Precise tuning of the chemical composition of shell cross-linked (SCK) nanoparticles provides systematic control over their environmental interactions, as is demonstrated by regioselective modification of the internal and external chemistries. Hydrolysis of the poly(methyl acrylate) core domain of SCKs composed of poly(acrylic acid-co-acrylamide) shell layers produced entirely hydrophilic, pH responsive nanocage-like structures presenting poly(acrylic acid) chains from the inner cage surface. Two-dimensional, colloidally crystallized nanoarrays of the SCKs and nanocages when sorbed at solid substrate surfaces in the presence of water were substrate dependent and pH tunable.
