| dc.description.abstract | Abstract
Three-dimensional (3D) network templates show great potential and interest in the fabrication of electronic devices, electrocatalysis, and supercapacitors. The 3D-network templates provide favorable characteristics, such as high specific surface area, high mass, and diffusion transfer. In this work, we report a simple method to fabricate 3-D micelle networks through self-assembly of mixtures of polystyrene-block-poly(ethylene) (PS-b-PEO) and dopamine (DA) in solution. Mixtures are dissolved in two different co-solvents, THF/water, and DMF/water, respectively, followed by HCl addition HCl addition not only enhances charge−dipole interactions between PEO and DA but also prohibits the oxidation reaction of DA in solution. In addition, HCl can increase the effective Flory-Huggins parameter of PS-b-PEO for the mixtures and triggers formation of a gel-like structure in the DMF/water system. Two-steps are necessary to induce the sol−gel transition. First, low-molecular-weight (low-Mw) PS-b-PEO formed core-shell micelles in co-solvent. Second, deformed micelles were obtained by adding HCl. Patchy micelles were formed and acted as cross-linking points for gelling. The gel structure is a 3-D micellar network with hydrophobic channels. The network framework evolved from patchy micelles. Upon drying from THF/water co-solvent, micelles of low-Mw PS-b-PEO formed onion-like vesicles . In contrast, the 3-D gel structure could support the porous framework that had formed in DMF/water co-solvent. DA oxidative polymerization was induced by NH4OH vapor. It was found that 3-D porous structure of BCP/PDA mixtures remained unchanged after DA polymerization for the micelles in DMF/water. Nevertheless, 3-D porous networks could collapse after carbonization at a high temperature. | en_US |