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Sodium metal batteries have been emerging as promising candidates for post-Li battery systems owing to the natural abundance, low costs, and high energy density of Na metal. However, exploiting an Na metal anode is accompanied by uncontrolled Na electrodeposition, particularly concerning dendrite growth, hampering practical Na metal battery applications. Herein, we propose sodiophilic gel polymer electrolytes with a porosity-gradient Janus structure to alleviate Na dendrite growth. Tethering only 1.1 mol % sodiophilic poly(ethylene glycol) to poly(vinylidene fluoride

The aim of this research was to examine the effects of travel expenditures on life satisfaction in the context of the COVID-19 pandemic. For the research, a curvilinear relationship was established between life satisfaction and travel expenditures that was then compared between 2018 and 2020. The study subjects were middle-aged and older adults who completed the 2018 and 2020 waves of the Korean Longitudinal Study of Aging. Demographic, travel expenditure, and life satisfaction data were collected, and quadratic regression analysis was conducted to examine the effects of travel expenditures on life satisfaction before and during the COVID-19 pandemic. The first-order condition was computed to determine the optimal level of travel expenditures to maximize life satisfaction, and the results exhibit that the utility of travel expenditure decreased during the COVID-19 pandemic.

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The purpose of this research is to explore the moderating effect of carrier type on the effects of upper echelon attributes. The study subject is the position of chief executive officer (CEO). The dependent variable is market-to-book value; the independent variables are CEO age, tenure, and educational background. The moderator is LCC. For the data collection, this study used COMPUSTAT and EXECUCOMP using the standard industry classification code 4512; the data are collected from Annual 10K and Linkedin. There are 15 airlines examined, and the study period is from 1999–2019; in total, 210 observations were used for the data analysis. Multiple regression analysis was the main instrument used to test the research hypotheses. The results indicate that both older CEOs in LCCs performed better in the market.

We describe the phase behavior of a partially charged ternary polymer blend model system, comprising a compositionally symmetric poly[(oligo(ethylene glycol) methyl ether methacrylate-co-oligo(ethy...

Pressure sensitive adhesives (PSAs) are widely used in a variety of applications (e.g., sticky note and packing tape). As for most commercial polymer products, current PSA materials are primarily d...

This study concerns the development of a well-defined synthetic route to obtain lignin-derived multifunctional graft polymers by simple chemical modification and atom-transfer radical polymerization. By grafting ion-conducting and cross-linkable moieties onto the lignin, star-shaped functional polymers are prepared. Upon cross-linking under ultraviolet light irradiation, the resulting polymer network exhibits mechanical stability even at high temperature, whereas the chain mobility is maintained despite the cross-linked structure. Their use as solid polymer electrolytes (SPEs) and binders for all-solid-state lithium metal batteries (LMBs) is also evaluated. The lignin-derived graft polymers provide a facile ion conduction pathway and also efficiently suppress lithium dendrite growth during cycling, thereby attaining excellent cycling performance for the LMB cell compared to that with a conventional liquid electrolyte-Celgard system.

We describe the formation of bicontinuous microemulsions (BμE) from a series of three model charged ternary polymer blends comprising an AB diblock copolymer and the constituent A and B homopolymers, where A is a partially charged poly[(oligo(ethylene glycol) methyl ether methacrylate-co-oligo(ethylene glycol) propyl sodium sulfonate methacrylate)] (POEGMA) block with systematically tuned ion concentration and B is a neutral polystyrene (PS) block. The mole fraction of charged groups in the POEGMA block and the corresponding POEGMA homopolymer was 7, 23, or 36%. The phase diagrams of ternary blends with variable ion concentrations have been mapped out along the volumetrically symmetric isopleth by using a combination of rheology, small-angle neutron and X-ray scattering, and cloud point measurements. A well-defined BμE channel is found over an unusually wide range of homopolymer compositions (2–7%), in the proximity of the Lifshitz multicritical point anticipated by mean-field theory. While the ion concentration significantly impacts both the morphological length scale and the extent of the BμE phase over a wide range of compositions and temperatures, it is remarkable that the BμE persists over a significant range of segregation strength. This study provides new insight into the rational design of charged ternary polymer blends to tune the structural characteristics of the BμE by modulating ion concentration.

Metal batteries have been emerging as next-generation battery systems by virtue of ultrahigh theoretical specific capacities and low reduction potentials of metallic anodes. However, significant concerns regarding the uncontrolled metallic dendrite growth accompanied by safety hazards and short lifespan have impeded practical applications of metal batteries. Although a great deal of effort has been pursued to highlight the thermodynamic origin of dendrite growth and a variety of experimental methodologies for dendrite suppression, the roles of polymer materials in suppressing the dendrite growth have been underestimated. This review aims to give a state-of-the-art overview of contemporary dendrite-suppressing polymer materials from the electro-chemo-mechanical viewpoint of macromolecular design, including i) homogeneous distribution of metal ion flux, ii) mechanical blocking of metal dendrites, iii) tailoring polymer structures, and iv) modulating the physical configuration of polymer membranes. Judiciously tailoring electro-chemo-mechanical properties of polymer materials provides virtually unlimited opportunities to afford safe and high-performance metal battery systems by resolving problematic dendrite issues. Transforming these rational design strategies into building dendrite-suppressing polymer materials and exploiting them towards polymer electrolytes, separators, and coating materials hold the key to realizing safe, dendrite-free, and long-lasting metal battery systems.

The main goal of this study was to investigate the association between corporate social responsibility (CSR) and the value of restaurant firms by employing triple bottom line theory, a framework for a business model of sustainable development focusing on profit, environment, and people rather than just maximizing profit. Even though triple bottom line has been a common theoretical foundation in the CSR area, there is sparse literature on the theory in the context of CSR in the restaurant domain. Data regarding CSR dimensions and market-to-book value from 32 publicly traded restaurant firms in the US stock market for the period 1999–2012 were gathered, and panel data analysis methods of ordinary least square, one-way fixed effect, and time series feasible generalized least square were employed. The results revealed that economic CSR enhanced restaurant value, whereas environmental CSR diminished the value. The theoretical contribution of this study is that it will broaden the scope of triple bottom line theory. The results of the study will help restaurant administrators determine CSR policy.

The purpose of this research is to examine the determinants of coffee shop purchase intention. The research domain is Starbucks, which is the brand ranked first in the coffee shop market. This study selects healthiness, hygiene, quarantine, ease of app use, and environmental responsibility as candidates for the antecedents of purchase intention. For hypothesis testing, this research used a survey and recruited survey participants using Amazon Mechanical Turk, and carried out multiple linear regressions to test research hypotheses. The number of valid observations for the data analysis is 474. It was found that purchase intention is positively influenced by healthiness, hygiene, quarantine, and ease of app use. However, environmental responsibility was identified as a nonsignificant attribute to account for purchase intention. Practical implications are presented for coffee shop management. The outcomes contribute to the literature by scrutinizing café customers’ purchase intention with various attributes.

Graphene oxide (GO) is considered a comparatively recent biomaterial with enormous potential because of its nontoxicity, high dispersity, and enhanced interaction with biomolecules. These characteristics of GO can promote the interactions between the substrates and cell surfaces. In this study, we incorporated GO in a cryogel-based scaffold system to observe their influence on the osteogenic responses of human tonsil-derived mesenchymal stem cells (hTMSCs). Compared to polyethylene glycol (PEG)-based cryogel scaffold, GO-embedded PEG-based (PEGDA-GO) cryogels not only showed improved cell attachment and focal adhesion kinase (FAK) signaling activation but also enhanced cell viability. Taken together, we demonstrated that PEGDA-GO cryogels can stimulate osteogenic differentiation under an osteoinductive condition and enhance osteogenic phenotypes compared to the control group. In summary, we demonstrate that GO embedded in cryogels system is an effective biofunctionalizing scaffold to control osteogenic commitment of stem cells.

Novel “turn off-on” optosensors based on amphiphilic thiophene copolymers coated CdTe quantum dots (P1QDs and P2QDs) were developed for the dual detection of heparin and spermine. The emission of the P1QDs and P2QDs is found to be quenched in the presence of heparin by electron transfer mechanism through electrostatic and hydrogen bonding interactions. Upon the addition of spermine, heparin has been removed from the surface of P1QDs and P2QDs due to the strong electrostatic interactions between spermine and heparin, which showed significant fluorescence recovery of the sensors. Under optimum conditions, both P1QDs and P2QDs sensors displayed excellent limits of detection for heparin of 1.59 nmol L −1 (R 2 = 0.9955) and 0.88 nmol L −1 (R 2 = 0.9908) with linear ranges of 1–11 μmol L −1 and 1–10 μmol L −1 , respectively. P1QDs and P2QDs also showed remarkable limits of detection for spermine of 2.90 nmol L −1 (R 2 = 0.9957) and 1.66 nmol L −1 (R 2 = 0.9928) with linear ranges of 0.05–15 μmol L −1 and 1–12 μmol L −1 , respectively. The P1QDs and P2QDs sensors show a high selectivity to heparin and spermine over common interfering substances and ions. In addition, the proposed method was successfully utilized in serum samples, which could facilitate the further heparin and spermine biochemical and biomedical research.

The purpose of this study is to examine the monetary policy transmission mechanisms in seven South Asian Association for Regional Cooperation (SAARC) countries to discover the viability of the convergence of the SAARC into a monetary and economic union based on common monetary channels. By employing optimal currency area theory, we used the restricted VAR analysis on the annual data from 1978 to 2017. We find that the money channel response provides proof for the presence of an exchange rate and credit channels. Furthermore, the real sector also responds to changes in fiscal and monetary shocks through the exchange rate and credit channels over short-run to long-run time horizons. This implies that the SAARC is a good candidate due to common exchange rate and credit channels. The function of the variance decomposition and the impulse for forming a monetary and economic union is that they share a coincidental pattern of dynamic reactions of inflation and growth to exogenous shocks. If the SAARC monetary and economic union is created, it will reap overall economic benefits inside and outside of Asia just like the European Union (EU).

Solid polymer electrolytes (SPEs) based on polysiloxane having ion-conducting poly(ethylene oxide) (PEO) groups crosslinked with modified gallic acid from natural resources are prepared by thiol-ene click reaction for all-solid-state lithium metal battery applications. The effects of composition and crosslinking density on physical and electrochemical properties of the SPEs are systematically studied. The SPEs are found to be thermally and mechanically stable even at elevated temperature due to stable crosslinked polymer networks by modified gallic acid crosslinker. Furthermore, ionic conductivity of SPE based on 80 mol% of PEO group and 20 mol% of modified gallic acid crosslinker is found to be comparable to that of polymer electrolyte having a wax state. The formation and growth of lithium dendrites are effectively suppressed by the SPE due to its good compatibility with lithium metal anode and mechanical suppression effect. All-solid-state lithium metal battery is fabricated with SPE-integrated cathode and it is found that SPE exhibits superior cycle performance to conventional liquid electrolyte/separator system at 60 °C that is attributed to the good thermal stability and lithium dendrite-suppressing ability of the SPE.

Lithium-metal anode has fundamental problems concerning formation and growth of lithium dendrites, which prevents practical applications of next generation of high-capacity lithium-metal batteries. The synergistic combination of solid polymer electrolyte (SPE) crosslinked with naturally occurring terpenes and lithium-powder anode is promising solution to resolve the dendrite issues by substituting conventional liquid electrolyte/separator and lithium-foil anode system. A series of SPEs based on polysiloxane crosslinked with natural terpenes are prepared by facile thiol-ene click reaction under mild condition and the structural effect of terpene crosslinkers on electrochemical properties is studied. Lithium powder with large surface area is prepared by droplet emulsion technique (DET) and used as anode material. The effect of the physical state of electrolyte (solid/liquid) and morphology of lithium-metal anode (powder/foil) on dendrite growth behavior is systematically studied. The synergistic combination of SPE and lithium-powder anode suggests an effective solution to suppress the dendrite growth owing to the formation of a stable solid-electrolyte interface (SEI) layer and delocalized current density.

The multifunctional properties of 2D boron nitride nanoflakes (BNNFs) in gel polymer electrolytes (GPEs) are presented. A small addition (0.5 wt%) of BNNFs into the GPE substantially improves all the advantageous properties of the GPE including ionic conductivity, Li+ transference number, mechanical modulus, and dendrite-suppressing capability, thereby enabling high performance lithium metal batteries.

As interest in electric vehicles and mass energy storage systems continues to grow, Li-O

Na-ion batteries are attractive as an alternative to Li-ion batteries because of their lower cost. Organic compounds have been considered as promising electrode materials due to their environmental friendliness and molecular diversity. Herein, aluminum-coordinated poly(tetrahydroxybenzoquinone) (P(THBQ-Al)), one of the coordination polymers, is introduced for the first time as a promising cathode for Na-ion batteries. P(THBQ-Al) is synthesized through a facile coordination reaction between benzoquinonedihydroxydiolate (C6O6H22–) and Al3+ as ligands and complex metal ions, respectively. Tetrahydroxybenzoquinone is environmentally sustainable, because it can be obtained from natural resources such as orange peels. Benzoquinonedihydroxydiolate also contributes to delivering high reversible capacity, because each benzoquinonedihydroxydiolate unit is capable of two electron reactions through the sodiation of its conjugated carbonyl groups. Electrochemically inactive Al3+ improves the structural stability of P(...

Core-shell silica particles with ion-conducting poly(ethylene glycol) and anion-trapping boron moiety in the shell layer were prepared to be used as fillers for polymer composite electrolytes based on organic/inorganic hybrid branched copolymer as polymer matrix for all-solid-state lithium-ion battery applications. The core-shell silica particles were found to improve mechanical strength and thermal stability of the polymer matrix and poly(ethylene glycol) and boron moiety in the shell layer increase compatibility between filler and polymer matrix. Furthermore, boron moiety in the shell layer increases both ionic conductivity and lithium transference number of the polymer matrix because lithium salt can be more easily dissociated by the anion-trapping boron. Interfacial compatibility with lithium metal anode is also improved because well-dispersed silica particles serve as protective layer against interfacial side reactions. As a result, all-solid-state battery performance was found to be enhanced when the copolymer having core-shell silica particles with the boron moiety was used as solid polymer electrolyte.

Organic/inorganic hybrid semi-interpenetrating network (semi-IPN) polymer electrolytes (HIPEs) based on poly(ethylene oxide- co -ethylene carbonate) (PEOEC) have been developed for all-solid-state lithium battery applications. In comparison to those of poly(ethylene oxide) (PEO), salient features of the PEOEC are the amorphous nature and high dielectric constant, which provide enhanced ionic conductivity. The organic/inorganic hybrid network matrix in the HIPEs is composed of different contents of photo-cross-linked octa-functional POSS acrylate (OA-POSS) and ethoxylated trimethylolpropane triacrylate (ETPTA). The effect of OA-POSS on solid-state electrolyte properties of the HIPEs is investigated in terms of the dimensional stability, thermal behavior, and ionic conductivity. Due to the presence of the rigid and bulky POSS moiety, the HIPEs exhibit improvement in ionic conductivity along with enhanced dimensional stability. The high capacity and good cycle performance of lithium batteries with the HIPEs demonstrate feasibility of applying the HIPEs to solid-state electrolytes for all-solid-state lithium batteries that can operate at elevated temperatures.

Polyamide reverse osmosis (RO) membranes with carbon nanotubes (CNTs) are prepared by interfacial polymerization using trimesoyl chloride (TMC) solutions in n-hexane and aqueous solutions of m-phenylenediamine (MPD) containing functionalized CNTs. The functionalized CNTs are prepared by the reactions of pristine CNTs with acid mixture (sulfuric acid and nitric acid of 3:1 volume ratio) by varying amounts of acid, reaction temperature, and reaction time. CNTs prepared by an optimized reaction condition are found to be well-dispersed in the polyamide layer, which is confirmed from atomic force microscopy, scanning electron microscopy, and Raman spectroscopy studies. The polyamide RO membranes containing well-dispersed CNTs exhibit larger water flux values than polyamide membrane prepared without any CNTs, although the salt rejection values of these membranes are close. Furthermore, the durability and chemical resistance against NaCl solutions of the membranes containing CNTs are found to be improved compared with those of the membrane without CNTs. The high membrane performance (high water flux and salt rejection) and the improved stability of the polyamide membranes containing CNTs are ascribed to the hydrophobic nanochannels of CNTs and well-dispersed states in the polyamide layers formed through the interactions between CNTs and polyamide in the active layers.

A series of composite polymer electrolytes were prepared using an organic/inorganic hybrid branched-graft copolymer (BCP) based on poly(ethylene glycol) methyl ether methacrylate (PEGMA) and 3-(3,5,7,9,11,13,15-heptaisobutylpentacyclo-[9.5.1.13,9.15,15.17,13]octasiloxane-1-yl)propyl methacrylate (MA-POSS) as the polymer matrix and poly(ethylene glycol)-grafted graphene oxide (PGO) as the filler material, and they were applied as solid-state polymer electrolytes (SPEs) for lithium-ion battery applications. The ionic conductivity of the composite polymer electrolyte containing 0.2 wt% of PGO (2.1 × 10−4 S cm−1 at 30 °C) was found to be one order of magnitude higher than that of the BCP (1.1 × 10−5 S cm−1 at 30 °C); the pristine polymer matrix, because of the larger amount of lithium salt, can be dissociated in the composite polymer electrolyte by Lewis acid–base interactions between the PGO and lithium salt. The thermal and mechanical stabilities of the composite polymer electrolytes were also improved by introducing PGO fillers and reasonable storage modulus values were maintained even at elevated temperatures up to 150 °C. All-solid-state battery performance was evaluated with the composite polymer electrolyte containing 0.2 wt% of PGO, resulting in superior cycle performance compared to that of the BCP due to the enhanced ionic conductivity as well as additional ion-conducting paths provided by the PGO fillers.

A series of organic/inorganic hybrid branched (BCPs) and linear (LCPs)-graft copolymers comprising poly(ethylene glycol) methyl ether methacrylate (PEGMA), 3-(3,5,7,9,11,13,15-heptaisobutyl-pentacyclo[9.5.1.13,9.15,15.17,13]octasiloxane-1-yl)propyl methacrylate (MA-POSS), and ethylene glycol dimethacrylate (EGDMA) were synthesized via reversible addition–fragmentation chain transfer (RAFT) polymerization for application to solid polymer electrolyte (SPE) materials in high-temperature lithium-ion batteries. Dimensionally stable free-standing films were obtained when the MA-POSS contents in BCPs and LCPs are larger than 21 mol% and maintained their original shape and storage modulus even if the temperature increases up to 90 °C. The maximum ionic conductivity value of the BCP electrolyte containing 21 mol% of MA-POSS was 1.6 × 10−4 S cm−1 at 60 °C and that of the LCP electrolyte containing 21 mol% of MA-POSS was 5.6 × 10−5 S cm−1 at 60 °C, indicating that the branched-graft copolymer electrolyte has higher ionic conductivity than the linear-graft counterpart, due to the increased chain mobility, as estimated by a smaller Tg value. All-solid-state batteries prepared using the BCP electrolyte showed a reasonable cell performance at 60 °C without causing safety problems, demonstrating great potential of BCPs as SPE materials for high-temperature battery systems.

A series of composite electrolytes (CEs) consisting of organic/inorganic hybrid star-shaped polymer (SPP13), plasticizer (PEG-functionalized POSS derivatives), and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) were prepared to investigate the effects of the composite compositions and PEG chain length of PEs on the properties of CEs. SPP13 was prepared via ATRP from poly(ethylene glycol) methyl ether methacrylate (PEGMA) and methacryl-cyclohexyl-POSS (MA-POSS) using an octafunctional initiator, and the PEG-functionalized POSS derivatives were synthesized by the hydrosilylation reaction of octakis(dimethylsilyloxy)silsesquioxane (OHPS) and allyl-PEG. The CEs were found to be dimensionally-stable enough to separate the electrodes in batteries, but they still possessed high mobility of ion-conducting P(PEGMA) segments, as estimated by the low glass transition temperatures ( T g ). The CEs having solid-state show quite high ionic conductivity (4.5 × 10 −5 S cm −1 at 30 °C) which is about three times of magnitude larger than that of the matrix polymer (SPP13) electrolyte (1.5 × 10 −5 S cm −1 at 30 °C). The CEs were electrochemically stable up to +4.2 V without the decomposition of electrolytes. An all-solid-state lithium battery prepared from the CEs exhibited larger discharge capacity than that prepared from the SPP13 electrolyte at 60 °C.

Solid polymer electrolytes (SPEs) for all-solid-state lithium-ion batteries are prepared by simple one-pot polymerization induced by ultraviolet (UV) light using poly(ethylene glycol) methyl ether methacrylate (PEGMA) as an ion-conducting monomeric unit and tannic acid (TA)-based crosslinking agent and plasticizer. The crosslinking agent and plasticizer based on natural resources are obtained from the reaction of TA with glycidyl methacrylate and glycidyl poly(ethylene glycol), respectively. Dimensionally stable free-standing SPE having a large ionic conductivity of 5.6×10(-4) Scm(-1) at room temperature can be obtained by the polymerization of PEGMA into P(PEGMA) with a very small amount (0.1 wt %) of the crosslinking agent and 2.0 wt % of the plasticizer. The ionic conductivity value of SPE with a crosslinked structure is one order of magnitude larger than that of linear P(PEGMA) in the waxy state.

Solid polymer electrolytes based on poly(ethylene glycol) and cardanol, a renewable resource from cashew nut shell liquid, were prepared and their properties were investigated. UV-induced self-crosslinkable polymer matrix were synthesized by free radical copolymerization of poly(ethylene glycol) methyl ether methacrylate and 2-hydroxy-3-cardanylpropyl methacrylate. Solid polymer electrolytes were prepared by simple solution casting method followed by UV irradiation, which induces cross-linking reaction of cardanol moieties. The obtained electrolytes were dimensionally stable, free-standing, and thermally stable. Maximum ionic conductivities of 2.6 X 10-5 S/cm at 30 oC and 2.5 X 10-4 S/cm at 60 oC were obtained when cardanol content in the matrix polymer was 8 mol% and lithium salt doping concentration ([Li+]/[EO unit]) was 0.05. The feasibility of the prepared electrolytes to solid polymer electrolytes for lithium secondary batteries was examined by linear sweep voltammetry and galvanostatic charge-discharge cell test. Figure 1

Solid polymer electrolytes (SPEs) comprising crosslinking agent and plasticizer based on natural resources, tannic acid (TA), were prepared by facile one-pot ultraviolet (UV) light induced polymerization for all-solid-state lithium-ion battery applications. Poly(ethylene glycol) methyl ether methacrylate (PEGMA) as an ion-conducting unit and methacrylated TA (MTA) as a crosslinking agent are copolymerized in the presence of poly(ethylene glycol)-grafted TA (PTA) as a plasticizer. Dimensionally stable free-standing SPEs are obtained with the incorporation of very small amount, 0.1 wt%, of MTA compared to that of the PEGMA due to high crosslinking efficiency of the MTA. When 2.0 wt% of PTA with wax state having ion-conducting chain is added, maximum ionic conductivity of 5.6 x 10-4 S/cm at 30 oC is obtained which is one magnitude larger than that of the waxy P(PEGMA) without any crosslinking agent. Figure 1