Anchoring of polyelectrolyte membrane containing chalcone group to electrode substrate by [2+2] cycloaddition and its humidity-sensing properties

Abstract

New chalcone group-containing acrylic copolymers were prepared by the copolymerization of [3-(acrylamido)propyl]trimethyl ammonium chloride (APTAC), methyl methacrylate (MMA), and 4-methacryloyloxyphenyl styryl ketone (MPSK) for use as humidity-sensitive polyelectrolytes. The copolymers were self-crosslinkable terpolymers with different contents of APTAC /MMA/MPSK=70/27/3, 70/25/5, 70/23/7, and 70/20/10. Pretreatment of an alumina substrate with 4,4'-bis(3-triethoxysilyl)propoxy chalcone (BTSPC) containing an alkoxysilane-coupling agent was performed to attach the humidity-sensitive polyelectrolyte to it through covalent bonds. The sensors were irradiated with UV light, causing the electronically excited chalcone molecules to undergo a crosslinking reaction via [2π + 2π] addition. After soaking in water for 24 h, the resulting sensor using BTSPC showed water durability and a 42~65% increase in resistance, corresponding to a 2.25~2.98%RH decrease in relative humidity. The sensor showed good hysteresis (-0.2%RH), an acceptable response time (80 sec) and good stability at high temperatures and humidity.

Water-resistive humidity sensor prepared by printing process using polyelectrolyte ink derived from new monomer

“…It has been found that these systems can be successfully sensitized towards UV and visible light. [22][23][24][25][26] The rheological properties of polyelectrolyte ink are specifically tailored for the printing process, which involves ink discharge through a fine screen that is automatically controlled using a blade. Central to this approach is the design of inks that are capable of flowing through a screen and then set immediately to facilitate shape retention of the deposited feature.…”

Photochemical anchoring of polyelectrolyte to the electrode surface using polymeric silane-coupling agents and their water durability

“…4-Acryloxybenzophenone (BPA) was prepared by the method previously reported. 33 [2-(Acryloyloxy)ethyl]trimethylammonium chloride (AETAC) was purchased from Aldrich Chem. Co. 3-(Trimethoxysilyl)propyl methacrylate (TMSPM), styrene (ST), 2-hydroxyethylacrylate (HEA) and azobisisobutyronitrile (AIBN, Aldrich Chem.…”

“…[25][26][27][28] A few studies on the photocurable anchoring of the polyelectrolyte to the surface of the electrode substrate for the durability in water were reported. [27][28][29][30][31][32][33][34][35] Photoinduced crosslinking is rapidly expanding technology on pressure-sensitive adhesive, printing ink, photoresist and biomaterials resulting from its main advantages such as solvent-free process, efficient and economical energy used and new properties and quality of chemical crosslinking. [36][37][38][39] This technology is applied to a self-crosslinkable polymer system suitable for absorbing light radiation of the appropriate wavelength and producing primary radical species in order to attach a polymer layer into a solid substrate.…”

Diels–Alder cycloadditions of fullerene: Advances in mechanistic theory

“…Typical cycloadditions are [4 + 2], [2 + 2], and [3 + 2] reactions, but there are numerous others. [20][21][22][23] In addition, square brackets can also be used to indicate the number of electrons involved in the product formation process, rather than the number of carbon atoms. One such transformation is the Diels-Alder (DA) reaction, a thermally allowed [4 + 2] cycloaddition with the Woodward-Hoffmann symbol [π4 s + π2 s ].…”