These results indicate amide groups have a greater relative contribution to the spectra at low PS loading whereas carboxylate groups' relative contribution to the spectra is highest at high PS loading. The initial appearance of the amide groups (the amphiphilic component of PS), followed by the methyl ester groups, indicates the formation of multiple intramolecular hydrogen bonds between the NH2 + and C=O moieties of alkylamide and methylester groups on the diamond.