Ryan Guterman

Anion-Exchange Reactions on a Robust Phosphonium Photopolymer for the Controlled Deposition of Ionic Gold Nanoclusters

UV curing (photopolymerization) is ubiquitous in many facets of industry ranging from the application of paints, pigments, and barrier coatings all the way to fiber optic cable production. To date no reports have focused on polymerizable phosphonium salts under UV irradiation, and despite this dearth of examples, they potentially offer numerous substantial advantages to traditional UV formulation components. We have generated a highly novel coating based on UV-curable trialkylacryloylphosphonium salts that allow for the fast (seconds) and straightforward preparation of ion-exchange surfaces amenable to a roll-to-roll process. We have quantified the surface charges and exploited their accessibility by employing these surfaces in an anion exchange experiment by which [Au25L18](-) (L = SCH2CH2Ph) nanocrystals can be assembled into the solid state. This unprecedented application of such surfaces offers a paradigm shift in the emerging chemistry of Au25 research where the nanocrystals remain single and intact and where the integrity of the cluster and its solution photophysical properties are resilient in the solid state. The specific loading of [Au25L18](-) on the substrates has been determined and the completely reversible loading and unloading of intact nanocrystals to and from the surface has been established. In the solid state, the assembly has an incredible mechanical resiliency, where the surface remains undamaged even when subjected to repeated Scotch tests.

Flexible and Actuating Nanoporous Poly(Ionic Liquid)–Paper-Based Hybrid Membranes

Porous and flexible actuating materials are important for the development of smart systems. We report here a facile method to prepare scalable, flexible actuating porous membranes based on a poly(ionic liquid)-modified tissue paper. The targeted membrane property profile was based on synergy of the gradient porous structure of a poly(ionic liquid) network and flexibility of a tissue paper. The gradient porous structure was built through an ammonia-triggered electrostatic complexation of a poly(ionic liquid) with poly(acrylic acid), which were previously impregnated inside the tissue paper. As a result, these porous membranes undergo deformation by bending in response to organic solvents in the vapor or liquid phase and can recover their shape in air, which demonstrates their ability to serve as solvent sensors. Besides, they show enhanced mechanical properties due to the introduction of mechanically flexible tissue paper that allows the membranes to be designed as new responsive textiles and contractile actuators.

Harnessing Poly(ionic liquid)s for Sensing Applications

The interest in poly(ionic liquid)s for sensing applications is derived from their strong interactions to a variety of analytes. By combining the desirable mechanical properties of polymers with the physical and chemical properties of ILs, new materials can be created. The tunable nature of both ionic liquids and polymers allows for incredible diversity, which is exemplified in their broad applicability. In this article we examine the new field of poly(ionic liquid) sensors by providing a detailed look at the current state-of-the-art sensing devices for solvents, gases, biomolecules, pH, and anions.

Kinetically Controlled Patterning of Highly Cross-Linked Phosphonium Photopolymers Using Simple Anion Exchange

A phosphonium salt possessing three methacrylate groups has been incorporated into a photopolymeric system to generate highly cross-linked polyelectrolyte networks. Emergent chemical and physical properties in the polymers were observed and attributed to the tandem increase in cross-link density and ion-content upon incorporation of the self-cross-linking cation. Anion-exchange with bis(trifluoromethylsulfonyl)imide or dodecylbenzenesulfonate resulted in significant differences in wettability and ion-exchange behavior. The passivating effects of dodecylbenzenesulfonate were utilized to selectively pattern fluorescein dye into the polymer network, highlighting a new patterning procedure using ionic-bond forming reactions.

Molecular Dynamics and Charge Transport in Highly Conductive Polymeric Ionic Liquids

Glassy dynamics and charge transport are studied for the polymeric ionic liquid (PIL) poly[tris(2-(2-methoxyethoxy)ethyl)ammonium acryloxypropyl sulfonate] (PAAPS) with varying molecular weight (9700, 44200, 51600, and 99500 g/mol) by broadband dielectric spectroscopy (BDS) in a wide frequency (10–2–107 Hz) and temperature range (100–400 K) and by DSC- and AC-chip calorimetry. The dielectric spectra are characterized by a superposition of (i) relaxation processes, (ii) charge transport, and (iii) electrode polarization. The relaxation processes (i) are assigned to the dynamic glass transition and a secondary relaxation. Charge transport (ii) can be described by the random free-energy barrier model as worked out by Dyre et al.; the Barton–Namikawa–Nakajima (BNN) relationship is well fulfilled over more than 8 decades. Electrode polarization (iii) follows the characteristics as analyzed by Serghei et al., with deviations on the low frequency side. The proportionality between the relaxation rate of the dynam...

Poly(ionic liquid) Binders as Ion conductors and Polymer Electrolyte Interface for Enhanced Electrochemical Performance of Water Splitting Electrodes

A poly(ionic liquid) (PIL) was used as a binder for NiCo oxide nanopowder in a water electrolysis standard assay to explore the role of polymers in a model electrocatalytic device. The comparison to technical standard binders such as Nafion™ or Fumion™ ionomers showed that the PIL improves the cycling stability under accelerated ageing conditions as well as the activity.

Porous polycarbene-bearing membrane actuator for ultrasensitive weak-acid detection and real-time chemical reaction monitoring

Soft actuators with integration of ultrasensitivity and capability of simultaneous interaction with multiple stimuli through an entire event ask for a high level of structure complexity, adaptability, and/or multi-responsiveness, which is a great challenge. Here, we develop a porous polycarbene-bearing membrane actuator built up from ionic complexation between a poly(ionic liquid) and trimesic acid (TA). The actuator features two concurrent structure gradients, i.e., an electrostatic complexation (EC) degree and a density distribution of a carbene-NH3 adduct (CNA) along the membrane cross-section. The membrane actuator performs the highest sensitivity among the state-of-the-art soft proton actuators toward acetic acid at 10−6 mol L−1 (M) level in aqueous media. Through competing actuation of the two gradients, it is capable of monitoring an entire process of proton-involved chemical reactions that comprise multiple stimuli and operational steps. The present achievement constitutes a significant step toward real-life application of soft actuators in chemical sensing and reaction technology.The design of soft actuators which show high sensitivity and allow for simultaneous interaction with multiple stimuli still remains a challenge. Here the authors demonstrate a highly sensitive proton actuator which allows monitoring of an entire process of chemical reactions that comprise multiple stimuli and operational steps.