scholarly journals Tissue-like skin-device interface for wearable bioelectronics by using ultrasoft, mass-permeable, and low-impedance hydrogels

2021 ◽  
Vol 7 (19) ◽  
pp. eabd3716
Author(s):  
Chanhyuk Lim ◽  
Yongseok Joseph Hong ◽  
Jaebong Jung ◽  
Yoonsoo Shin ◽  
Sung-Hyuk Sunwoo ◽  
...  
Keyword(s):  
Human Skin ◽  
Polymer Network ◽  
Wearable Devices ◽  
Liquid Electrolyte ◽  
Polymer Chains ◽  
Porous Polymer ◽  
High Mass ◽  
Water Molecules ◽  
Present Material ◽  
Target Molecules

Hydrogels consist of a cross-linked porous polymer network and water molecules occupying the interspace between the polymer chains. Therefore, hydrogels are soft and moisturized, with mechanical structures and physical properties similar to those of human tissue. Such hydrogels have a potential to turn the microscale gap between wearable devices and human skin into a tissue-like space. Here, we present material and device strategies to form a tissue-like, quasi-solid interface between wearable bioelectronics and human skin. The key material is an ultrathin type of functionalized hydrogel that shows unusual features of high mass-permeability and low impedance. The functionalized hydrogel acted as a liquid electrolyte on the skin and formed an extremely conformal and low-impedance interface for wearable electrochemical biosensors and electrical stimulators. Furthermore, its porous structure and ultrathin thickness facilitated the efficient transport of target molecules through the interface. Therefore, this functionalized hydrogel can maximize the performance of various wearable bioelectronics.

Enhanced Ion Transport in an Ether Aided Super Concentrated Ionic Liquid Electrolyte for Long-Life Practical Lithium Metal Battery Applications

2020 ◽  
Author(s):  
Urbi Pal ◽  
Fangfang Chen ◽  
Derick Gyabang ◽  
Thushan Pathirana ◽  
Binayak Roy ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Ion Transport ◽  
Current Density ◽  
Coulombic Efficiency ◽  
High Energy ◽  
Liquid Electrolyte ◽  
High Mass ◽  
Lithium Metal ◽  
Ionic Liquid Electrolyte ◽  
Lithium Metal Battery

We explore a novel ether aided superconcentrated ionic liquid electrolyte; a combination of ionic liquid, <i>N</i>-propyl-<i>N</i>-methylpyrrolidinium bis(fluorosulfonyl)imide (C<sub>3</sub>mpyrFSI) and ether solvent, <i>1,2</i> dimethoxy ethane (DME) with 3.2 mol/kg LiFSI salt, which offers an alternative ion-transport mechanism and improves the overall fluidity of the electrolyte. The molecular dynamics (MD) study reveals that the coordination environment of lithium in the ether aided ionic liquid system offers a coexistence of both the ether DME and FSI anion simultaneously and the absence of ‘free’, uncoordinated DME solvent. These structures lead to very fast kinetics and improved current density for lithium deposition-dissolution processes. Hence the electrolyte is used in a lithium metal battery against a high mass loading (~12 mg/cm<sup>2</sup>) LFP cathode which was cycled at a relatively high current rate of 1mA/cm<sup>2</sup> for 350 cycles without capacity fading and offered an overall coulombic efficiency of >99.8 %. Additionally, the rate performance demonstrated that this electrolyte is capable of passing current density as high as 7mA/cm<sup>2</sup> without any electrolytic decomposition and offers a superior capacity retention. We have also demonstrated an ‘anode free’ LFP-Cu cell which was cycled over 50 cycles and achieved an average coulombic efficiency of 98.74%. The coordination chemistry and (electro)chemical understanding as well as the excellent cycling stability collectively leads toward a breakthrough in realizing the practical applicability of this ether aided ionic liquid electrolytes in lithium metal battery applications, while delivering high energy density in a prototype cell.

Syntheses and crystal structures of two magnesium–tetrazole compounds in salt and polymeric forms

2015 ◽  
Vol 71 (3) ◽  
pp. 222-228 ◽  
Author(s):  
Mohamed Abdellatif Bensegueni ◽  
Aouatef Cherouana ◽  
Slimane Dahaoui
Keyword(s):  
Alkaline Earth ◽  
Three Dimensional ◽  
Polymer Chains ◽  
Magnesium Ion ◽  
Water Molecules ◽  
Compound I ◽  
Hydrothermal Conditions ◽  
One Dimensional ◽  
Polymeric Chains ◽  
Hydrogen Bonded

Two alkaline earth–tetrazole compounds, namelycatena-poly[[[triaquamagnesium(II)]-μ-5,5′-(azanediyl)ditetrazolato-κ3N1,N1′:N5] hemi{bis[μ-5,5′-(azanediyl)ditetrazolato-κ3N1,N1′:N2]bis[triaquamagnesium(II)]} monohydrate], {[Mg(C2HN9)(H2O)3][Mg2(C2HN9)2(H2O)6]0.5·H2O}n, (I), and bis[5-(pyrazin-2-yl)tetrazolate] hexaaquamagnesium(II), (C5H3N6)[Mg(H2O)6], (II), have been prepared under hydrothermal conditions. Compound (I) is a mixed dimer–polymer based on magnesium ion centres and can be regarded as the first example of a magnesium–tetrazolate polymer in the crystalline form. The structure shows a complex three-dimensional hydrogen-bonded network that involves magnesium–tetrazolate dimers, solvent water molecules and one-dimensional magnesium–tetrazolate polymeric chains. The intrinsic cohesion in the polymer chains is ensured by N—H...N hydrogen bonds, which formR22(7) rings, thus reinforcing the propagation of the polymer chain along theaaxis. The crystal structure of magnesium tetrazole salt (II) reveals a mixed ribbon of hydrogen-bonded rings, of typesR22(7),R22(9) andR24(10), running along thecaxis, which are linked byR24(16) rings, generating a 4,8-cflunet.

One-dimensional CuIIcoordination polymers containingC2h-symmetric 1,1′:4′,1′′-terphenyl-3,3′-dicarboxylate linkers

2015 ◽  
Vol 71 (10) ◽  
pp. 929-935 ◽  
Author(s):  
Hyun-Chul Kim ◽  
Ja-Min Gu ◽  
Seong Huh ◽  
Chul-Hyun Yo ◽  
Youngmee Kim
Keyword(s):  
Coordination Polymers ◽  
Three Dimensional ◽  
Polymer Chains ◽  
Water Molecules ◽  
Binding Modes ◽  
Bridging Ligands ◽  
One Dimensional ◽  
X Ray Crystallography ◽  
Dimensional Network ◽  
The One

Two new one-dimensional CuIIcoordination polymers (CPs) containing theC2h-symmetric terphenyl-based dicarboxylate linker 1,1′:4′,1′′-terphenyl-3,3′-dicarboxylate (3,3′-TPDC), namelycatena-poly[[bis(dimethylamine-κN)copper(II)]-μ-1,1′:4′,1′′-terphenyl-3,3′-dicarboxylato-κ4O,O′:O′′:O′′′] monohydrate], {[Cu(C20H12O4)(C2H7N)2]·H2O}n, (I), andcatena-poly[[aquabis(dimethylamine-κN)copper(II)]-μ-1,1′:4′,1′′-terphenyl-3,3′-dicarboxylato-κ2O3:O3′] monohydrate], {[Cu(C20H12O4)(C2H7N)2(H2O)]·H2O}n, (II), were both obtained from two different methods of preparation: one reaction was performed in the presence of 1,4-diazabicyclo[2.2.2]octane (DABCO) as a potential pillar ligand and the other was carried out in the absence of the DABCO pillar. Both reactions afforded crystals of different colours,i.e.violet plates for (I) and blue needles for (II), both of which were analysed by X-ray crystallography. The 3,3′-TPDC bridging ligands coordinate the CuIIions in asymmetric chelating modes in (I) and in monodenate binding modes in (II), forming one-dimensional chains in each case. Both coordination polymers contain two coordinated dimethylamine ligands in mutuallytranspositions, and there is an additional aqua ligand in (II). The solvent water molecules are involved in hydrogen bonds between the one-dimensional coordination polymer chains, forming a two-dimensional network in (I) and a three-dimensional network in (II).

scholarly journals Polymer gel with a flexible and highly ordered three-dimensional network synthesized via bond percolation

2019 ◽  
Vol 5 (12) ◽  
pp. eaax8647 ◽  
Author(s):  
X. Li ◽  
S. Nakagawa ◽  
Y. Tsuji ◽  
N. Watanabe ◽  
M. Shibayama
Keyword(s):  
Network Formation ◽  
General Scheme ◽  
Polymer Network ◽  
Three Dimensional ◽  
Geometric Constraints ◽  
Polymer Chains ◽  
Bond Percolation ◽  
Polymer Gel ◽  
Temporal Correlations ◽  
Before And After

Gels are a soft elastic material consisting of a three-dimensional polymer network with nanometer-sized pores and are used in a variety of applications. However, gel networks typically have a substantial level of defects because the network formation reaction proceeds stochastically. In this study, we present a general scheme to fabricate gels with extremely low levels of defects by applying geometric constraints into pregel solution based on the “bond percolation” concept. In the formed gel, stationary laser speckles, which are an indicator of spatial defects, were not observed at all. In addition, we found that the concentration fluctuations of the polymer chains were ergodic across the whole gel network. In such a homogeneous gel, both the spatial and temporal correlations of polymer chains are the same before and after gelation.

Pseudoelasticity and Nonideal Mullins Effect of Nanocomposite Hydrogels

2016 ◽  
Vol 83 (11) ◽  
Author(s):  
Jingda Tang ◽  
Xing Chen ◽  
Yongmao Pei ◽  
Daining Fang
Keyword(s):  
Polymer Network ◽  
Residual Deformation ◽  
Polymer Chains ◽  
Residual Fraction ◽  
Mullins Effect ◽  
Nanocomposite Hydrogels ◽  
High Toughness ◽  
Physically Crosslinked ◽  
Two Parameters ◽  
The Ideal

The polymer network of a nanocomposite (NC) hydrogel is physically crosslinked by nanoclay. Recently reported high toughness of nanocomposite (NC) hydrogels highlights the importance of their dissipative properties. The desorption of polymer chains from clay surface may contribute mostly to the hysteresis of NC hydrogels. Here, we proposed a mechanistically motivated pseudoelastic model capable of characterizing the hysteresis of NC hydrogels. The two parameters in the proposed damage variable can be determined by the experiments. We applied the model to the uniaxial tension and reproduced the ideal Mullins effect of NC hydrogels. Furthermore, we considered two nonideal effects: residual deformation and nonideal reloading in multicycle test, using newly proposed damage parameters. A power law with the order of 1/3 is established between the residual fraction of the stretch and the re-adsorption ratio of polymer chains. Finally, we demonstrated the dissipative properties of various NC hydrogels with the model.

scholarly journals Atomic Hydrogen Surrounded by Water Molecules, H(H2O)m, Modulates Basal and UV-Induced Gene Expressions in Human Skin In Vivo

PLoS ONE ◽  
2013 ◽  
Vol 8 (4) ◽  
pp. e61696 ◽  
Author(s):  
Mi Hee Shin ◽  
Raeeun Park ◽  
Hideo Nojima ◽  
Hyung-Chel Kim ◽  
Yeon Kyung Kim ◽  
...  
Keyword(s):  
Human Skin ◽  
Atomic Hydrogen ◽  
Water Molecules ◽  
Gene Expressions

Introduction of an ordered porous polymer network into a ceramic alumina membrane via non-hydrolytic sol–gel methodology for targeted dynamic separation

RSC Advances ◽  
2014 ◽  
Vol 4 (73) ◽  
pp. 38630-38642 ◽  
Author(s):  
Minjia Meng ◽  
Yan Liu ◽  
Min Zhang ◽  
Yonghai Feng ◽  
Yongsheng Yan
Keyword(s):  
Sol Gel ◽  
Polymer Network ◽  
Porous Polymer ◽  
Alumina Membrane ◽  
Gentisic Acid ◽  
Gel Method ◽  
Sol Gel Method ◽  
Ordered Porous

Highly selective composite imprinted alumina membrane (CIAM) for gentisic acid (GA) was successfully prepared via non-hydrolytic sol–gel method to target separation.

Conformation of Free Linear Polymer Chains in a Polymer Network

1997 ◽  
Vol 30 (16) ◽  
pp. 4704-4712 ◽  
Author(s):  
Xiaodu Liu ◽  
Barry J. Bauer ◽  
Robert M. Briber
Keyword(s):  
Polymer Network ◽  
Polymer Chains ◽  
Linear Polymer

Zigzag polymer chains incatena-poly[[[triaqua(isobutyrato-κO)magnesium(II)]-μ-isobutyrato-κ2O:O′] monohydrate]

2013 ◽  
Vol 69 (10) ◽  
pp. 1144-1146 ◽  
Author(s):  
Iurie L. Malaestean ◽  
Sebastian Schmitz ◽  
Arkady Ellern ◽  
Paul Kögerler
Keyword(s):  
Crystal Structure ◽  
Polymer Chains ◽  
The Other ◽  
Water Molecules ◽  
Formula Unit ◽  
One Dimensional ◽  
Solvent Water ◽  
Water Ligands ◽  
Van Der Waals Contacts ◽  
Hydrophobic Areas

The structure of the title compound, {[Mg(C4H7O2)2(H2O)3]·H2O}n, features one-dimensional ...(μ2-ib)Mg(μ2-ib)Mg... zigzag chains (ib is isobutyrate) parallel to thecaxis. The octahedral Mg environment is completed by threefac-oriented terminal water ligands, as well as one further monodentate end-on coordinated ib ligand. In the crystal structure, the hydrophobic ib groups are all oriented within one half of the coordination perimeter of each chain, whereas the water ligands, together with hydrogen-bonded noncoordinated solvent water molecules, define the other half. Along theaaxis, neighbouring strands are oriented so that both the hydrophilic and hydrophobic sides are adjacent to each other. This results in an extensive hydrogen-bonding network within the hydrophilic areas, also involving an additional solvent water molecule per formula unit. There are van der Waals contacts between the aliphatic isopropyl groups of the hydrophobic areas.

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