Recent Progress on Designable Hybrids with Stimuli‐Responsive Optical Properties Originating from Molecular Assembly Concerning Polyhedral Oligomeric Silsesquioxane

Abstract

In this review, we describe recent progress on stimuli-responsive hybrid materials based on polyhedral oligomeric silsesquioxane (POSS) and their applications as a chemical sensor. In particular, we explain the unique functions originating from molecular assembly concerning POSS-containing soft materials mainly from our studies. POSS has an inorganic cubic core composed of silicon-oxygen (SiÀ O) bonds and organic substituents at each vertex. Owing to intrinsic properties of POSS, such as high thermal stability, rigidity, and low chemical reactivity, various robust hybrid materials have been developed. From the numerous numbers of POSS hybrids, we herein focus on the environmentsensitive optical materials in which molecular assembly of POSS itself and functional units connected to POSS should be a key factor for expressing material properties. We also explain the mechanisms of chemical sensors originating from these stimuli-responsive optical properties. Stimuli-responsive excimer emission and pollutant detectors, nanoplastic sensors with the water-dispersive POSS networks, trans fatty acid sensors, turn-on luminescent sensors for aerobic condition and fluoride anion sensors are described. We also mention the mechanochromic polyurethane hybrids and the thermally-durable mechanochromic luminescent materials. The roles of the unique optical properties from soft materials composed of rigid POSS, which doesn't have significant lightabsorption and emission properties in the visible region, are surveyed.

AB-type monomer of polyhedral oligomeric silsesquioxane

“…2 Among these, the cage-type silsesquioxane, known as polyhedral oligomeric silsesquioxane (POSS), stands out for its suitability for precise molecular design. 3 Polymers containing POSS are typically categorized into four types based on the point of introduction: main chains, 4 side chains, 5 end points, 6 and cross-linking points. 7 Of these, main chain-type POSS polymers have garnered significant attention owing to their superior performance and distinctive properties.…”

Metallodendrimers Unveiled: Investigating the Formation and Features of Double-Decker Silsesquioxane-Based Silylferrocene Dendrimers

“…SQs exhibit exceptional thermal stability and tunable properties, making them attractive for use in fields such as catalysis, nanomaterials, coatings, and energy storage. Furthermore, their ability to integrate organic and inorganic components provides a platform for tailoring properties and designing advanced materials with enhanced performance and multifunctionality. − There are some reports of the conjunction of silsesquioxane with ferrocene in diverse combinations, e.g., to form amphiphilic systems, grafted copolymers with magnetic properties, or porous materials for dye/heavy metal absorption features. ,,,,,− Some of these systems exhibit interesting electrochemical properties, influencing their application. On the contrary, the distinct types of dendrimer cores should be also mentioned, but there are significantly lower numbers of papers concerning silsesquioxane-based dendrimers using ferrocene moieties as terminal fragments. ,, …”

Synthesis of Pyrene-Substituted Azobenzene Derivatives and Their Assembly into Flat Structures for Stimuli-Induced Switching

“…External stimuli-responsive fluorescent materials are of great interest because of their promising utilization in optoelectronic devices, sensors, photopatterning, biomedical delivery, and therapy systems [1][2][3][4][5][6][7][8][9][10][11][12][13]. A number of studies have been reported on the design of organic, inorganic, and organic-inorganic hybrid systems that respond to external or internal stimuli such as light, heat, force, magnet, electricity, specific chemicals, etc [5,[14][15][16][17][18][19][20][21][22].…”