Innovative Temperature-Responsive Fluorescent Hydrogel for Smart Windows and Advanced Environmental Sensing

School Name

Spring Valley High School

Grade Level

11th Grade

Presentation Topic

Chemistry

Presentation Type

Non-Mentored

Abstract

The presented study described the synthesis, characterization, and temperature-responsive fluorescence behaviour of a dual-chromophore double-network hydrogel (DNH) that incorporates poly(N-isopropylacrylamide) (PNIPAM) covalently crosslinked with fluorescein diacrylate (FL-DA), as a primary network, followed by the formation of a secondary poly(2-acrylamido-2-methylpropanesulphonic acid) (PAMPS) network incorporating fluorene diacrylate (FR-DA) as a second covalently-integrated chromophore. The thermoresponsive PNIPAM/PAMPS hydrogel had a dual-wavelength signaling and mechanically robust structure that could be used for environmental sensing, innovative thermal coatings, and smart surface applications. The temperature-dependent fluorescence spectra were recorded from 5 °C to 60 °C and exhibited two emission bands characteristic of the two chromophores. The increase in temperature produced a decrease in band intensity and a red shift. The short-wave emission characteristic of FR-DA exhibited wavelength shifts of 9 nm and 8 nm, corresponding to overall increases of 2.91% and 2.49%, respectively. FL-DA exhibited a long-wave emission peak that shifted to red by 14 nm, from 511 to 525 nm, corresponding to a 2.74% increase in wavelength over the 5 to 60 OC temperature range. The one-way ANOVA showed F(11, 3600) = 2.20, p < 0.012. A post hoc Tukey test confirmed that the control condition (25 °C) differed across all temperature groups. The increase in temperature altered the degree of polymer hydration, increased chain mobility, and altered chromophore orientation, leading to enhanced non-radiative relaxation and spectral changes. The PNIPAM network undergoes a coil-to-globule transition, which produces a pronounced inflection in the overall fluorescence behavior.

Location

Furman Hall 107

Start Date

3-28-2026 11:45 AM

Presentation Format

Oral and Written

Group Project

No

COinS
 
Mar 28th, 11:45 AM

Innovative Temperature-Responsive Fluorescent Hydrogel for Smart Windows and Advanced Environmental Sensing

Furman Hall 107

The presented study described the synthesis, characterization, and temperature-responsive fluorescence behaviour of a dual-chromophore double-network hydrogel (DNH) that incorporates poly(N-isopropylacrylamide) (PNIPAM) covalently crosslinked with fluorescein diacrylate (FL-DA), as a primary network, followed by the formation of a secondary poly(2-acrylamido-2-methylpropanesulphonic acid) (PAMPS) network incorporating fluorene diacrylate (FR-DA) as a second covalently-integrated chromophore. The thermoresponsive PNIPAM/PAMPS hydrogel had a dual-wavelength signaling and mechanically robust structure that could be used for environmental sensing, innovative thermal coatings, and smart surface applications. The temperature-dependent fluorescence spectra were recorded from 5 °C to 60 °C and exhibited two emission bands characteristic of the two chromophores. The increase in temperature produced a decrease in band intensity and a red shift. The short-wave emission characteristic of FR-DA exhibited wavelength shifts of 9 nm and 8 nm, corresponding to overall increases of 2.91% and 2.49%, respectively. FL-DA exhibited a long-wave emission peak that shifted to red by 14 nm, from 511 to 525 nm, corresponding to a 2.74% increase in wavelength over the 5 to 60 OC temperature range. The one-way ANOVA showed F(11, 3600) = 2.20, p < 0.012. A post hoc Tukey test confirmed that the control condition (25 °C) differed across all temperature groups. The increase in temperature altered the degree of polymer hydration, increased chain mobility, and altered chromophore orientation, leading to enhanced non-radiative relaxation and spectral changes. The PNIPAM network undergoes a coil-to-globule transition, which produces a pronounced inflection in the overall fluorescence behavior.