Confinement-Induced One-Dimensional Ferroelectric Polymer Arrays

Abstract

This work demonstrates the use of wetting nanoporous alumina template with polymer solution to produce arrays of isolated poly(vinylidene fluoride) (PVDF) ferroelectric gamma-type nanorods supported within a nonpolar alpha-structure film. The method is based upon a crystal phase transition which occurs due to PVDF confinement within alumina nanoporous. The system was studied using scanning X-ray microdiffraction (micro-XRD) that allows the solid-solid phase transition from the alpha-nonpolar crystal form (bulk) to the gamma polar ferroelectric form (nanorod array) to be spatially resolved, as well as providing crystallinity and orientation information. The results reveal that the interaction between polymer chains and the porous membrane's walls imposes a flat-on lamella growth along the nanorrods long axis, while improving crystal orientation.

Superhydrophobicity of Self-Organized Surfaces of Polymer Nanowire Arrays Fabricated by a Nano-Injection Moulding Technique

“…In the present paper, two hours of infiltration may prepare us nanowire arrays with about 50 µm in thickness. Moreover, the vibration does help the polymer chains to be more oriented due to the oscillatory shear rates (23,24) so that the present polymer nanowire arrays also have very high thermal conductivity (more than 10 W/mK) (25) . Fourth, the sample is cooled down to ambient temperature.…”

Electrical characterization of poly(vinylidene fluoride-trifluoroethylene) nanocrystals embedded in porous alumina matrix

“…Peculiarities of producing the array of isolated polymer nanowires were presented in Ref. 19. Piezoelectric behavior of one-dimensional polymer nanowires was observed, upon recording ferroelectric polarization, hysteresis, and displacement loops.…”

Molecular composition distribution of polycarbonate/polystyrene blends in cylindrical nanopores

“…1 Attention has been focused on structure formation processes such as chain dynamics, 2-5 crystallization [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] and phase separation [20][21][22][23][24][25][26][27][28] under the influence of the two-dimensional confinement imposed by cylinder geometry and interfacial interactions with pore walls. Owing to the special shape of nanocylinders with high aspect ratios (length to diameter), the fabricated nanomaterials have unusual mechanical, chemical, optical and electronic properties, as well as specific surface properties.…”

“…1 For amorphous polystyrene (PS) confined in cylindrical alumina nanopores, an unexpected enhancement of flow and a reduction in intermolecular entanglement have been observed, leading to higher mobility of polymer in the confined geometry than that of unconfined chains. 2 In the case of semicrystalline polymers under nanocylindrical geometry, the polymers exhibit novel orientation, [5][6][7][8][9][10][11][12][13][14][15][16][17] polymorphism 18 and segmental dynamic behavior. 5,17 The crystals that form in nanorods at low supercooling show perpendicular orientation; that is, the c-axes of the polymer crystals that develop in cylindrical nanopores preferentially orient perpendicular to the long axis of the nanopore.…”

“…5,17 The crystals that form in nanorods at low supercooling show perpendicular orientation; that is, the c-axes of the polymer crystals that develop in cylindrical nanopores preferentially orient perpendicular to the long axis of the nanopore. [5][6][7][8][9][10][11][12][13][14][15][16][17] The crystallinities [8][9][10] and melting temperatures 10,17 of nanorods are reduced compared with those of bulk polymer, owing to the spatial confinement of the nanopores. Strong deviation from the normal relaxation behavior of poly(vinylidene fluoride) was observed inside nanopores.…”