Solution‐Processed Ultrathin Aluminosilicate Nanotube–Poly(vinyl alcohol) Composite Membranes with Partial Alignment of Nanotubes

Abstract

The fabrication of ultrathin (300 nm) aluminosilicate nanotube-poly(vinyl alcohol) composite membranes with partial vertical alignment of the nanotubes (up to 33 %), by solution-casting methods on porous polymeric substrates, is reported. Ah igh loading (up to 60 vol %) of nanotubes is achieved. Ac omprehensive microstructural characterization of the membranes is performed by ac ombination of SEM, TEM, grazing-incidence wide-angle X-ray scattering measurements, and simulations. This investigation shows that the nanotubes are individually dispersed and partially aligned in the polymeric matrix by the use of appropriate matrix and substrate materials. Permeation measurements of gas probe molecules (CO 2 and CH 4 )o nt wo different types of membranes, one containing bare nanotubes and the other containing amine-functionalized nanotubes, also support the proposed microstructure of the thin nanocomposite membranes.[a] Prof.

Defective Single‐Walled Aluminosilicate Nanotubes: Structural Stability and Mechanical Properties

“…AlSiNTs comprise a crystalline structural topology (Figure ) with an empirical formula of (HO) 3 Al 2 O 3 SiOH possessing a monodispersed pore size of approximately 1 nm with functionalizable interior surfaces . High dispersity makes AlSiNTs amenable to aqueous‐phase processing and compatible with hydrophilic polymeric materials, such as poly(vinyl alcohol) . Several computational studies have reported that AlSiNTs possess a Young's modulus of approximately 340 GPa and a shear modulus of 160 GPa .…”

“…[26,27] High dispersity makes AlSiNTsa menable to aque-ous-phase processing and compatible with hydrophilic polymeric materials, such as poly(vinyl alcohol). [28,29] Several computationals tudies have reported that AlSiNTsp ossessaYoung's modulus of approximately 340 GPa and as hear moduluso f 160 GPa. [23][24][25]30] However,t hese calculations are based on ad efect-freec rystalline model,w hich is very likely to overestimate the actual mechanical strength.…”

Imogolite Nanotubes: A Flexible Nanoplatform with Multipurpose Applications

“…Poly(vinyl alcohol) (PVA) is by far the most used polymeric material since PVA/INT can be processed easily from aqueous solutions. In most cases, the mechanical and optical properties of the resulting composite are enhanced, whether in film [84,[128][129][130][131], fiber [132] or membrane form [133][134][135] (Figure 7a). Beyond PVA, INT has been incorporated in a wide variety of polymer matrix (Table 3) either for nanotube-reinforced nanocomposites [90,96,100,138,143,149,150] with anisotropic structural properties (Figure 7b) [93,94,97,136,137,144,148,151,152], fabrication of hierarchical porous structures [139][140][141][142] or the encapsulation/sustained-release of biomolecules for medical applications (Figure 7c) [153][154][155][156][157][158][159].…”

Highly selective mixed-matrix membranes with layered fillers for molecular separation

“…In the initial development of MMMs, only nearly spherical microporous materials were used as fillers [26,31]. In recent years, low-dimensional (1D and 2D) porous materials, such as nanotubes (1D) [32][33][34][35] and layered porous materials (2D) [36][37][38], have been regarded as emerging filler materials. Layered porous materials could potentially outperform near-spherical ones for use as filler in MMMs, for two reasons.…”