Next Article in Journal
Effects of Covalent Functionalization of MWCNTs on the Thermal Properties and Non-Isothermal Crystallization Behaviors of PPS Composites
Next Article in Special Issue
The Chemistry and Physics of Bayfol® HX Film Holographic Photopolymer
Previous Article in Journal
Physico-Chemical Properties of Soybean Meal-Based Adhesives Reinforced by Ethylene Glycol Diglycidyl Ether and Modified Nanocrystalline Cellulose
Previous Article in Special Issue
Light-Up of Rhodamine Hydrazide to Generate Emissive Initiator for Polymerization and to Afford Photochromic Polypeptide Metal Complex
Article Menu
Issue 9 (September) cover image

Export Article

Open AccessArticle
Polymers 2017, 9(9), 462; https://doi.org/10.3390/polym9090462

Photochromic Polyurethanes Showing a Strong Change of Transparency and Refractive Index

1
INAF—Osservatorio Astronomico di Brera, via Bianchi 46, 23807 Merate, Italy
2
Dipartimento di Chimica, Materiali ed Ingegneria Chimica, Politecnico di Milano, p.zza L. Da Vinci 32, 20133 Milano, Italy
3
OPTMATLAB, Dipartimento di Fisica, Università degli Studi di Genova, Via Dodecaneso 33, 16146 Genova, Italy
4
Center for Nano Science and Technology, @PoliMi, Istituto Italiano di Tecnologia, Via Pascoli 70/3, 20133 Milano, Italy
*
Author to whom correspondence should be addressed.
Received: 4 August 2017 / Revised: 2 September 2017 / Accepted: 13 September 2017 / Published: 20 September 2017
(This article belongs to the Special Issue Photo-Responsive Polymers)
View Full-Text   |   Download PDF [3982 KB, uploaded 20 September 2017]   |  

Abstract

Photochromic polymers have been studied as rewritable systems for optical elements with tunable transparency in the visible and refractive index in the NIR. Six diarylethene monomers have been synthesized to give thin films of photochromic polyurethanes. The absorption properties of the monomers in solution and of the corresponding polymeric films have been evaluated showing that a transparency contrast in the visible spectrum of the order of 10 3 can be obtained by a suitable choice of the chemical structure and illumination wavelength. The change in the refractive index in the NIR have been determined by ellipsometry showing changes larger than 10 2 . A trend of this variation with the absorption properties has been also highlighted. Fresnel lenses working on the basis of both a change of the transparency and the refractive index (amplitude and phase) have been demonstrated. View Full-Text
Keywords: photochromism; diarylethenes; polyurethanes; refractive index; holography photochromism; diarylethenes; polyurethanes; refractive index; holography
Figures

Graphical abstract

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).
SciFeed

Share & Cite This Article

MDPI and ACS Style

Oggioni, L.; Toccafondi, C.; Pariani, G.; Colella, L.; Canepa, M.; Bertarelli, C.; Bianco, A. Photochromic Polyurethanes Showing a Strong Change of Transparency and Refractive Index. Polymers 2017, 9, 462.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Polymers EISSN 2073-4360 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top