Spherulitic fiber networks

Enhanced side branching of fibers by surfactant molecules was also observed. It was observed that the presence of a surfactant Span 20 could enhance the side branching of GP-1 fibers formed in propylene glycol (PG), which converts spherulitic fiber structures into comb-like and brush-like fibers when the surfactant concentration is below 0.77 wt% (Figure 2.8c-e) [4a]. With increase of surfactant concentration to above its critical micelle concentration (CMC) of 1.5 wt% in PG, the fiber network was converted back into a spherulitic fiber network (Figure 2.8f). However, the spherulitic fiber network formed in the presence of the surfactant is denser, and the elasticity of the material is twice that in the absence of surfactant. 

Note that the primary nucleation of fibers is normally governed by heterogeneous nucleation. Figure 3 shows the initiation of an N-lauroyl-L-glutamic acid di- -butylamide (GP-1) a fiber network (spherulite) from a nucleation center. 

Figure 2.11 Conversion of a multi-domain fiber network to a single fiber network through thermal processing (a,b) and ultrasound-assisted fiber network formation (c,d). (e) Schematic description of the formation of GP-1 spherulites through the normal thermal processing and the formation of an interconnecting fiber network through a seeded process with either thermal or mechanical (i.e., ultrasonic) stimuli. For thermal processing, T,. > > Tj > Tj to ensure the...

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