Summary: A new kind of very fine disperse porous bead cellulose is modified by chemical treatments to 2,3-dialdehyde cellulose, carboxymethyl and dihydrogenphosphate cellulose. Model drugs like benzocaine and prazosin are coupled to these modified bead celluloses by covalent and ionic linkage, respectively and compressed to tablets. Compression mixtures with low loaded benzocaine conjugates release with medium rate. Linkage of prazosin cation to the anionic derivatives of bead cellulose leads to fast release of poor soluble ionic drug.

Radiative cooling, which normally requires relatively high infrared (IR) emissivity, is one of the insects’ effective thermoregulatory strategies to maintain their appropriate body temperature. Recently, the physical correlation between the delicate biological microstructures and IR emissivity for thermal radiation draws increased attention. Here, a scent patch region on the hindwing of Rapala dioetas butterfly is found to exhibit enhanced IR emissivity compared with the non-scent patch regions. A series of optical simulations are conducted to differentiate the effect of biological structures and material composition on the high IR emissivity. Besides the intrinsic IR absorption (emission) of chitin (the main composition of butterfly wings), the hierarchical microstructures of the scent patch scale further improve the IR absorption (emission) through the increased inner surface area and multi-scattering effect. This enhancement of IR emissivity enables the butterfly to efficiently radiate heat from the scent patch region to the environment with a limited volume of chitin. This study of the correlation between IR emissivity and microstructural designs may offer additional pathways to engineer bioinspired materials and systems for radiative cooling applications.