Development of colored surfaces by formation of nano-structured aggregates is a widely used strategy in nature to color lightweight structures (e.g. butterflies) without the use of dye pigments. The deposition of nanoscale particles mimics nature in it’s approach coloring surfaces. This work presents sol-gel modification of cellulose surfaces used to form a template for growth of Cu/Cu₂O core-shell particles with defined size-distributions. Besides improving the adhesion of the deposited particulate material, the sol-gel matrix serves as a template for the control of particle sizes of the Cu/Cu₂O structures, and as a consequence of particle size variation the surface color is tunable. As an example, red color was achieved with an average particle size of 35 nm, and shifts gradually to blue appearance when particles have grown to 80 nm on the sol-gel modified fabric. The copper concentration on representative fabrics is kept low to avoid modifying the textile characteristics and were all in the range of 150–170 mg per g of cellulose material. As a result of copper deposition on the surface of the material, the cellulose fabric also became electrically conductive. Remarkably, the electrical conductivity was found to be dependent on the average particle sizes of the deposits and thus related to the change in observed color. The generation of color by growth of nano-sized particles on sol-gel templates provides a highly promising approach to stain surfaces by physical effects without use of synthetic colorants, which opens a new strategy to improve environmental profile of coloration.

通过形成纳米结构的聚集体来形成有色表面是自然界广泛使用的策略，用于在不使用染料的情况下为轻质结构（例如蝴蝶）着色。纳米级颗粒的沉积在接近着色表面时模仿了自然。这项工作提出了纤维素表面的溶胶-凝胶改性，用于形成具有确定的尺寸分布的生长Cu / Cu ₂ O核壳颗粒的模板。溶胶-凝胶基质除了改善沉积颗粒材料的附着力外，还充当控制Cu / Cu ₂粒径的模板O型结构，并且由于粒径变化，表面颜色是可调的。例如，红色的平均粒径为35 nm，当溶胶-凝胶改性的织物上的颗粒长至80 nm时，颜色逐渐变为蓝色。代表织物上的铜浓度应保持在较低水平，以避免改变纺织品的特性，且每克纤维素材料的铜浓度均在150-170 mg之间。由于铜沉积在材料表面上，纤维素织物也变得导电。值得注意的是，发现电导率取决于沉积物的平均粒径，因此与观察到的颜色变化有关。