Fabrication of photochromic hydrogels using an interpenetrating chitosan network

Abstract

The synthesis of a novel interpenetrating chitosan network post‐modified with spiropyran (SP) derivatives has been used to develop photochromic hydrogels. We have synthesized succinyl chitosan polymers containing a considerable number of both amines and carboxylic groups. Their intra/inter molecular amide coupling reactions and postmodification with SP derivatives resulted in the photochromic hydrogels functionalized with chitosan‐based interpenetrating polymer network structures. In this hydrogel system, SPs undergo reversible photoresponsive structural switching between a ring‐closed colorless SP form and a ring‐opened purple merocyanine form under specific light‐irradiation conditions. Notably, the photo‐mediated wettabilities and color intensities of the hydrogels increase by the increment in the molecular weight of SP‐functionalized chitosans. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45120.

Fabrication and Characterization of Eco-Friendly Thin Films as Potential Optical Absorbers for Efficient Multi-Functional Opto-(Electronic) and Solar Cell Applications

“…It is well known that the controllability of the barrier height depends on the characteristics of the inserted organic film between the metal/semiconductor interface, such as its HOMO and LUMO energetic position, and their position relative to semiconductor electron affinity and electrode work function. The obtained values of Φ B0 of all the fabricated devices are higher than those previously recorded for Au/Cs/n-Si (~0.73 eV [23]) and Co/Cs/p-Si (~0.68 eV [13]) but lower than those estimated for Ag/Cs/n-Si (~0.94 eV [22] and Ag/Cs/n-Si (~0.88 eV [12]). The values of shunt resistance, R sh , and series resistance, R s , of the fabricated devices were estimated from the junction's resistance, R j , and plotted, as shown in Figure S8e,f (Supporting Information), respectively.…”

“…On the other side, chitosan has been exploited in many electronic and optoelectronic applications, such as photodiodes [12], thermal sensors [13], Schottky barrier modifier [13,14], resistive random-access memory (RRAM) [15,16], light-emitting diodes [17], humidity sensors [18,19], modulators [20], and optical waveguides, where the lower-molecular-weight chitosan achieved lower loss than that of the higher molecular weight [21]. Additionally, chitosan possessed unique photochromic features [22] and corrosion inhibition [23]. Furthermore, it has been used for fabricating piezoelectric human health sensors [24] and utilized as an electrolyte in dye-synthesized solar cells (DSSCs) [25].…”

Development of Gallic Acid-Modified Hydrogels Using Interpenetrating Chitosan Network and Evaluation of Their Antioxidant Activity

“…As illustrated in Table 1 , a much higher quantity of attached antioxidant residues was found in the hydrogels with a longer MC polymer compared to those with a shorter MC. The longer chitosan seems to produce a more accessible site to GA for the amide coupling reaction as compared to its shorter counterpart, despite that the amounts of incorporated chitosans are nearly same regardless of the length of chitosans [ 16 , 34 ].…”

“…Recently, we demonstrated the potential of IPN structures consisting of succinyl chitosan polymers and spiropyran as photochromic hydrogels [ 34 ]. The nucleophilic amino groups of chitosan polymers within the IPN structure facilitated modifications and conjugations with various functional molecules.…”