Understanding the effects of lighting upon the appearance of fabrics.

目前的洗衣配方使用光学增白剂，以使洗涤的织物呈现出更明亮、更平衡的白色。它们的工作原理是吸收来自人造照明的阳光中的紫外线，并通过光谱蓝色部分的荧光重新发射这些吸收的能量，以抵消发黄或“昏暗”的织物。另一种产生这种效果的方法是在衣物中添加“染色剂”，比如“利洁时蓝袋”。这种较老的技术（19世纪中期）通过吸收光谱中的红色和绿色部分的光来影响织物的感知颜色，恢复物体的白色平衡，但使其不那么明亮。现代照明技术正从产生紫外线的荧光灯转向使用白光LED技术。这些新光源不产生紫外线辐射，因此除非在室内，否则将提供光学增白剂。这项工作将研究织物的基本吸收、发射和散射特性，以及在不同照明条件下可用于改变其外观的药剂，以期在各种照明条件下改善洗涤后衣物的感知颜色。

Currently laundry formulations employ optical brighteners in order to make the fabrics washed in them appear a brighter and better balanced white. These work by absorbing UV light from either sunlight for artificial lighting, and re-emitting this absorbed energy by fluorescence in the blue portion of the spectrum, countering the yellowing or 'dingy' fabrics. An alternative way of bringing about this effect is to add a 'hueing dye' to the laundry, such as 'Reckitts Blue Bags. This older technology (mid 19th century) affects the perceived colour of a fabric by absorbing light in the red and green portions of the spectrum, restoring the white colour balance to the object, but making it less bright. Modern lighting technology is tending away from UV-generating fluorescent lighting, and towards the use of white LED technologies. These new light sources produce no UV radiation and hence will render the optical brighteners unless indoors. This work will examine the fundamental absoroption, emission and scattering properties of fabrics and the agents that may be used to change their appearance under various lighting scenarios, with a view to improving the perceived colour of laundered clothing under a variety of lighting conditions.