Heterostructured Polymer‐Infiltrated Nanoparticle Films with Cavities via Capillary Rise Infiltration

Abstract

Polymer‐infiltrated nanoparticle films (PINFs) that have high volume fractions (>50 vol%) of nanoparticles (NPs) possess enhanced properties making them ideal for various applications. Capillary rise infiltration (CaRI) of polymer and solvent‐driven infiltration of polymer (SIP) into pre‐assembled NP films have emerged as versatile approaches to fabricate PINFs. Although these methods are ideal for fabricating PINFs with homogenous structure, several applications including separations, and photonic/optical coatings would benefit from a method that enables scalable manufacturing of heterostructured (i.e., films with variation in structural properties such as porosity, composition, refractive indices, etc.) PINFs. In this work, a new technique is developed for fabricating heterostructured PINFs with cavities based on CaRI. A bilayer composed of densely packed inorganic NP layer atop polymer NP layer is thermally annealed above the glass transition temperature of the polymer NP, which induces CaRI of the polymer into the interstices of the inorganic NP layer. Exploiting the difference in the sizes of the two particles, heterostructured double stack PINFs composed of a PINF and a layer with large cavities are produced at a moderate temperature (<200 °C). Using these heterostructured PINFs, Bragg reflectors that can detect the presence of wetting agents in water are fabricated.

Conflicting Effects of Extreme Nanoconfinement on the Translational and Segmental Motion of Entangled Polymers

“…Capillary rise infiltration (CaRI) of polymers into the interstitial pores of nanoparticle (NP) packings ,,,− has emerged as a powerful approach to prepare nanocomposite films and membranes with extremely high volume fractions of nanomaterials. Such polymer-infiltrated NP films have superb fracture toughness, thermal stability, and corrosion resistance. ,,, In addition to material fabrication, infiltration of high-molecular-weight (MW) polymers into nanopores is an important step in enabling upcycling of polymers through heterogeneous catalysis …”

“…Such polymer-infiltrated NP films have superb fracture toughness, thermal stability, and corrosion resistance. 3,17,21,22 In addition to material fabrication, infiltration of high-molecular-weight (MW) polymers into nanopores is an important step in enabling upcycling of polymers through heterogeneous catalysis. 23 In many instances, polymer chains undergoing capillary rise into nanoporous media are subjected to extreme nanoconfinement as chains are confined to pores that are substantially smaller than their unperturbed chain dimensions.…”

The Interplay of Polymer Bridging and Entanglement in Toughening Polymer-Infiltrated Nanoparticle Films

“…In this work, we investigate the effect of polymer chain confinement on the fracture behavior of composites consisting of dense packings of silica NPs infiltrated with a glassy polymer, polystyrene. These highly loaded composites are prepared by a recently developed capillary rise infiltration (CaRI) technique, which takes advantage of capillarity-induced imbibition of polymer into the interstices of dense packings of NPs. − This method overcomes the difficulties associated with mixing and stabilizing a large amount of nanofillers in a polymer matrix using conventional methods such as solution mixing or melt compounding. ,,, CaRI has been applied to a wide range of polymers and NPs , and enables the fabrication of PINFs for various applications including Bragg reflector sensors, oil/water separation, , and anticorrosive coatings . Moreover, CaRI is a powerful approach to fabricate materials that can be used to investigate polymer behavior under extreme confinement.…”

“…35−38 This method overcomes the difficulties associated with mixing and stabilizing a large amount of nanofillers in a polymer matrix using conventional methods such as solution mixing or melt compounding. 2,11,34,39 CaRI has been applied to a wide range of polymers and NPs 40,41 and enables the fabrication of PINFs for various applications including Bragg reflector sensors, 42 oil/water separation, 43,44 and anticorrosive coatings. 45 Moreover, CaRI is a powerful approach to fabricate materials that can be used to investigate polymer behavior under extreme confinement.…”

Self-Assembled Honeycomb Lattices of Dielectric Colloidal Nanospheres Featuring Photonic Dirac Cones

“…After complete evaporation, the substrate is annealed above T g of the polystyrene, in which the polystyrene patterns are slightly melted and hold the bottom layer of the silica nanospheres. 30 The substrate is cooled to room temperature and sonicated for 40 s for removing the upper layers from the substrate except the bottom layer which is held by the polystyrene pattern. Therefore, we can fabricate the honeycomb lattice with silica nanospheres.…”