Fabrication of multi-level carbon nanotube arrays with adjustable patterns

Abstract

Multi-level carbon nanotube (CNT) arrays with adjustable patterns were prepared by a combination of the breath figure (BF) process and chemical vapor deposition. Polystyrene-b-poly(acrylic acid)/ferrocene was dissolved in carbon disulfide and cast onto a Si substrate covered with a transmission electron microscope grid in saturated relative humidity. A two-level microporous hybrid film with a block copolymer skeleton formed on the substrate after evaporation of the organic solvent and water. One level of ordered surface features originates from the contour of the hard templates; while the other level originates from the condensation of water droplets (BF arrays). Ultraviolet irradiation effectively cross-linked the polymer matrix and endowed the hybrid film with improved thermal stability. In the subsequent pyrolysis, the incorporated ferrocene in the hybrid film was oxidized and turned the polymer skeleton into the ferrous inorganic micropatterns. Either the cross-linked hybrid film or the ferrous inorganic micropatterns could act as a template to grow the multi-level CNT patterns, e.g. isolated and honeycomb-structured CNT bundle arrays perpendicular to the substrate.

Three-Dimensionally Conformal Porous Microstructured Fabrics via Breath Figures: A Nature-Inspired Approach for Novel Surface Modification of Textiles

“…7c). The decoration of TiO 2 NPs on pore walls can be ascribed to the famous Pickering emulsion effect 31 , which prefers driving nanoparticles to be selectively absorbed at the water/solution interface for the stabilization of water droplets during the BF process 32 . When the same casting solution was coated on the fabric by conventional method in ambient conditions, no porous microstructures are observed on the surface of fabric (Fig.…”

Synthesis of poly(ethylene-co-vinyl alcohol)-g-polystyrene graft copolymer and their applications for ordered porous film and compatibilizer

“…In the end, after completely volatilization of solvent and water, a honeycomb sequence alignment structure is formed on the polymer membranes. As the formation of the porous films were influenced by several parameters including relative humidity (R.H.), temperature, solvent, the structure and component of polymers and polymer concentration, and so forth. In this work, the effects of solvent, temperature, molecular weight, and polymer concentration were investigated.…”

Porous Polyelectrolytes: The Interplay of Charge and Pores for New Functionalities

“…microstructures, [38] which can be used to engineer PPMs if one of the BCP blocks is ap olyelectrolyte.A ss uch, av ariety of BCPs consisting of an eutral hydrophobic polystyrene (PS) block and an ionic hydrophilic block (e.g.P AA [37] and P4VP [39] )w ere investigated. Ma and co-workers reported that the hydrophilicity of the PA Ablock was essential to form porous PS-b-PAA films with better regularities and larger pores.…”