Analysis of Vicinal Water in Soft Contact Lenses Using a Combination of Infrared Absorption Spectroscopy and Multivariate Curve Resolution

• Published in: Molecules (Basel, Switzerland) Vol. 27; no. 7; p. 2130
• Main Authors: Maeda, Shoichi, Chikami, Shunta, Latag, Glenn Villena, Song, Subin, Iwakiri, Norio, Hayashi, Tomohiro
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 25.03.2022; MDPI
• Subjects: Absorption spectroscopy; Contact lenses; Contact Lenses, Hydrophilic; hydrogel; Hydrogels; Hydrogels - chemistry; Hydrogen bonding; Infrared absorption; infrared absorption spectroscopy; Infrared spectroscopy; molecular vibration; Multivariate analysis; multivariate curve resolution; Polymers; soft contact lenses; Spectrophotometry, Infrared; water; Water - analysis; United States > US; Japan; San Ramon California; soft contact lenses; hydrogel; infrared absorption spectroscopy; molecular vibration; soft material; multivariate curve resolution; water
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules27072130

In this paper, we propose a new spectroscopic method to explore the behavior of molecules near polymeric molecular networks of water-containing soft materials such as hydrogels. We demonstrate the analysis of hydrogen bonding states of water in the vicinity of hydrogels (soft contact lenses). In this method, we apply force to hydrated contact lenses to deform them and to modulate the ratio between the signals from bulk and vicinal regions. We then collect spectra at different forces. Finally, we extracted the spectra of the vicinal region using the multivariate curve resolution-alternating least square (MCR-ALS) method. We report the hydration states depending on the chemical structures of hydrogels constituting the contact lenses.