Figure 1. Layer-by-layer assembly of (PrS/SPS)n PEMs.
Substrate is first submerged in the polycation solution, protamine sulfate (PrS); 21 of 32 amino acids are arginine, R. Following a rinse in deionized water, the PrS-coated substrate is then immersed in the polyanion solution, sodium (4-sulfonated poystyrene) (SPS), followed by another water rinse.