Intermolecular interactions between sol–gel-derived random-structure oligomeric silsesquioxanes and a diazonaphthoquinone derivative

Abstract

Oligomeric silsesquioxanes (Oligo-SQs) with random structures featuring phenyl (Ph) groups or both Ph and methyl (Me) groups as their substituents were synthesized by the sol–gel method. The ratio of Ph and Me groups controlled the molecular weights and branching in the Oligo-SQs. Branching increased as the molecular weight increased (when the alkaline dissolution rates of all Oligo-SQs adjusted to ∼40 nm s−1). A diazonaphthoquinone (DNQ) derivative was added to the Oligo-SQs to impart positive photosensitivity. A Ph content ratio of over 50 mol% was found to be necessary for the Oligo-SQs to exhibit DNQ compatibility and good patterning performance. Infrared absorption spectroscopy analysis and density functional theory calculations indicated the formation of novel aromatic siloxane DNQ aggregates upon hydrogen bonding between hydroxyl group domains in the Oligo-SQ (formed by hydroxyl groups bonded to Si on adjacent Ph moieties) and the DNQ derivative, which adopts only one of its possible resonance structures.

High-Refractive-Index Photosensitive Siloxane Coatings for Optical Fingerprint Sensor

“…As shown in Table 1, the siloxane polymer solutions (Si-POLY-0, 1) were prepared in DAA using a phosphoric acid catalyst by the sol-gel method using Me-TMS (T unit)/Ph-TMS (T unit)/Nap-TMS (T unit)/DMe-DMS (D unit) with molar ratios of 50/30/20/0 and 30/30/20/20 in accordance with the preparation procedure described in our previous report [22].…”

Dissolution Behavior of Fluoroalkylated Diazonaphthoquinone and Its Blends with Fluorinated Copolymers under UV Irradiation

“…DNQbased photoresists are a type of nonchemically amplified photoresists that do not depend on an acid-catalyzed deprotection reaction for solubility change. Generally, they consist of a mixture of DNQ derivatives and a novolak resin, a phenol-formaldehyde condensation polymer [28][29][30][31][32][33][34]. Novolak resin contributes to the formation of rigid photoresist films that are washed away in an aqueous base solution because it has acidic phenolic hydroxyl groups.…”

Deposition of organic–inorganic hybrid polymer thin films with a silsesquioxane unit

“…They are compatible with organic polymers, while possessing resilience to thermal and mechanical stress owing to the silica core. 8,9) Thin films consisting of silsesquioxanes have been utilized for constructing nanostructures, 10,11) silicon microelectronics, 12,13) as well as organic devices. 14,15) These films are prepared by the sol-gel method that requires a thermal annealing process.…”