Polystyrene Derivatives Research Articles

Minimizing Interfacial Energy Loss and Volatilization of Formamidinium via Polymer-Assisted D-A supramolecular Self-Assembly Interface for Inverted Perovskite Solar Cells with 25.78% Efficiency.

2D perovskite passivation strategies effectively reduce defect-assisted carrier nonradiative recombination losses on the perovskite surface. Nonetheless, severe energy losses are causing by carrier thermalization, interfacial nonradiative recombination, and conduction band offset still persist at heterojunction perovskite/PCBM interfaces, which limits further performance enhancement of inverted heterojunction PSCs. Here, 5,10,15,20-tetrakis(pentafluorophenyl)porphyrin (5FTPP) is introduced between 3D/2D perovskite heterojunction and PCBM. Compared to tetraphenylporphyrin without electron-withdrawing fluoro-substituents, 5FTPP can self-assemble with PCBM at interface into donor-acceptor (D-A) complex with stronger supramolecular interaction and lower energy transfer losses. This rapid energy transfer from donor (5FTPP) to acceptor (PCBM) within femtosecond scale is demonstrated to enlarge hot carrier extraction rates and ranges, reducing thermalization losses. Furthermore, the incorporation of polystyrene derivative (PD) reinforces D-A interaction by inhibiting self-π-π stacking of 5FTPP, while fine-tuning conduction band offset and suppressing interfacial nonradiative recombination via Schottky barrier, dipole, and n-doping. Notably, the multidentate anchoring of PD-5FTPP with FA+, Pb2+, and I- mitigates the adverse effects of FA+ volatilization during thermal stress. Ultimately, devices with PD-5FTPP achieve a power conversion efficiency of 25.78% (certified: 25.36%), maintaining over 90% of initial efficiency after 1000 h of continuous illumination at the maximum power point (65°C) under ISOS-L-2 protocol.

Stimuli-responsive polystyrene derivative for a turbidity-based detection of a nerve agent mimic

Stimuli-responsive polystyrene derivative for a turbidity-based detection of a nerve agent mimic

Towards non-traditional intrinsic luminescence luminogens from polystyrene derivative C5 skeletal polymers and ladder polymers with well-regulated microstructures

With the emergence of new emissive species in many nonconjugated structures, how to efficiently design and manipulate non-traditional intrinsic luminescence luminogens (NTILgens) is of academic importance but a dramatic challenge. As the carbon skeletons in olefin polymers have diverse microstructures that mainly affect molecular packing, the construction of the carbon skeletons is required to regulate the performances of luminescent materials. Our group previously reported the C5 skeletal P-CPVB and its ladder polymer (C-PCPVB) through the anion migrated ring-opening polymerization (AMROP) of 1-cyclopropylvinylbenzene (CPVB) and the cationic cyclization of P-CPVB. Unexpected, after the rigid seven membered rings were constructed among the phenyl rings, the NTIL was observed of the nonconjugated C-PCPVB in the aggregate state under UV light irradiation. The results inspired us to design the polymer luminogens through the construction of carbon skeletons. In present work, the P-CPVBs and their ladder polymers (C-PCPVBs) with different degree of polymerization (DPs) are prepared. Unexpected, P-CPVBs with different DPs were non-emissive in dilute solution but highly emissive with the visible light in the solid state under the UV light irradiation. As predicted, C-PCPVBs with different DPs fluoresced blue emission in the aggregation state. All the P-CPVBs in the solid state showed much higher absolute quantum yields (QY) values than C-PCPVB analogues did. The bright blue emissions in the aggregate state of both C-PCPVBs bearing nonconjugated groups and P-CPVBs bearing poorly conjugated groups could be attributed to the clusterization-triggered emission (CTE), but the mechanisms to generate NTIL were different due to the difference of the carbon skeletons, where the through-spacing conjugation (TSC) and through-spacing interactions (TSI), respectively, contributed to the NTIL of C-PCPVBs and P-CPVBs. In perspective of the property-oriented designability, their derivatives with different electron-donating and -withdrawing substituents (P-CPVB-OCH3/TPSE/yne, C-PCPVB-OCH3/TPSE/yne) when the DPs were fixed at 24 were synthesized and characterized. All the substituted P-CPVBs/C-PCPVBs were demonstrated with the aggregation-induced emission (AIE) effect and blue fluorescence as the unsubstituted P-CPVBs/C-PCPVBs. As desired, the electronic effect of carbon skeletons and their cyclization can affect their maximum emission wavelengths (λem) and the QY. All the λem values were red-shifted whether the carbon skeletons were cyclic or substituted. More importantly, the glass temperature (Tg) and decomposition temperature (Td) of P-CPVB were dramatically improved by the substituents and cyclization analogues. The seven-membered ring and the crosslinking networks of the yne group in the warming up can significantly improve the stability of polymers, contributing to the higher Td value. It should be noted that P-CPVB-yne and C-PCPVB-yne exhibited the much higher Td values, and they showed the higher carbonization yield of 49.78% and 45.25% at 800 ℃, respectively, which would broaden their applications of these nonpolar polymers.

Product Life Cycle Assessment (LCA) as a Tool for Environmental Management

Life Cycle Assessment, included in company environmental management methods, has particular importance in marketing management. Analysis of dangers to the environment through tools such as the LCA method allows for comparisons of alternative company management strategies. LCA is characterised as a technique for environmental management that enables environmental impact assessment of the product, process, industry, and even the comprehensive economic sector. LCA also influences decisions regarding environmental policy modification, but most importantly, it influences a company's marketing activities. The LCA technique is applied the world over with great effectiveness in studying specific phases of a product's life cycles – from 'birth to death'; however, Poland's experience in this domain constitutes continuously developing research areas. The experience of foreign research centres confirms the possibility of applying LCA techniques in supporting environmental risk assessment of innovative technologies where LCA is used to study the environmental impact of a new generation product, i.e. flocculants from polymer wastes. This article presents the results of a study of the effectiveness of applying a new generation of polyelectrolyte (gained from polystyrene waste) in treating industrial wastewater and the LCA environmental impact assessment, which was carried out using SimaPro software. Based on the analysis of the results of the application of sodium salts of sulfone derivatives of polystyrene in the treatment of mine water, it was found that these products significantly reduced the pollution indicators of mine water from KWK1. Accordingly, they provided the basis for the development of technical-scale technology.

Precise synthesis of high Tg adamantane-containing polystyrene derivatives via anionic polymerization

Among the adamantane-containing polystyrene derivatives reported thus far, poly(4-(4-(N-adamantylimino)methyl)phenylstyrene) shows the highest Tg (268 °C).

Toward efficient functionalization of polystyrene backbone through ketene chemistry: Synthesis, characterization, and DFT study

AbstractIn this study, polystyrene was functionalized with Meldrum's acid toward the introduction of the ketenes (CCO) system to its backbone for producing a dramatically reactive intermediate. Meldrum's acid, as a ketene source, was reacted by poly(styrene‐co‐p‐chloromethyl styrene) through a simple nucleophilic reaction to synthesize poly(styrene‐co‐styryl Meldrum's acid). Then, the pendant Meldrum's acid under thermal treatment converted to ketene intermediate resulting in highly reactive polystyrenes derivatives, which rapidly reacted by nucleophilic reagents to afford ultimate organic building blocks. The polystyrene derivatives were characterized using elemental analysis, FT‐IR, high‐resolution solid‐state NMR, thermogravimetric analysis (TGA), and differential thermogravimetric analysis (DTG). To clarify the evolutionary mechanisms of polystyrene products, density functional theory (DFT) method B3LYP with the 6–311++G(2d,p) basis set was used. We studied the preparation of polystyrene model compounds through Meldrum's acid thermolysis and nucleophilic substitution. The kinetic and thermodynamic parameters in all reactions and the structural and electronic properties of all molecules were calculated. These data exhibited that based on Gibbs Free energy values, the structure of syndiotactic polystyrene is more stable than that of isotactic polystyrene. Furthermore, it was found that the presence of an electron donor or acceptor substituent on the polystyrene structure affects the electronic bandgap.

Vertical Alignment of Liquid Crystals on Phenylphenoxymethyl-Substituted Polystyrene-PS Derivatives Structurally Similar to LC Molecules.

A series of polystyrene derivatives containing precursors of liquid crystal (LC) molecules, phenylphenoxymethyl-substituted polystyrene (PPHE#; # = 5, 15, 25, 50, 75, and 100)—where # is the molar content of 4-phenylphenol using polymer modification reactions—were prepared in order to examine the effect of the polymer film, which possess similar LC molecular structure on the LC alignment properties. It was found that the Tg values of the PPHE# were higher than 100 °C due to their aromatic structure in the biphenyl-based PHE moiety. The LC cells fabricated with PPHE5 and PPHE15 films exhibited planar LC alignment. Conversely, LC molecules showed a vertical alignment in LC cells made using the polymer films with phenylphenoxymethyl side groups in the range of 25–100 mol %. The polar surface energies on the PPHE# films can be associated with the vertical LC alignment on the PPHE# films. For example, vertical LC alignment was exhibited when the polar surface energy of the polymer films was less than approximately 4.2 mJ/m2. Aligning stability was observed at 200 °C and UV irradiation of 20 J/cm2 for LC cells made using the PPHE100 film. Therefore, it was found that biphenyl, one of the LC precursors, modified polystyrene derivatives and can produce a next-generation vertical LC alignment system.

Synthesis and properties of helical polystyrene derivatives with amino acid side groups

A series of polystyrene derivatives with chiral amide groups with a controlled molecular weight and narrow molecular weight distribution were synthesized by reversible addition–fragmentation chain transfer (RAFT) radical polymerization.

Syntheses of benzhydryl 2-propanoyl-functionalized trithiocarbonates and its use as chain transfer agents in the RAFT polymerization of styrene

Abstract The preparation of three new benzhydryl 2-propanoyl-functionalized trithiocarbonate RAFT agents, benzhydryl 2-(ethylsulfanylthiocarbonylsulfanyl)propanoate, benzhydryl 2-(butylsulfanylthiocarbonylsulfanyl)propanoate, benzhydryl 2-(dodecylsulfanylthiocarbonylsulfanyl)propanoate is described. The RAFT polymerization of styrene, mediated by the appropriate benzhydryl 2-(alkylsulfanylthiocarbonylsulfanyl)propanoate as the chain transfer agent, with AIBN as initiator at 70 0C, proceeds via reversible-deactivation radical polymerization processes to produce the corresponding α-benzhydryl 2-propanoyl polystyrene derivative, with the benzhydryl ester group introduced at the α-terminus of the polymer chain. Polymerization kinetics measurements show that each RAFT polymerization reaction follows first order rate kinetics with respect to percentage monomer consumption and the number average molecular weights of the functionalized polymers increase linearly with the percentage monomer conversion to produce functionalized polymers with narrow molecular weight distributions. The percentage monomer conversion with time for each polymerization reaction was monitored by 1H NMR spectroscopy by evaluating the consumption of styrene with respect to polymerization time. Post-RAFT polymerization chain end modification of α-benzhydryl 2-propanoyl-functionalized polystyrene by the acid catalyzed ester hydrolysis reactions with concentrated sulfuric acid afforded the corresponding α-carboxyl functionalized polystyrene derivative, with the retention of the thiocarbonylthio moiety at the ω-terminus of the polymer chain. The benzhydryl 2-propanoyl-functionalized trithiocarbonate chain transfer agents and the different functionalized polystyrene derivatives were characterized by 1H NMR, 13C NMR and FTIR spectroscopy, size exclusion chromatography, thin layer chromatography and mass spectrometry measurements.

Effect of Position and Structure of the Terminal Moieties in the Side Group on the Liquid Crystal Alignment Behavior of Polystyrene Derivatives.

We synthesized a series of polystyrene derivatives containing various side groups, such as the 4-(tert-butyl)-phenoxymethyl, 3-(tert-butyl)-phenoxymethyl, 2-(tert-butyl)-phenoxymethyl, 4-cumyl-phenoxymethyl, and 4-trityl-phenoxymethyl groups, through a polymer modification reaction to examine the liquid crystal (LC) alignment of these derivatives. In general, the vertical LC alignment on polymer films can be affected by the position and structure of the terminal moiety of the polymer side group. For example, the LC cells fabricated with 4-(tert-butyl)-phenoxymethyl-substituted polystyrene having a tert-butyl moiety as a para-type attachment to the phenoxy groups of the polystyrene derivatives exhibited vertical LC alignment, whereas the LC cells prepared from 3-(tert-butyl)- and 2-(tert-butyl)-phenoxymethyl-substituted polystyrene films exhibited planar LC alignment. In addition, the LC cells fabricated from 4-cumyl- and 4-trityl-phenoxymethyl-substituted polystyrene films with additional phenyl rings in the side groups exhibited planar LC alignment, in contrast to the LC alignment of the (tert-butyl)-phenoxymethyl-substituted polystyrene series. The vertical LC orientation was well correlated with the surface energy of these polymer films. For example, vertical LC orientation, which mainly originates due to the nonpolar tertiary carbon moiety having bulky groups, was observed when the surface energy of the polymer was lower than 36.6 mJ/m2.

Vertical Orientation of Liquid Crystal on Polystyrene Substituted with n-alkylbenzoate-p-oxymethyl Pendant Group as a Liquid Crystal Precursor.

We synthesized a series of polystyrene derivatives modified with precursors of liquid crystal (LC) molecules via polymer modification reactions. Thereafter, the orientation of the LC molecules on the polymer films, which possess part of the corresponding LC molecular structure, was investigated systematically. The precursors and the corresponding derivatives used in this study include ethyl-p-hydroxybenzoate (homopolymer P2BO and copolymer P2BO#, where # indicates the molar fraction of ethylbenzoate-p-oxymethyl in the side chain (# = 20, 40, 60, and 80)), n-butyl-p-hydroxybenzoate (P4BO), n-hexyl-p-hydroxybenzoate (P6BO), and n-octyl-p-hydroxybenzoate (P8BO). A stable and uniform vertical orientation of LC molecules was observed in LC cells fabricated with P2BO#, with 40 mol% or more ethylbenzoate-p-oxymethyl side groups. In addition, the LC molecules were oriented vertically in LC cells fabricated with homopolymers of P2BO, P4BO, P6BO, and P8BO. The water contact angle on the polymer films can be associated with the vertical orientation of the LC molecules in the LC cells fabricated with the polymer films. For example, vertical LC orientation was observed when the water contact angle of the polymer films was greater than ~86°. Good orientation stability was observed at 150 °C and with 20 J/cm2 of UV irradiation for LC cells fabricated with the P2BO film.

Vertical Orientation of Liquid Crystal on Comb-Like 4-(trans-4-alkylcyclohexyl)phenoxymethyl-substituted Polystyrene Containing Liquid Crystal Precursor.

We synthesized a series of polystyrene derivatives modified with precursors of liquid crystal (LC) molecules, including 4-(trans-4-ethylcyclohexyl)phenol (homopolymer PECH and copolymer PECH#; # = 5, 10, 15, 20, 40, 60, and 80, where # indicates the molar fraction of 4-(trans-4-ethylcyclohexyl)phenoxymethyl in the side chain), 4-(trans-4-propylcyclohexyl)phenol (PPCH), 4-(trans-4-butylcyclohexyl)phenol (PBCH), and 4-(trans-4-amylcyclohexyl)phenol (PAmCH) via polymer modification reactions in order to investigate the orientation of LC molecules on polymer films exhibiting part of the LC molecular structure. A stable and uniform vertical orientation of LC molecules was observed in LC cells fabricated with PECH#, having 15 mol% or more of 4-(trans-4-ethylcyclohexyl)phenoxymethyl side groups. In addition, the vertical orientation of LC molecules was observed in LC cells fabricated with homopolymers of PECH, PPCH, PBCH, and PAmCH. The water contact angle on the polymer films could be associated with the vertical orientation of the LC molecules in the LC cells fabricated with polymer films. For example, a vertical LC orientation was observed when the water contact angle of the polymer films was higher than ~81°. Good orientation stability was observed at 200 °C and 15 mW/cm2 of UV irradiation for LC cells fabricated with PECH films.

Synthesis and antimicrobial activity of chalcone containing polystyrene

Three different 4-propargyloxychalcones have been prepared starting from 4-propargyloxy benzaldehyde and chalcones with proper chemical transformation. Polystyrenes containing biologically active chalcone moiety in their structures have been successfully synthesised by the Click reaction from the 4-propargyloxychalones (terminal alkyne) and azido end-functional polystyrene (PS-N 3 ). All the desired products have been obtained with good yield and purity. The structure of the 4-propargyloxychalcones and the chalcone containing polystyrenes have been characterized by FT-IR, 1 H NMR and UV-Vis spectroscopy. The antibacterial activity of the synthesized 4-propargyloxychalcones their polystyrene derivatives have been evaluated against two bacterial strains, Staphylococcus aureus (Gram-positive) and Escherichia coli (Gram-negative). The results reveal that the tested chalcones and their polystyrene derivatives have moderate antimicrobial activity.

Vertical Orientation of Liquid Crystal on 4-n-Alkyloxyphenoxymethyl-Substituted Polystyrene Containing Liquid Crystal Precursor

We synthesized a series of polystyrene derivatives that were modified with precursors of liquid crystal (LC) molecules, such as 4-ethyloxyphenol (homopolymer PEOP and copolymer PEOP#; # = 20, 40, 60, and 80, where # indicates the molar fraction of 4-ethyloxyphenoxymethyl in the side chain), 4-n-butyloxyphenol (PBOP), 4-n-hexyloxyphenol (PHOP), and 4-n-octyloxyphenol (POOP), via polymer modification reaction to investigate the orientation of LC molecules on polymer films, exhibiting part of the LC molecular structure. LC molecules showed a stable and uniform vertical orientation in LC cells fabricated with polymers that have 4-ethyloxyphenoxymethyl in the range of 40–100 mol%. In addition, similar results were obtained in LC cells fabricated with homopolymers of PEOP, PBOP, PHOP, and POOP. The vertical orientation of LC molecules in LC cells fabricated with polymer films correlated to the surface energy of polymer films. For example, vertical LC orientation was observed when the total surface energies of the polymer films were lower than approximately 43.2 mJ/m2. Good alignment stabilities were observed at 150 °C and 20 J/cm2 of ultraviolet irradiation for LC cells fabricated with PEOP film.

Preparation and characterization of cross-linked plastic scintillators

Plastic scintillators are efficient and low-cost detectors suitable for radiation detection. Obviously and as for all detectors, plastic scintillators display both advantages and drawbacks. Among disadvantages, it is known that their use is prohibited at elevated temperatures (e.g. 100 °C) due to their organic, polymeric nature. Commercial providers recommend therefore using plastic scintillators at temperatures below 60 °C to mitigate this degradation. We wish to present herein the preparation and the characterization of plastic scintillators based from cross-linked polystyrene derivatives, which allow them stability at high temperatures (i.e. tested up to 110 °C) while maintaining their scintillation properties. Their preparation, physical characterization, and relative scintillation yield estimated by radioluminescence is reported, so as to determine the influence of the cross-linking on these properties. In addition, the materials are benchmarked with two commercial plastic scintillators from Eljen technology: all-purpose EJ-200 and cross-linked EJ-244.

Fast and Regioselective Polymerization of para-Alkoxystyrene by Palladium Catalysts for Precision Production of High-Molecular-Weight Polystyrene Derivatives

Polymerization of polar vinyl monomers by a coordination–insertion approach is a topic of fundamental importance to the field of polymer synthesis. Herein, we initially report the coordination–inse...

RAFT polymerization of styrene mediated by naphthyl-functionalized trithiocarbonate RAFT agents

New oxazolyl benzhydryl and oxazolyl benzyl-functionalized trithiocarbonate RAFT agents, 1-(butylsulfanylthiocarbonylsulfanyl)-1-[4-(4,5-dihydro-4,4-dimethyl-2-oxazolyl)phenyl]-1-phenylmethane and 2-[4-((butylsulfanylthiocarbonylsulfanyl)methyl)phenyl]-4,5-dihydro-4,4-dimethyloxazole, were prepared and employed as chain transfer agents in RAFT polymerization reactions. The RAFT polymerization of styrene, mediated by the appropriate oxazolyl-functionalized trithiocarbonate RAFT agent with AIBN as initiator at 70 °C, proceeded via controlled/living polymerization processes to produce the corresponding α-oxazolyl-functionalized polystyrene derivative, with the oxazolyl group introduced at the α-terminus of the polymer chain and the absence of any unfunctionalized polystyrene. Post-RAFT polymerization chain end modification of α-oxazolyl-functionalized polystyrene by acid-catalyzed hydrolysis reactions with dilute hydrochloric acid afforded the corresponding α-carboxyl-functionalized polystyrene derivative, with the retention of the butylsulfanylthiocarbonylsulfanyl moiety at the ω-terminus of the polymer chain. Polymer kinetic measurements show that each RAFT polymerization reaction follows first-order rate kinetics with respect to the percentage monomer consumption. The oxazolyl-functionalized benzhydryl fragmentation radical provides better control of the re-initiation of the polymerization of styrene than the oxazolyl-functionalized benzyl fragmentation radical. After consumption of the RAFT agent, the number average molecular weights of the functionalized polymers increases linearly with the percentage monomer conversion to produce α-oxazolyl-functionalized polystyrene derivatives with narrow molecular weight distributions. New oxazolyl benzhydryl and oxazolyl benzyl-functionalized trithiocarbonate RAFT agents, 1-(butylsulfanylthiocarbonylsulfanyl)-1-[4-(4,5-dihydro-4,4-dimethyl-2-oxazolyl)phenyl]-1-phenylmethane and 2-[4-((butylsulfanylthiocarbonylsulfanyl)methyl)phenyl]-4,5-dihydro-4,4-dimethyloxazole, were prepared and employed as chain transfer agents in RAFT polymerization reactions. The RAFT polymerization of styrene, mediated by 1-(butylsulfanylthiocarbonylsulfanyl)-1-[4-(4,5-dihydro-4,4-dimethyl-2-oxazolyl)phenyl]-1-phenylmethane or 2-[4-((butylsulfanylthiocarbonylsulfanyl)methyl)phenyl]-4,5-dihydro-4,4-dimethyloxazole as chain transfer agents with AIBN as the initiator at 70 °C, proceeds via a controlled/living polymerization process to produce the corresponding α-oxazolyl-functionalized polystyrene derivative, with the oxazolyl group introduced at the α-terminus of the polymer chain.

Poly(ionic liquid) Based Anodic Binder with Enhanced Cyclability for Lithium-Ion Batteries

The commercialization of the lithium-ion batteries (LiBs) by Sony in early 90s has led to revolution in technology in past two decades. Due to its higher gravimetric and volumetric energy, lower self-discharge, absence of memory effect and flexibility in the design has made this class of batteries very popular. In order to achieve improved efficiency and safety, a plethora of electrode materials and electrolytes are designed. In addition to these materials, binders play a very crucial role in the performance of the LiBs. Binders are polymers that maintain the integrity of electrodes by binding the electrode material together and the electrode laminate to the current collector. They assist in Li-ion mobility and solid electrolyte interface formation. Poly(vinylidene fluoride) commonly known as PVDF is the commercial choice of binder due to its cost in addition to its thermal, chemical and electrochemical stabilities. However, a major drawback of using PVDF is its dissolution into electrolyte leading to the loss of electrode integrity and capacity fade on long cycling. Also, due to the fluorinated framework, fluorinated salts are formed on electrode surface and poses an environmental threat.1 In order to mitigate this setback, a variety of both natural and synthetic polymers are currently being explored as binders for LiBs.2 Poly(ionic liquid)s (PILs) are emerging class of material with polymeric backbone and an ionic liquid unit attached to it. The structural diversity is vast due to the availability of innumerous ionic liquids and polymeric backbones. By varying the structure, tuning of the properties can be achieved. The current work focusses on developing a multifunctional binder which in addition to binding the electrode material, can assist the formation of a better electrode-electrolyte interface. An allylimidazolium tagged polystyrene derivative (PVBCAImTFSI) was prepared by quaternization reaction of the allylimidazole with poly(vinylbenzyl chloride). The obtained polymer was characterized with FT-IR spectroscopy and energy-dispersive X-ray spectroscopy (EDX). Structural optimization and electronic properties were calculated using Gaussian 09. Electrochemical characterization was carried out using 2025-coin cells with graphite anodes fabricated with PIL and PVDF binders. Electrochemical Impedance spectroscopy (EIS) and Dynamic Electrochemical Impedance Spectroscopy (DEIS) were carried out to understand the nature of the electrode-electrolyte interface. Cyclic voltammetry was carried out to understand various redox processes in the potential range of 10 – 2100 mV vs Li/Li+ at a scan rate of 0.1 mV/s. Linear-Sweep Voltammetry was carried out to evaluate the electrochemical stability of the binder in the potential window of 0 – 7000 mV vs Li/Li+. Figure shows the CV measurements which indicated a decreased irreversible electrolyte reduction (shown in the circle) for the half-cells with PVBCAImTFSI binder as compared to that of the PVDF binder. Also, the intercalation-deintercalation overpotential was reduced by about 90 mV in the former case. To further understand the diffusion of the Li+ ion in the active material, CV based scan rate studies were carried out. The diffusion coefficient calculated for the PVBCAImTFSI based electrodes was found to be 40% higher than that of the PVDF based electrodes. These indicated formation of a thinner and more robust SEI. The impedance due to the SEI, RSEI values were estimated by fitting the DEIS data to the equivalent electric circuit models (EECMs). These values for PVBCAImTFSI were found to be lesser than that of PVDF at all potentials indicating formation of better SEI in the former case. Due to the high wettability of PVBCAImTFSI and better SEI characteristics the present system led to an enhanced charge-discharge performance in terms of cyclability as well as stability. A discharge capacity of 210 mAh/g was obtained at 1C rate for PVBCAImTFSI based half-cells and about 95% capacity retention was observed after 500 cycles. Whereas, PVDF based half-cells exhibited 140 mAh/g of discharge capacity and 40% capacity retention. Even the rate studies suggest that PVBCAImTFSI based electrodes to have higher stability. In conclusion, an allylimidazolium based multifunctional poly(ionic liquid) was synthesized and used as an anodic binder for graphite electrodes. The anodic half-cells with PVBCAImTFSI displayed about 210 mAh/g of discharge capacity and a 95% retention after 500 cycles at 1C rate. Its enhanced charge-discharge performance can be attributed to its improved interaction with the electrolyte and a thinner SEI formed. The results obtained in this work indicates that PVBCAImTFSI can potentially replace PVDF as a binder in LiBs. (1) Patnaik, S. G.; Vedarajan, R.; Matsumi, N. J. Mater. Chem. A, 5 , 17909 (2017). (2) Chen, H.; Ling, M.; Hencz, L.; Ling, H. Y.; Li, G.; Lin, Z.; Liu, G.; Zhang, S. Chem. Rev., 118 (18), 8936 (2018). Figure 1

Bio-inspired multiple complementary hydrogen bonds enhance the miscibility of conjugated polymers blended with polystyrene derivatives

In this study, we prepared bio-inspired multiple-hydrogen-bonded blends of a thymine (T)-functionalized PTC-T conjugated polymer, synthesized through Suzuki coupling polymerization, and an adenine (A)-functionalized polystyrene (PVBA) homopolymer, synthesized through free radical polymerization, in each case applying also alkylene–azide click reactions. The resulting PTC-T/PVBA blends displayed a single glass transition temperature at all blend compositions (as determined using differential scanning calorimetry), suggesting that the miscibility arose because of the strong multiple hydrogen bonding between the A and T groups of the PVBA and PTC-T components, respectively. 1H NMR and FTIR spectroscopy provided evidence for such A–T binary hydrogen bonding in the PTC-T/PVBA miscible domains, both in solution and in the solid state. Furthermore, the incorporation of PVBA into PTC-T affected the photophysical properties of the luminescent film: the physically crosslinked structure formed from the multiple hydrogen bonding interactions improved the quantum yield through phase-miscible behavior.

Iodinated Polystyrene for Polymeric Charge Transfer Complexes: Toward High-Performance Near-UV and Visible Light Macrophotoinitiators

In recent works, charge transfer complexes (CTCs) have proved to be useful photoinitiating agents to trigger free radical polymerization. However, because of their low molecular weights, migration issues remain very important. In line with pressing migration concerns around photoinitiating systems (e.g., in 3D polymer networks), we report here the use of the first polymeric CTC based on iodinated polystyrene/amine interactions. This study shows the formation of the CTC between the polystyrene derivative (electron acceptor EA) and a tertiary alkylamine (electron donor ED); the ability of this EA/ED couple in a CTC to act as a photoinitiator for the polymerization of multifunctional acrylates upon LED@405 nm irradiation is investigated. Examples of applications to 3D-resolved laser write of thick controlled samples (1 mm) are provided.