Small molecules binding, polyethyleneimine

Fluorescent nanotubes of polyethyleneimine (PEI) and 3,4,9,10-perylenetetra-carboxylicdianhydride (PTCDA) have been prepared through the alternating deposition of polymers and small functional molecules that form covalent bonds (Figure 7.10) [ 120]. The nanotube synthesis starts with the deposition of P EI in the pores of an AAO membrane as the first layer. The PTCDA solutionis then used to bind to the PEI via covalent bonding (Figure 7.10). The electro-optical properties of the small molecule (PTCDA) are retained in the multilayer films of PEI/PTCDA. The prepared nanotubes retain their fluorescent properties for up to 10 months without... 

The polymer was 10 times as effective as a small-molecule analog, dimethy-benzylamine 10 in the case of p-nitrophenyl caproate 6. The rate enhancement is larply attributed to favorable binding. No difference in catalytic activity was found between linear and branched polyethyleneimine derivatives. It is curious that desorption of the product is rate-limiting according to the kinetic analysis. 

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