Synthesis of conjugated monodisperse amphiphilic block copolymers

The synthesis of monodisperse block copolymers for 3-D nanobatteries is the goal of the work presented here. Low polydispersity, below 1.1, is desired in order to facilitate self-assembly of desirable battery architecture. One block is poly(ethylene glycol) (PEG). Poly(ethylene glycol) is designed to serve as an ionic conductor and electrical insulator. The second block copolymer is a conjugated polymer. It is capable of storing charge and is to be used as the battery anode. Three different block copolymer systems were investigated. The first system uses Grubbs catalyst with a successful coupling methodology of norbornylene-terminated PEG to make a block copolymer. However, the instability of the former poly(cyclopentadienylenevinylene) system made it an unattractive material. A second block copolymer made was a substituted poly(p-phenylenevinylene) (PPV)-PEG block copolymer that possesses many desirable properties for a 3-D nanobattery material. The PPV-PEG block copolymer has high solubility, high stability, and a polydispersity index (PDI) of 1.04. PPV was synthesized with PDIs below 1.1, but most reproducibly at the 200 mg scale. Atomic force microscopy (AFM) images of films show the material capable of possessing long range order. The final block copolymer system studied used poly(thiophene) as the conjugated block. A modified synthesis of regioregular poly(3-alkylthiophene) (P3AT) was found as a simple method to afford P3AT with PDIs around 1.1. Coupling of PEG to poly(3-hexylthiophene) (P3HT) was not as efficient as that found in the previous two systems. However, coupling of PEG to poly [3-(2'-ethyl)hexylthiophene] (P3EHT) was synthesized with respectable yields.