http://www2.uwstout.edu/content/lib/the ... ersons.pdf
This thesis has some interesting content on various haze-causing compounds (proteins & polyphenols) and the effectiveness of two fining agents (Silica Gel & PVPP). The results of the study are pretty narrowly focused, but the background info given in pgs 22-41 (of the text, not the PDF page numbers) is fascinating. Fining reaction models are explained in more detail than the traditional charge-based approach (e.g. "proteins are negatively charged and require a positively charged agent to precipitate them") often seen in homebrew texts. According to the thesis, Silica Gel will precipitate haze-causing proteins/polyphenols complexes, while PVPP (Polyclar) will precipitate higher molecular weight polyphenols/tannins, which may or may not actually reduce haze.