Neutral Poly Research Articles

Intestinal distribution of anionic, cationic, and neutral polymer-stabilized nanocarriers measured with a lanthanide (europium) tracer assay

Nanocarriers, more commonly called nanoparticles (NPs), have found increasing use as delivery vehicles which increase the oral bioavailability of poorly water-soluble and peptide therapeutics. Therapeutic bioavailability is commonly assessed by measuring plasma concentrations that reflect the absorption kinetics. This bioavailability is a convolution of the gastrointestinal distribution of the NP vehicle, the release rate of the encapsulated therapeutic cargo, and the absorption-metabolism-distribution kinetics of the released therapeutic. The spatiotemporal distribution of the NP vehicle in the gastrointestinal tract is not well studied and is a buried parameter in PK studies used to measure the effectiveness of an NP formulation. This work is a study of the intestinal distribution and fate of orally dosed NPs in male CD-1 mice over 24 h. NPs have identical hydrophobic cores – composed of poly(styrene) homopolymer, a naphthalocyanine dye, and oleate-coated europium oxide colloids – with one of four different surface stabilizers: neutral poly(styrene)-block-poly(ethylene glycol) (PS-b-PEG), moderately negative hydroxypropyl methylcellulose acetate succinate (HPMCAS), highly negative poly(styrene)-block-poly(acrylic acid) (PS-b-PAA), and highly cationic adsorbed chitosan HCl on PS-b-PAA stabilized NPs. NP hydrodynamic diameters are all below 200 nm, with some variation attributable to the molecular properties of the stabilizing polymer. The encapsulated hydrophobic europium oxide colloids do not release soluble europium ions, enabling the use of highly sensitive inductively coupled plasma mass spectrometry (ICP-MS) to detect NP concentrations in digested biological tissues.Highly anionically-charged PAA and cationically-charged chitosan stabilized NPs showed statistically significant increased retention compared to the neutral PEG-stabilized NPs at p < 0.05 significance and (1-β) > 0.95 power. HPMCAS-stabilized NPs showed statistically insignificant greater retention than PEG-stabilized NPs, and all NP formulations showed clearance from the intestines within 24 h. Different surface charges preferentially reside in different segments of the intestines, where cationic chitosan-stabilized NPs showed increased retention in the small intestines (ileum) and anionic PAA-stabilized NPs in the large intestines (caecum and colon). Modifying the surface charge of a NP can be used to modulate mucoadhesion, total retention, and intestinal segment specific retention, which enables the rational design of delivery vehicles that maximize residence times in appropriate locations.

A Strategic Blend of Stabilizing Polymers to Control Particle Surface Charge for Enhanced Mucus Transport and Cell Binding.

Mucus layers, viscoelastic gels abundant in anionic mucin glycoproteins, obstruct therapeutic delivery across all mucosal surfaces. We found that strongly positively charged nanoparticles (NPs) rapidly adsorb a mucin protein corona in mucus, impeding cell binding and uptake. To overcome this, we developed mucus-evading, cell-adhesive (MECS) NPs with variable surface charge using Flash NanoPrecipitation, by blending a neutral poly(ethylene glycol) (PEG) corona for mucus transport with a small amount, 5 wt%, of polycationic dimethylaminoethyl methacrylate (PDMAEMA) for increased cell targeting. In vitro experiments confirmed rapid mucus penetration and binding to epithelial cells by MECS NPs, suggesting a breakthrough in mucosal drug delivery.

Stable Operation and Enhanced Sensitivity via Composite Structure Design for Efficient Photoplethysmography and Motion Sensors

Healthcare sensors have attracted lots of interests owing to saving a patient's life by continuously monitoring the patient's health via early diagnosis of the symptoms by using healthcare sensors. Many health-care sensors are available in wearable application that can monitor continuously patient health. There are some common parameters such as a heart rate and human motion that are used to monitor human activity.In order to realize stable operation of health-care sensors, material designs are required considering human-body compatibility. In this research, light-sensors fabricated from low-toxicity organic materials by introducing neutral poly(3,4-ethylenedioxythiophene)-(polystyrene sulfonate) (PEDOT-(PSS)) to improve human-body compatibility as well as to strengthen photoplethysmography (PPG) signal. [1] Neutral PEDOT-(PSS) with heterocyclic 1,3-diazole (HDZ) enhances the polymerization degree, carrier mobility, and other physicochemical properties. Consequently, the presented OPD-based PPG sensor has the ability to diagnose blood circulation status and cardiovascular diseases.Second, we fabricate motion sensors by utilizing metallic glass, i.e., amorphous metallic alloy, which is an alloy composition without grain boundaries and long-range ordering. The unique structure of metallic glass results in excellent tensile strength and strain-resistivity as well as chemical stability to those of conventional metals. The Al-Sm MG-based sensors results in enhanced sensitivity and considerable device stability, because of its amorphous phase. [2][1] Adv. Funct. Mater. 2023, 10.1002/adfm.202309271[2] Electrochimica Acta, 2023, 446, 142053

Emulsion Stabilized by Biocompatible and Stimuli-Responsive Poly(N-vinylcaprolactam)-Based Microgels: Effects of Electrostatic Repulsion and Deformability on Emulsion Stability.

Microgels have been widely used for stabilizing emulsions due to their softness and stimulus responsiveness. Although ultrastable emulsions have been prepared by microgel nanoparticles, the role of electrostatic interactions on emulsion stability is still a controversial topic and further investigation of the effect of microgel deformability is required. In the present study, neutral poly(N-vinylcaprolactam) (PVCL) and charged poly(N-vinylcaprolactam)-co-methacrylic acid (P(VCL-co-MAA)) microgels were synthesized and further used as emulsifiers to stabilizing emulsion. The P(VCL-co-MAA) microgel has a swelling ratio larger than that of the PVCL microgel in water. The nanomechanical properties of the microgels in water were characterized by atomic force microscopy with using the tip of different radii. The result reveals that the P(VCL-co-MAA) microgel is more deformable than the PVCL counterpart. Stability tests of the emulsions showed that below the volume phase transition temperature (VPTT) of the microgels, both microgel types can stabilize the emulsions under various conditions. Unexpectedly, most of the emulsions still remain stable above the VPTT. Further increasing the temperature to 60 °C, P(VCL-co-MAA) microgel emulsions remained stable at a pH value above the pKa of MAA while the emulsion was unstable below the pKa. However, phase separation occurs in PVCL microgel-stabilized emulsions at 60 °C. These results demonstrate that electrostatic repulsion and deformability of the microgels can enhance the emulsion stability, providing insights into the rational design and preparation of ultrastable Pickering emulsions.

Charge transport in electrospinning of polyelectrolyte solutions.

This study elucidates the electrical charge transport during electrospinning of weak polyelectrolyte (poly(acrylic acid) (PAA)) solutions by employing current emission measurements. With pH variation, the PAA ionization degree could be controlled from uncharged at low pH to weakly charged at intermediate solution pH. Electrospinning neutral poly(vinylpyrrolidone) (PVP) as a reference polymer solution confirmed established current-flow rate scaling relationships as shown by De La Mora and Loscertales (1994), I ∼ (γKQ)ν, independent of the applied electric field polarity, where ν = 0.5, K is the conductivity, γ is the surface tension, Q is the flow rate, and I is the current. Similarly, the uncharged PAA did not display any polarity dependence, yet ν ≈ 0.8. Negatively charged PAA, however, showed a marked deviation in the current-flow rate behavior, which was affected by the applied electric field polarity. In the case of negative polarity, ν = 0.99, whereas for a positive polarity ν = 0.68. Similarly, the voltage required for stable cone-jet electrospinning of charged PAA was significantly higher in the negative polarity configuration for all tested flow rates (300-1600 μL h-1). As opposed to merely surface charges typically considered when electrospinning leaky dielectric fluids, as suggested by Melcher and Taylor (1969), our results suggest that the measured current is also affected by volumetric charges from charged PAA in the bulk of the jet. The proposed additional charge transport might affect the orientational order within PE-based nanofibers and their diameter.

On the origin of the low immunogenicity and biosafety of a neutral α-helical polypeptide as an alternative to polyethylene glycol

Poly(ethylene glycol) (PEG) is a prominent synthetic polymer widely used in biomedicine. Despite its notable success, recent clinical evidence highlights concerns regarding the immunogenicity and adverse effects associated with PEG in PEGylated proteins and lipid nanoparticles. Previous studies have found a neutral helical polypeptide poly(γ-(2-(2-(2-methoxyethoxy)ethoxy)ethyl l-glutamate), namely L-P(EG3Glu), as a potential alternative to PEG, displaying lower immunogenicity. To comprehensively assess the immunogenicity, distribution, degradation, and biosafety of L-P(EG3Glu), herein, we employ assays including enzyme-linked immunosorbent assay, positron emission tomography-computed tomography, and fluorescent resonance energy transfer. Our investigations involve in vivo immune responses, biodistribution, and macrophage activation of interferon (IFN) conjugates tethered with helical L-P(EG3Glu) (L20k-IFN), random-coiled DL-P(EG3Glu) (DL20k-IFN), and PEG (PEG20k-IFN). Key findings encompass: minimal anti-IFN and anti-polymer antibodies elicited by L20k-IFN; length-dependent affinity of PEG to anti-PEG antibodies; accelerated clearance of DL20k-IFN and PEG20k-IFN linked to anti-IFN and anti-polymer IgG; complement activation for DL20k-IFN and PEG20k-IFN but not L20k-IFN; differential clearance with L20k-IFN kidney-based, and DL20k-IFN/PEG20k-IFN accumulation mainly in liver/spleen; enhanced macrophage activation by DL20k-IFN and PEG20k-IFN; L-P(EG3Glu) resistance to proteolysis; and safer repeated administrations of L-P(EG3Glu) in rats. Overall, this study offers comprehensive insights into the lower immunogenicity of L-P(EG3Glu) compared to DL-P(EG3Glu) and PEG, supporting its potential clinical use in protein conjugation and nanomedicines.

Fabrication of a Printed Heater Using a Composite of Silver Nanowires and Neutral PEDOT:PSS

In this work, a low resistance heater based on a composite of silver nanowires (Ag NWs) and neutral poly (3,4-ethylenedioxythiophene) poly(styrene sulphonate) (PEDOT:PSS) is fabricated. Pure Ag NWs have poor substrate adhesion, poor environmental and thermal stability, and high surface roughness. Local hotspots at wire junctions also leads to uneven joule heating. These disadvantages are overcome by blending the NWs with PEDOT:PSS. Specifically, neutral PEDOT:PSS is used in this work as it is less hygroscopic and possess greater environmental stability compared to the conventionally used acidic PEDOT:PSS. The composite is synthesized as a stable printable dispersion and deposited on a flexible polyethylene terephthalate (PET) substrate using an extrusion-based direct write system. Film thickness was optimized to achieve low sheet resistance and good adhesion and it is laminated with polydimethylsiloxane (PDMS) for environmental protection. The heater shows uniform temperature distribution with a short response time and low operating voltage. Temperature distribution modelling was carried out using COMSOL and correlated well with the experimental data. The heater also exhibits good repeatability and cyclic thermal stability. A prototype device with temperature cut-off and feedback was also implemented using an Arduino controller.

Robust Polyion Complex Vesicles (PICsomes) Based on PEO‐b‐poly(amino acid) Copolymers Combining Electrostatic and Hydrophobic Interactions: Formation, siRNA Loading and Intracellular Delivery

AbstractTwo pairs of oppositely charged PEO‐b‐poly(amino acid) copolymers with neutral poly(ethylene oxide) block and polypeptide block composed of the hydrophobic l‐phenylalanine (Phe) amino acid mixed with either negative l‐glutamic acid (Glu) or positive l‐lysine (Lys) units are synthesized. N‐carboxyanhydride (NCA) ring opening polymerization is performed with either PEO46‐NH2 or PEO114‐NH2 macroinitiators, leading respectively to PEO46‐b‐P(Glu100‐co‐Phe65) and PEO46‐b‐P(Lys100‐co‐Phe65), and PEO114‐b‐P(Glu60‐co‐Phe40) and PEO114‐b‐P(Lys60‐co‐Phe40). Polyion complexes (PIC) formed at near charge equilibrium led to vesicle formation (PICsomes), as shown by DLS, zetametry, and TEM. The good stability of PICsomes, even in high salinity media, is interpreted by ππ stacking hydrophobic interactions between the Phe residues, playing the role of “physical cross‐linking”. These PICsomes are successfully loaded with small interfering ribonucleic acid (siRNA) directed against firefly luciferase enzyme expression. They also exhibit minimal cell cytotoxicity while superior silencing efficacy is shown by cell bioluminescence assay as compared to free siRNA and a standard lipofectamine‐siRNA complex. As such, self‐assembly of oppositely charged PEO‐b‐poly(amino acids) block copolymers enables forming PICsomes of high stability thanks to ππ interactions of the Phe co‐monomer in the polypeptide block, with high potential as biocompatible nanocarriers for RNA interference.

A fluorescent turn-on sensor for mercury (II) ions in near neutral poly(metharylic acid) solution

The conformational change of poly (methacrylic acid) (PMAA) at various pH values is well studied; however, the application of PMAA in the field of analytical chemistry has been very limited. This investigation takes advantage of the conformational change of PMAA at various pH levels and the conformational change induced by metal ions. By adjusting the pH, thiophene-phenylanilide-acridinium molecules can serve as turn-on sensors for Hg2+ ions. In pH 7.4 buffer with PMAA molecules, the sensor is selectively turned on by Hg2+ ions to display strong charge shift state (CSH) emission at 560 nm. The intensity shows linear response to the concentration of Hg2+ ions between 0.020 mM and 0.151 mM with a detection limit in nanomolar range. The photophysical properties of sensor molecules in PMAA/mercury (II) mixture at near neutral pH are comparable to those in PMAA solution in acidic condition without mercury (II) ions. The effect of pH, temperature, polymer size, and polymer concentration on emission intensity were investigated. The sensor showed excellent percent recovery (98.4 % to 103 %) of spiked mercury (II) ions in real water samples. The sensing mechanism is likely through intrachain and interchain coordination of mercury (II) ions with the carboxyl groups on the side chain of PMAA to induce an extended coil conformation of PMAA. Calculations support the conclusion that the size and geometry of the binding sites formed inside PMAA are suitable to incorporate sensor molecules and enhance the charge shift state emission of sensor molecules.

Effects of Neutral, Anionic and Cationic Polymer Brushes Grafted from Poly(para-phenylene vinylene) and Poly(para-phenylene ethynylene) on the Polymer's Photoluminescent Properties.

The conformation of a fluorescent polymer, in the solid state or in solution, plays a critical role in the polymer’s fluorescent properties. Thus, grafted side chains on a fluorescent polymer can directly influence its optical properties. In this study, the effect of grafted polymeric side chains on the photoluminescent properties of poly(para-phenylene vinylene) (PPV) and poly(para-phenylene ethynylene) (PPE) were investigated. Low- and high-molecular-weight grafts of neutral poly(n-butyl acrylate), cationic poly(trimethylaminoethyl methacrylate) and anionic poly(sulfopropyl acrylate) were grafted onto PPVs and PPEs, and the effect of the grafting on the graft copolymer’s absorption and emission wavelengths, the fluorescence intensity and the quantum yield were studied. The results indicate that in the case of the ionic grafts, contrary to the expectations, the polymers have a reduced quantum yield. This contrasts with the copolymers with uncharged side chains (PnBA), where a major increase in the quantum yield is seen for the self-quenching conjugated pristine polymers. These results reinforce that the molecular conformation of the polymer in a solid or solution plays a critical role in fluorescent polymers photoluminescent properties.

Shielding behavior of electrokinetic properties of polystyrene latex particle by the adsorption of neutral poly(ethylene oxide)

To understand the shielding of electrokinetics of colloidal particles by polymer coating, we measured the electrophoretic mobility of negatively charged polystyrene sulfate latex (PSL) adsorbed with electrostatically neutral polyethylene oxide (PEO) chains with various molecular weights under different ionic strengths. We confirmed that substantial adsorbed neutral polymer on the particle surface would decrease the absolute value of electrophoretic mobility. Even though the polymer layer is sufficiently thicker compared to the thickness of electric double layer (EDL), the electrophoretic mobility (EPM) never vanishes, which indicates the incompleteness of electrokinetic shielding by an adsorbed neutral polymer. To relate such interesting phenomena, a simple mathematical model has been proposed to evaluate the electrophoretic mobility, assuming the presence of a scaling structure of adsorbed permeable polymer layer does not influence the Poisson–Boltzmann distribution of ions in the electric double layer (EDL). An analytical expression of electrophoretic mobility under Debye-Hu¨ckel approximation has been derived using the method of Ohshima-Kondo theory, which successfully justifies the experimentally obtained data.

Optimal Pole-Swapping in Bipolar DC Networks Using Discrete Metaheuristic Optimizers

Bipolar direct current (DC) networks are emerging electrical systems used to improve the distribution capabilities of monopolar DC networks. These grids work with positive, negative, and neutral poles, and they can transport two times the power when compared to monopolar DC grids. The distinctive features of bipolar DC grids include the ability to deal with bipolar loads (loads connected between the positive and negative poles) and with unbalanced load conditions, given that the loads connected to the positive and neutral poles are not necessarily equal to the negative and neutral ones. This load imbalance deteriorates voltages when compared to positive and negative poles, and it causes additional power losses in comparison with balanced operation scenarios. This research addresses the problem of pole-swapping in bipolar DC networks using combinatorial optimization methods in order to reduce the total grid power losses and improve the voltage profiles. Bipolar DC networks with a non-solidly grounded neutral wire composed of 21 and 85 nodes are considered in the numerical validations. The implemented combinatorial methods are the Chu and Beasley genetic algorithm, the sine-cosine algorithm, and the black-hole optimization algorithm. Numerical results in both test feeders demonstrate the positive effect of optimal pole-swapping in the total final power losses and the grid voltage profiles. All simulations were run in the MATLAB programming environment using the triangular-based power flow method, which is intended for radial distribution system configurations.

Surface grafting with diverse charged chemical groups mitigates calcium phosphate scaling on reverse osmosis membranes during municipal wastewater desalination

Calcium phosphate scaling on reverse osmosis (RO) membranes during the desalination of municipal wastewater remains a major problem. This study modified RO membranes by graft polymerization using hydrophilic methacrylate monomers to reduce scaling and investigated the effects of surface charge and exposed functional groups on scaling during municipal wastewater desalination. Grafting was performed using negatively charged, neutral, positively charged, and mixed charge monomers. Testing the modified membranes during RO desalination of a solution simulating treated domestic wastewater effluents from the Shafdan wastewater reclamation plant in Israel revealed improved antiscaling performance by grafted membranes compared with the pristine (unmodified) membrane. In particular, membranes grafted using neutral and mixed charge monomers showed the best antiscaling tendencies: 25.6% and 27.6% decrease in flux, respectively, compared with a 59.1% decrease using the pristine membrane. These results, together with physico-chemical characterization, suggested that calcium phosphate precipitation and scaling on the grafted RO membranes are driven mainly by electrostatic and dipole–dipole interactions between charged chemical groups exposed on the membrane surface and ionic species in the test solution; these interactions are minimized in membranes grafted with neutral or mixed charge poly (methacrylate) groups, resulting in enhanced antiscaling performance. This study provides insight into the antiscaling mechanisms of hydrophilic poly (methacrylate) chains grafted on RO membranes, and thus can potentially aid efforts to mitigate calcium phosphate scaling during RO desalination of municipal wastewater. • Diverse charged monomers grafted on RO membrane to mitigate Ca 3 (PO 4 ) 2 scaling. •Grafted membranes exhibit enhanced performance in RO wastewater desalination. •Neutral and mixed-charge grafted polymers show lowest flux decline. •Electrostatic interactions of surface functional groups with ions dominate scaling.

Triblock Copolymer Micelles with Tunable Surface Charge as Drug Nanocarriers: Synthesis and Physico-Chemical Characterization.

Polymeric micelles have gained increasing interest as efficient drug delivery systems for cancer treatment and diagnosis. The aim of the present study was to construct and to evaluate novel polymeric nanosized drug carriers with tunable surface charges. Initially, amphiphilic triblock copolymers with predetermined molar mass characteristics were synthesized by applying controlled polymerization techniques. The copolymers self-assembled in aqueous media into core–shell spherical micelles, comprising a biodegradable hydrophobic poly(D,L-lactide) core, positively charged middle layer of poly((2-dimethylamino)ethyl methacrylate), and an outer shell of neutral hydrophilic poly(oligo(ethylene glycol) methyl ether methacrylate), with various densities of the short polyether side chains. The block copolymer micelles with average diameters of about 70 nm and surface charges varying from strongly positive to neutral were characterized and loaded with the model, natural, hydrophobic drug curcumin. Characteristics such as drug loading efficiency, in-vitro drug release profiles, and stability under physiological conditions were evaluated and discussed in terms of nanocarriers’ composition. As a result, the most promising candidates for potential application in nanomedicine were identified.

Probing protein nanopores with poly(ethylene glycol)s.

Neutral water-soluble poly(ethylene glycol)s (PEGs) have been extensively explored in protein nanopore research for the past several decades. The principal use of PEGs is to investigate the membrane protein ion channel physical characteristics and transport properties. In addition, protein nanopores are used to study polymer-protein interactions and polymer physicochemical properties. In this review, we focus on the biophysical studies on probing protein ion channels with PEGs, specifically on nanopore sizing by PEG partitioning. We discuss the fluctuation analysis of ion channel currents in response to the PEGs moving within their confined geometries. The advantages, limitations, and recent developments of the approach are also addressed.

Optimization of lipid nanoparticles for the delivery of nebulized therapeutic mRNA to the lungs.

Lipid nanoparticles (LNPs) for the efficient delivery of drugs need to be designed for the particular administration route and type of drug. Here we report the design of LNPs for the efficient delivery of therapeutic RNAs to the lung via nebulization. We optimized the composition, molar ratios and structure of LNPs made of lipids, neutral or cationic helper lipids and poly(ethylene glycol) (PEG) by evaluating the performance of LNPs belonging to six clusters occupying extremes in chemical space, and then pooling the lead clusters and expanding their diversity. We found that a low (high) molar ratio of PEG improves the performance of LNPs with neutral (cationic) helper lipids, an identified and optimal LNP for low-dose messenger RNA delivery. Nebulized delivery of an mRNA encoding a broadly neutralizing antibody targeting haemagglutinin via the optimized LNP protected mice from a lethal challenge of the H1N1 subtype of influenza A virus, and delivered mRNA more efficiently than LNPs previously optimized for systemic delivery. A cluster approach to LNP design may facilitate the optimization of LNPs for other administration routes and therapeutics.

Conformations, inter-molecular structure and hydrogen bond dynamics of neutral and cationic poly(vinyl amine) in aqueous solution

ABSTRACT Intermolecular structure, hydration and conformations of Poly(vinylamine) (PVAm) in neutral as well as protonated (cationic) condition as polyelectrolyte in dilute aqueous solution, were studied via single-chain atomistic molecular dynamics simulations in explicit solvent. A parametric study of atomic partial charges was carried out at different values of degree-of-ionisation (f) of the amine group. A modification of generic GROMOS force-field is developed. The unusual non-monotonic behaviour of radius-of-gyration with an increase in f is captured, in agreement with experimental results of intrinsic viscosity. Cooperative solvation of PVAm chain occurs with an increase in f as assisted by counter-ion condensation. Three different regimes of the variation of radius-of-gyration of PVAm with change in f are identified. Changes in polymer-water hydrogen bonding is not the dominant effect for the behaviour of chain-size variation. The non-monotonous expansion of PVAm is attributed to the complex interplay between hydrogen bonding and intermolecular structure of polymer chain, water and counter-ions, all of which provide a cooperative solvation of the chain. With an increase in f at the higher range, the formation of ion pairs produces salt-bridges and bends in the chain, as well as ion-pair–ion-pair repulsion extending the chain at complete ionisation.

Neutron investigation of interaction between anionic surfactant micelles and poly (ethylene glycol) polymer brush system

A polymer brush system of a neutral polymer poly (ethylene glycol) with a molecular weight of Mw = 20 kDa on silicon substrates in an aqueous medium was studied by the specular neutron reflectometry. Structural changes in the density profile of a polymer brush caused by the interaction of polymer chains with micelles of the anionic surfactant dodecylbenzenesulfonate acid were observed. The effect is shown to be related to the formation of molecular polymer-micelle associates in the bulk of the solution, which was previously studied by small-angle neutron scattering in a wide range of surfactant concentrations at various molecular weights of the polymer. The density of the dry polymer layer on the silicon substrate was additionally characterized by X-ray reflectometry and scanning atomic force microscopy.

Poly(catechol)s As Universal Electrode Materials for Advanced Organic Batteries

This decade has been witnessing the resurgence of redox-active polymer (RAP) based organic electrode materials in the quest of building large-scale, safe, economical, and sustainable electrochemical energy storage technologies (EESTs) after their brief silence. [1] Most of these RAPs mainly fall under the category of quinone, imide, organosulfur or radical polymers that have demonstrated admirable electrochemical performances. However, it is further necessary to design novel electrode materials with outstanding properties for the development of “next-generation” “high-performance” advanced organic batteries.Here, I present the macromolecular engineering of RAPs bearing catechol pendants of different functionality/composition that dictate their overall electrochemical performances in different battery technologies.Firstly, electrochemical performance of poly(catechol) cathodes in lithium-ion batteries will be presented. By tuning the pendant catechol structure, specific capacity of the homopolymer was boosted from 217 [for P(DA)] to 350 [for P(4VC)] mAh g‒1.[2] Furthermore, incorporation of cation conducting styrene sulfonates within the polymer chain in P(4VC-stat-LiSS) drastically improved the rate capability compared to P(4VC). Moreover, a voltage gain of +350 mV was demonstrated when catechol pendants were confined to an electron-withdrawing poly(ionic liquid) backbone, compared to the same redox groups groups in neutral poly(acrylamide) backbone.[3]Secondly, the application of poly(catechol) as organic cathodes for aqueous Zinc-ion batteries will be presented.[4] The Zn||P(4VC86-stat-SS14) cell in the optimized Zn(TFSI)2-H2O electrolyte simultaneously delivered high gravimetric capacity (324 mAh g‒1), high areal capacity (5.5 mAh cm‒2) at 1C, with remarkable capacity of 98 mAh g‒1 at 450C, extremely low capacity fading rate of 0.00035% per cycle over 48 000 cycles at 30 C rate and low temperature operativity (178 mAh g‒1 at –35 °C).Finally, all-polymer aqueous battery comprising poly(catechol) cathode and poly(imide) anode will be presented.[5] Interestingly, full cell exhibited tunable cell voltage depending on the salt used in the aqueous electrolyte, i.e., 0.58, 0.74, 0.89, and 0.95 V, respectively, when Li+, Zn2+, Al3+, and Li+/H+ were utilized as charge carriers. The full-cell delivered best rate performance (a sub-second charge/discharge) and cycling stability (80% capacity retention over 1000 cycles at 5 A g‒1) in Li+. Furthermore, maximum energy/power density of 80.6 Wh kganode+cathode ‒1/348 kW kganode+cathode ‒1 was achieved in Li+/H+, superior than most of the previously reported aqueous all–polymer batteries.Taking together, by the applicability of poly(catechol) as organic electrode material in different battery technologies, the following general conclusions can be drawn. They are quite universal- and accommodate reversibly numerous cations, ranging from H+, and Li+ to Al3+. This unprecedented approach is based on a simple catecholato–cation complex charge storage mechanism (n-type redox molecules). Development of such universal organic electrodes is particularly intriguing, and gaining popularity among the battery community due to the fact that it demands minimal electrode/device engineering efforts.

Efficient encapsulation of water soluble inorganic and organic actives in melamine formaldehyde based microcapsules for control release into an aqueous environment

Melamine formaldehyde (MF) is a versatile and widely used chemical cross-linking agent in microcapsule shells for the encapsulation of oil phases in an aqueous continuum. However, it has not been possible to form MF microcapsules with water soluble actives, to achieve sustained/no release in aqueous environment. Herein, 5 types of MF based microcapsules were designed and synthesised with 4 polymers, including neutral and polar poly(acrylamide-acrylic acid), anionically charged biocompatible shellac and ion exchange resin polystyrene sulfonate as well as a superhydrophobic polymer precursor octadecyltrichlorosilane, via an in situ polymerisation method. Potassium chloride and allura red (dye, Mw = 496.42 g·mol−1) were used as models of inorganic and organic water soluble actives with low molar mass, respectively, to study their size distributions, encapsulation efficiencies, payloads, morphologies and release rates in aqueous environment. The release rates ranged from complete release within 15 min to no release up to 1 month in aqueous environment.