Publications by authors named "Giao T M Nguyen"

Liquid crystal elastomers (LCEs) with promising applications in the field of actuators and soft robotics are reported. However, most of them are activated by external heating or light illumination. The examples of electroactive LCEs are still limited; moreover, they are monofunctional with one type of deformation (bending or contraction).

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The growing demand for flexible, stretchable, and wearable devices has boosted the development of ionogels used as polymer electrolytes. Developing healable ionogels based on vitrimer chemistry is a promising approach to improve their lifetimes as these materials are usually subjected to repeated deformation during functioning and are susceptible to damage. In this work, we reported in the first place the preparation of polythioether vitrimer networks based on the not extensively studied associative -transalkylation exchange reaction using thiol-ene Michael addition.

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The growing demand for all-solid flexible, stretchable, and wearable devices has boosted the need for liquid-free and stretchable ionoelastomers. These ionic conducting materials are subjected to repeated deformations during functioning, making them susceptible to damage. Thus, imparting cross-linked materials with healing ability seems particularly promising to improve their durability.

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Ionogels are solid polymer gel networks loaded with ionic liquid (IL) percolating throughout each other, giving rise to ionically conducting solid electrolytes. They combine the mechanical properties of polymer networks with the ionic conductivity, non-volatility, and non-flammability of ILs. In the frame of their applications in electrochemical-based flexible electronics, ionogels are usually subjected to repeated deformation, making them susceptible to damage.

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The human somatosensory network relies on ionic currents to sense, transmit, and process tactile information. We investigate hydrogels that similarly transduce pressure into ionic currents, forming a piezoionic skin. As in rapid- and slow-adapting mechanoreceptors, piezoionic currents can vary widely in duration, from milliseconds to hundreds of seconds.

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Nowadays, thermal regulation of the indoor environment is mandatory to reduce greenhouse gas emissions. The incorporation of Phase Change Materials (PCMs) and especially solid-solid PCMs (s/s PCMs) into building materials can be a major step forward in reducing energy consumption. Such materials are used for their high latent heat to save and release heat during phase change.

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Electroactive polymers based on dielectric elastomers are stretchable and compressible capacitors that can act as transducers between electrical and mechanical energies. Depending on the targeted application, soft actuators, sensors or mechanical-energy harvesters can be developed. Compared with conventional technologies, they present a promising combination of properties such as being soft, silent, light and miniaturizable.

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An ionic conducting membrane is an essential part in various electrochemical devices including ionic actuators. To miniaturize these devices, micropatterns of ionic conducting membrane are desired. Here, we present a novel type of ionogel that can be patterned using standard photolithography and soft imprinting lithography.

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Ionic actuators have attracted attention due to their remarkably large strain under low-voltage stimulation. Because actuation performance is mainly dominated by the electrochemical and electromechanical processes of the electrode layer, the electrode material and structure are crucial. Here, we report a graphitic carbon nitride nanosheet electrode-based ionic actuator that displays high electrochemical activity and electromechanical conversion abilities, including large specific capacitance (259.

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Electroactive, elastomeric, microfiber mats that show controllable pore size variation upon electrochemical stimulation are produced from semi-interpenetrating polymer networks (s-IPNs). This type of porous, elastomeric scaffolds that are mechanically dynamic under electrochemical stimuli could find new applications in stretchable electronics, (bio)filtration, soft robotics and stimulation of biological cells. These microfiber mats are prepared in two simple steps.

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The formation of associative networks in semidilute aqueous solutions of hydrophobically modified alginate (HM-alginate) is dependent on intermolecular hydrophobic interactions. Addition of beta-cyclodextrin (beta-CD) monomers to the system provides decoupling of these associations via inclusion complex formation with the polymer hydrophobic tails. This results in a dramatic decrease in the viscoelastic response of the system and a more extended local structure of the polymer chains, as shown by small-angle neutron scattering (SANS) measurements.

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Novel information about the effects of beta-cyclodextrin (beta-CD) addition and temperature on structural and rheological features of semidilute solutions of alginate and its hydrophobically modified analogue (HM-alginate) is given. Enhanced turbidity is observed for the HM-alginate solutions at high levels of beta-CD addition and low temperatures. The viscosity results revealed cross-linking of the alginate chains at high beta-CD concentrations and low temperatures.

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