems.