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Micelles made by connecting hydrophobic and hydrophilic chains via photo‐responsive ortho‐hydroxy cinnamate (oHC) units undergo complete degradation within 10 min under visible light irradiation at basic pH values. This proof of concept relies on the controlled cyclization of the oHC moiety affording the corresponding coumarin with the concomitant separation of the hydrophobic portion. Furthermore, the neat polymeric micelles are stable under daylight conditions, thus allowing its storage without special precautions at neutral pH. The amphiphilic nature of mPEG750‐oHC‐dodecyl, expressed as the ability to self‐assemble into micellar aggregates in aqueous media, was corroborated by the measurement of its critical micellar concentration (CMC) by fluorescence analysis, as well as the successful visualization of these aggregates using transmission electron microscopy (TEM). Moreover, the size distribution and suspension stability of these aggregates obtained at different pH values was analyzed in terms of dynamic light scattering (DLS) and zeta potential measurements. [ABSTRACT FROM AUTHOR]

The recent demand for fluorescent‐labeled materials (FLMs) in forensic security concepts such as latent fingerprints (LFs) that encode information for anti‐counterfeiting and encryption of confidential data makes necessary the development of building new and innovative materials. Here, novel FLMs based on polyhedral oligomeric silsesquioxanes (POSS) functionalized with fluorophores via "click" reactions have been successfully synthesized and fully characterized. A comprehensive study of their photophysical properties has displayed large Stokes's shift together with good photostability in all cases, fulfilling the fundamental requisites for any legible LF detection on various surfaces. The excellent performance of the hetero‐bifunctional FLM in the visualization of LF is emphasized by their legibility, selectivity, sensitivity and temporal photostability. In this study, development mechanisms have been proposed and the overall concept constitute a novel approach for vis‐à‐vis forensic investigations to trace an individual's identity. [ABSTRACT FROM AUTHOR]

This article describes the design and synthesis of a new series of hydrogel membranes composed of trialkyne derivatives of glycerol ethoxylate and bisphenol A diazide (BA‐diazide) or diazide‐terminated PEG600 monomer via a Cu(I)‐catalyzed photoclick reaction. The water‐swollen hydrogel membranes display thermoresponsive actuation and their lower critical solution temperature (LCST) values are determined by differential scanning calorimetry. Glycerol ethoxylate moiety serves as the thermoresponsive component and hydrophilic part, while the azide‐based component acts as the hydrophobic comonomer and most likely provides a critical hydrophobic/hydrophilic balance contributing also to the significant mechanical strength of the membranes. These hydrogels exhibit a reversible shape‐memory effect in response to temperature through a defined phase transition. The swelling and deswelling behavior of the membranes are systematically examined. Due to the click nature of the reaction, easy availability of azide and alkyne functional‐monomers, and the polymer architecture, the glass transition temperature (Tg) is easily controlled through monomer design and crosslink density by varying the feed ratio of different monomers. The mechanical properties of the membranes are studied by universal tensile testing measurements. Moreover, the hydrogels show the ability to absorb a dye and release it in a controlled manner by applying heat below and above the LCST. [ABSTRACT FROM AUTHOR]

Cu(I)-catalyzed azide-alkyne cycloaddition is shown here to be an efficient method to create adhesive materials in situ between glass and copper surfaces. Twelve formulations show adhesive strengths greater than a commercial product under comparable conditions, with the best combination of monomers the same as that previously developed for copper-copper adhesion. Strong adhesion is also achieved under water, an environment in which the commercial glue fails. Brass, iron, and stainless steel could also be adhered to glass using different formulations, but aluminum could not. The concentration and molar ratio of monomers, curing temperature, prefunctionalization of the glass surface, and the incorporation of flexibility-inducing components all have significant effects on adhesive performance. [ABSTRACT FROM AUTHOR]

The transition from the early applications of click chemistry in organic synthesis and biotechnology to materials synthesis was profoundly marked by the pioneering preparation of metal-adhesive polymers based on the copper (I)-catalyzed cycloaddition reaction between azides and alkynes. Herein, it is summarized a fascinating journey from the original discovery, made more than a decade ago, until the recent development of high-strength electrically conductive adhesives. [ABSTRACT FROM AUTHOR]

Electrically conductive adhesive polymers offer many potential advantages relative to SnPb solders, including reduced toxicity, low cost, low processing temperatures, and the ability to make application-specific formulations. Polymers generated from the copper(I)-catalyzed cycloaddition (CuAAC) reaction between multivalent azides and alkynes have previously been identified as strong metal-binding adhesives. Herein we demonstrate that the performance of these materials can be remarkably improved by the incorporation of a flexibility-inducing difunctionalized component and a tertiary amine additive in optimized concentrations. The best formulations were identified by means of rapid adhesion testing of a library of potential candidates by using a custom-built instrument and validated in an American Society for Testing and Materials (ASTM)-standard lap-shear test. Characteristic phase transitions were identified by differential scanning calorimetry (DSC) for adhesives with and without the additives as a function of curing temperature. The incorporation of flexible components was found to more than double the strength of the adhesive. Moreover, the adhesive was made electrically conductive by the inclusion of 20 wt % silver-coated copper flakes and further improved in this regard by the incorporation of multiwalled carbon nanotubes in the formulation. [ABSTRACT FROM AUTHOR]

A practical synthesis of N-cyclohexyl-11-(octylthio)undecanamide by thiol-ene click coupling reaction under UV light irradiation is reported. The title compound was characterized by elemental analysis, FT-IR, ¹H NMR, 13C NMR and MS spectroscopic methods. This molecule was found to be an efficient gelator for fluid oils, and the main physical parameters of the formed gels were also examined. [ABSTRACT FROM AUTHOR]

Abstract: [1,2,3]-Triazole-based polymers made by means of the copper(I)-catalyzed azide-alkyne [3+2] cycloaddition (CuAAC) exhibit selective gelling ability for DMSO and organic solvent mixtures containing at least 80% DMSO by volume. The organogels were characterized by FT-IR, DSC, TEM, and rheology. [Copyright &y& Elsevier]

Abstract: Thermal properties of polymers made from the copper(I)-catalyzed cycloaddition reaction between azides and alkynes have been investigated. Differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) were used to measure the glass transition temperatures (T g) of these materials. The polymers were found to have unusually high T g values, up to 60°C higher than the curing temperature. It has been shown that the increase of T g was time dependant, thus, depending on the state of cure of the material. [Copyright &y& Elsevier]

Hydrogel Actuators: Thermoresponsive Shape-Memory Hydrogel Actuators Made by Phototriggered Click Chemistry (Adv. Funct. Keywords: hydrogels; membranes; photoclick; polymers; shape-memory; thermoresponsive EN hydrogels membranes photoclick polymers shape-memory thermoresponsive 1 1 1 06/13/20 20200615 NES 200615 In article number 2001683, David Díaz Díaz and co-workers present a series of strong hydrogel membranes prepared via Cu(I)-catalyzed photo-click polymerization using a glycerol ethoxylate core. Hydrogels, membranes, photoclick, polymers, shape-memory, thermoresponsive. [Extracted from the article]

The largely demand in continued security issues makes necessary the development of novel materials with outstanding properties to improve the current detection techniques. In this context, latent fingerprint (LF) by fluorescent labeled materials (FLM) is one of the most attractive personnel identification methodologies. Here, two FLM based on polyhedral oligomeric silsesquioxane (POSS) nanohybrids labeled with dansyl chromophores have been synthesized and fully characterized. Their photophysical properties have confirmed that these materials clearly possess the prime qualifications as suitable LF sensing platforms. In fact, they adequately detect LFs on glassy surface with excellence legibility. Image 1 • Development of novel materials is warranted to improve detection techniques for security issues. • Latent fingerprint by fluorescent labeled materials is one of the most attractive personnel identification methodology. • Two new nanohybrids based on labelled octa-dansyl polyhedral oligomeric silsesquioxane have been prepared. • These materials possess the prime qualifications as suitable latent fingerprint sensing platforms. [ABSTRACT FROM AUTHOR]