化工专业英语求翻译

Hollow polymeric spheres have been attracting increasing interest because of their potential applications， which range from targeted drug delivery to advanced functional materi- als.[1，2] Because of their hollow core structure， such poly... Hollow polymeric spheres have been attracting increasing interest because of their potential applications， which range from targeted drug delivery to advanced functional materi- als.[1，2] Because of their hollow core structure， such polymeric spheres can encapsulate large quantities of guest moleculesÐ especially those spheres with functionalities within the empty coreÐand release them at a later stage in a controlled man- ner. Although hollow polymeric spheres with dimensions in the micrometer and submicrometer regions are readily con- structedÐby layer-by-layer deposition of polyelectrolytes onto a template core，[3±6] polymerizing monomers in lipid vesi- cles，[7，8] emulsion polymerization，[9，10] pH-induced micelliza- tion of a grafted copolymer，[11] and by the assembly of posi- tively charged polyelectrolytes and negatively charged nanoparticles[12]Ðthe synthesis of hollow spheres 100 nm or less in size has only recently become the subject of research activity. Several different routes， such as the self-assembly of block copolymers in a selective solvent，[13，14] the deposition of polyelectrolytes on a decomplexable or soluble core，[15，16] and microemulsion (as well as miniemulsion) polymerization，[17，18] have been developed to form hollow polymeric nanospheres. Although some of these methods have been quite successful， these strategies require the core templates to be removed in order to create a hollow interior， or need large quantities of surfactants to form nanosized micelles. Furthermore， although the majority of the proposed applications of hollow nano- spheres or nanocapsules are concentrated in the biomedical field， most of the hollow polymeric spheres described to date are ill-suited for such purposes. Therefore， materials (in par- ticular for the surfaces of the hollow nanospheres) that are biocompatible， non-toxic， and sometimes also biodegradable， are highly desirable. Herein， we demonstrate a simple and di- rect method for fabricating hollow polymeric nanospheres with biocompatible and biodegradable macromolecules. In this approach， hollow polymeric nanospheres were formed in a completely aqueous system without the aid of surfactants，