Elmer Keiser Bolton
When Wallace Carothers arrived at DuPont in 1928 one of the tasks his group took on was the development of new synthetic fibers for textiles. At that time a number of natural polymers such as latex and cellulose were in common use, rayon as a semisynthetic from nitrated cellulose had recently been improved and begun upending the textile industries, and some fully synthetic polymers such as bakelite were also known and being used for certain applications, but the existing fully synthetic polymers could not be drawn into fibers and spun into thread, so great opportunity existed to manufacture thread and yarn from synthetic polymers to join or replace the existing fibers in the market (natural fibers such as cotton, wool, linen, and silk and artificial fiber in the various recently emerged types of rayon).
Janus particles
This method uses the well-studied methods of producing block copolymers with well-defined geometries and compositions across a large variety of substrates. Synthesis of Janus particles by self-assembly via block copolymers was first described in 2001 by Erhardt "et al." They produced a triblock polymer from polymethylacrylate, polystyrene and low-molecular-weight polybutadiene. The polystyrene and polymethylacrylate formed alternating layers in between which polybutadiene sat in nanosized spheres. The blocks were then cross-linked and dissolved in THF, and after several washing steps, yielded spherical Janus particles with polystyrene on one face and polymethylacrylate on the other, with a polybutadiene core. The production of Janus spheres, cylinders, sheets, and ribbons is possible using this method by adjusting the molecular weights of the blocks in the initial polymer and also the degree of cross-linking.