What Happens to Polymer Chains Confined in Rigid Cylindrical Inorganic (AAO) Nanopores

Abstract

Nanoconfinement can profoundly change the bulk characteristics. The question of conformational changes under one-dimensional confinement is recurrent in polymer physics. Very few works addresses this question because of the hard experimental challenge and the complex analysis of the signal. Here, the conformation of polystyrene chains shaped by wetting, in nanotubes or nanorods is for the first time determined at 3 dimensions. Polystyrene chains (molecular weight samples from 38 kDa to 310 kDa) confined in AAO nanopores as large as the size of the pore diameters (from 35 to 180 nm) are probed, revealing the invariance with respect to the bulk-like conformation for polystyrene chains up to 301 kDa confined down to 35 nm diameter nanopores.

Crystallization and orientation of isotactic poly(propylene) in cylindrical nanopores

“…Several previous studies have shown successful wetting of nanoporous anodic aluminum oxide (AAO) templates with various polymers . Nanoporous AAO templates bear cylindrical pores of tunable diameter and length.…”

“…Several previous studies have shown successful wetting of nanoporous anodic aluminum oxide (AAO) templates with various polymers. [11][12][13][14][15][16][17][18][19][20][21][22] Nanoporous AAO templates bear cylindrical pores of tunable diameter and length. Bulk PEO was shown to nucleate heterogeneously; however, homogeneous nucleation dominated when confined in AAO nanopores 200 nm in diameter or smaller.…”

Dependences of Confining Size and Interfacial Curvature on the Glass Transition of Polydimethylsiloxane in Self‐Assembled Block Copolymers

“…Such results indicate that the variations of T g are also depending on shape of confining geometries. To better understand the influences of geometrical difference on glass transition dynamics, many studies have focused on extending research beyond planer system to other geometric shapes such as nanotubes or nanobowls . More recently, a work by Xue and co‐workers demonstrated that the interfacial effect on the glass transition of polymers confined in nanotubes was imposed by hard wall with a concave geometry .…”

“…To better understand the influences of geometrical differ ence on glass transition dynamics, many studies have focused on extending research beyond planer system to other geometric shapes such as nanotubes or nanobowls. [39][40][41][42] More recently, a work by Xue and coworkers demonstrated that the interfacial effect on the glass transition of polymers confined in nanotubes was imposed by hard wall with a concave geometry. [12] In our system, different confining geometries have different polymer-polymer interfacial curvatures, therefore, we propose that the effect of confining geometries on T g is mainly due to the different curvature of PDMS-PMPCS interface.…”

Polymer dynamics in nanoconfinement: Interfaces and interphases

“…However, the screening of intrachain excluded volume interactions progressively diminish with decreasing film thickness resulting in a chain swelling in direction perpendicular to the interfaces [6]. In contrast, in cylindrical nanopores the absence of chain anisotropy in this configuration was recently observed [7].…”