Orientation of Syndiotactic Polystyrene Crystallized in Cylindrical Nanopores

Abstract

Syndiotactic polystyrene (sPS) nanorods with different diameters have been prepared by using anodic aluminum oxide templates, and the orientation of the sPS crystals in the nanorods has been investigated by FT-IR spectroscopy. It is found that the c axis of the β' crystals preferentially oriented perpendicular to the axis of the nanorod, and the degree of orientation is lower as the diameter of the nanorod decreases. This unexpected result is attributed to nuclei formed at the surface of the nanopores and their subsequent growth, in addition to the preferential growth compatible with the pore direction by the nuclei formed in the bulk film and in the nanorods.

Confinement Induced First Order Crystallization Kinetics for the Poly(ethylene oxide) Block within A PEO‐b‐PB Diblock Copolymer Infiltrated within Alumina Nano‐Porous Template

“…On the other hand, once the copolymer is infiltrated in the AAO nanopores, confinement causes a dramatic reduction of the PEO block crystallization temperature. A similar behavior has been reported for PEO and other polymers that have been infiltrated in AAO templates, like PP, PE, sPS and PVDF . In the case of diblock copolymer within a 35 nm AAO template, the crystallization temperature of the PEO block experience a reduction of 72.2 °C upon infiltration of the material.…”

Control of zinc oxide nanowire array properties with electron-beam lithography templating for photovoltaic applications

“…The Herman's order parameter S 〈 〉 , where φ is the deviation angle between the nanowire and the substrate normal, is a widely used measure of the preferential alignment [4,33,34]. As shown in Figure 3b, φ was measured from SEM micrographs of nanowire arrays taken at 45 o tilt (see SI for a detailed description of measurement method and discussion of geometric transformation).…”

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.…”