Delayed luminescence induced by complex domains in water and in aqueous solutions

TL;DR

This study investigates the complex structure of water and aqueous solutions using delayed luminescence, revealing domain formation and energetic differences influenced by silica gel (TEOS) presence.

Contribution

It introduces the use of delayed luminescence to probe domain structures in water and solutions, highlighting differences caused by silica gel (TEOS).

Findings

Photon emission follows an Arrhenius trend with higher activation energy in water-TEOS solutions.

A consistent intrinsic lifetime of about 5 microseconds was observed in solutions and pure water.

TEOS presence induces secondary lifetimes related to domain formation.

Abstract

Many recent studies on water have conjectured a complex structure composed of hydrogen bonded low- and high-density domains. In this work the structure of pure water and aqueous solutions of silica gel (TEOS) has been investigated by using delayed luminescence, which previously have showed significant increase in aqueous salt solutions where low-density domain formation is expected. Photon emission shows an Arrhenius trend with an activation energy in water-TEOS solutions larger than in pure water and salt-water solutions. Moreover, delayed photon emission decay shows an intrinsic lifetime of about 5 microseconds both in solutions and in pure water that, along with secondary lifetimes induced by the presence of TEOS, could be related to the formation of different domains.