Simple Poly Research Articles

Salvinia natans-Based Hierarchical Structures for Solar Thermal Clean Water Production from High-Salinity Wastewater.

Biomaterial-based solar-driven evaporation has great potential for wastewater treatment and seawater desalination with a high energy conversion and utilization efficiency. However, technology gaps still exist for effectively and directly applying multiscale structures and intrinsic water transport channels of natural materials to enhance high-efficiency photothermal evaporation. In this study, a high-performance biomass-derived photothermal evaporative material was obtained using Salvinia natans, a common aquatic floating plant, together with simple poly(m-phenylenediamine) oxidation modification, building a hybrid biomass evaporator. With advantageous natural features of adequate water transport, microscale-nanoscale hierarchical structures, effective water activation, and antisalt-fouling function, the hybrid biomass evaporator achieves a high evaporation rate of 2.24 kg m-2 h-1 under one sun radiation (1 kW m-2). In addition, modified Salvinia natans also demonstrate certain ability to remove heavy metals during the photothermal evaporation of wastewater. This work offers a new perspective on the synthesis of an environmentally friendly and cost-effective solar-driven evaporator material, which has the advantages of low cost, simple process, and high photothermal conversion efficiency, and can be widely applied to seawater desalination and the treatment of wastewater with high salt concentrations.

Reversible Chemical Modification of Antibody Effector Function Mitigates Unwanted Systemic Immune Activation.

Antibody effector functions including antibody-dependent cellular cytotoxicity (ADCC) and phagocytosis (ADCP) are mediated through the interaction of the antibody Fc region with Fcγ receptors present on immune cells. Several approaches have been used to modulate antibody Fc-Fcγ interactions with the goal of driving an effective antitumor immune response, including Fc point mutations and glycan modifications. However, robust antibody-Fcγ engagement and immune cell binding of Fc-enhanced antibodies in the periphery can lead to the unwanted induction of systemic cytokine release and other dose-limiting infusion-related reactions. Creating a balance between effective engagement of Fcγ receptors that can induce antitumor activity without incurring systemic immune activation is an ongoing challenge in the field of antibody and immuno-oncology therapeutics. Herein, we describe a method for the reversible chemical modulation of antibody-Fcγ interactions using simple poly(ethylene glycol) (PEG) linkers conjugated to antibody interchain disulfides with maleimide attachments. This method enables dosing of a therapeutic with muted Fcγ engagement that is restored in vivo in a time-dependent manner. The technology was applied to an effector function enhanced agonist CD40 antibody, SEA-CD40, and experiments demonstrate significant reductions in Fc-induced immune activation in vitro and in mice and nonhuman primates despite showing retained efficacy and improved pharmacokinetics compared to the parent antibody. We foresee that this simple, modular system can be rapidly applied to antibodies that suffer from systemic immune activation due to peripheral FcγR binding immediately upon infusion.

Development of simple and effective poly methyl orange modified pencil graphite electrode for the voltammentric investigation of aminotriazole in presence of 2,4-dichlorophenoxyacetic acid

The growing health risks linked to environmental exposure to mutagenic, teratogenic, and carcinogenic herbicides have sparked a significant interest in developing rapid and cost-effective detection technologies for accurate quantification of these compounds. Therefore, current research concerns a selective and sensitive electrochemical determination of Aminotriazole (AMT) using an inexpensive modified polymerized methyl orange pencil graphite electrode (PMO/PGE). The PMO/PGE and bare pencil graphite electrode (BPGE) have been characterized through various analytical techniques such as scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX) and electrochemical impedance spectroscopy (EIS). The electro-oxidation behavior of AMT was investigated by utilizing various methodologies including cyclic voltammetry (CV), linear sweep voltammetry (LSV) and differential pulse voltammetry (DPV) in 0.1 M phosphate buffer solution (PBS) of pH 7.0. AMT exhibits a significant increase in anodic peak current of 7.15 µA at PMO/PGE compared to BPGE. The effect of electro-kinetic factors involved in the electro-oxidation of AMT, such as the heterogeneous rate constant, scan rate, surface concentration, pH and the number of electrons and protons transferred were resolved. The electro-oxidation reaction involves two protons and two electrons, according to the electrochemical analysis of AMT at PMO/PGE. The number of electrons involved in a redox reaction is often determined experimentally, and it is a key parameter in understanding the reaction mechanism. Under the investigational conditions, the anodic peak current of the analyte is directly proportional to its concentration in the range 1.0 – 13.0 µM with the limit of detection (LOD) being 1.24 × 10−8 M. The developed modifiedsensor has got good reproducibility, sensitivity, selectivity and stability, and it could be successfully validated for the detection of AMT present in real samples.

Highly sensitive and selective electrochemical sensor for simultaneous determination of gallic acid, theophylline and caffeine using poly(l-proline) decorated carbon nanotubes in biological and food samples

In this work, a novel, simple and reproducible poly(l-proline)/functionalized multi-walled carbon nanotube composite on glassy carbon electrode (poly(PRO)-MWCNTs/GCE) was developed as an electrochemical sensor for the simultaneous determination of gallic acid (GA), theophylline (TP) and caffeine (CAF) by differential pulse voltammetry (DPV).The sensing platform was optimized by experimental design and response surface methodology, using various factors affecting polymerization and detection, such as electropolymerization time and potential, and pH, respectively. As a result, the dispersion conditions were the mixing of 1.78 mg MWCNTs with 1.00 mL l-proline solution to 4.14 mg mL−1 (in SDBS 0.5%), followed by 21 min of sonication with electropolymerization by 16 cyclic scans. In addition, the final analysis was performed at a pH of 3.00 and prior accumulation at 0.350 V for 40 s.The electrochemical behavior of GA, TP and CAF on the optimized sensor was investigated. As a result, the electrode preserves and synergistically combines the properties of each modifier. This new electrochemical sensor showed superior electrocatalytic properties for the oxidation of GA, TP and CAF, which significantly improved the sensitivity of the three compounds.Under the optimized experimental conditions, the detection limits achieved by S/N were 0.03, 0.04 and 0.11 μmol L−1 for GA, TP and CAF, respectively. The analysis of real samples was successfully performed in human breast milk, tea, infusion of yerba mate, coffee, Coca-Cola zero and energy drink, showing good recoveries, ranged between 87 and 108%. The proposed sensor also showed good selectivity, repeatability and reproducibility, indicating feasibility and reliability.This is the first time that the l-proline monomer is used as a dispersant for MWCNTs and as a precursor for the in-situ polymerization of the proline polymer. Previously, the electropolymerizations were carried out with the monomer in solution rather than as an exfoliant of MWCNTs, where the polymer is electrosynthesized between MWCNTs rather than on them. In this way, the large specific surface area and strong adsorption ability of the nanomaterial are enhanced, and the ability to promote electron transfer reaction is increased, which provides enough effective reaction sites.

CLT-seq as a universal homopolymer-sequencing concept reveals poly(A)-tail-tuned ncRNA regulation.

Dynamic tuning of the poly(A) tail is a crucial mechanism for controlling translation and stability of eukaryotic mRNA. Achieving a comprehensive understanding of how this regulation occurs requires unbiased abundance quantification of poly(A)-tail transcripts and simple poly(A)-length measurement using high-throughput sequencing platforms. Current methods have limitations due to complicated setups and elaborate library preparation plans. To address this, we introduce central limit theorem (CLT)-managed RNA-seq (CLT-seq), a simple and straightforward homopolymer-sequencing method. In CLT-seq, an anchor-free oligo(dT) primer rapidly binds to and unbinds from anywhere along the poly(A) tail string, leading to position-directed reverse transcription with equal probability. The CLT mechanism enables the synthesized poly(T) lengths, which correspond to the templated segment of the poly(A) tail, to distribute normally. Based on a well-fitted pseudogaussian-derived poly(A)-poly(T) conversion model, the actual poly(A)-tail profile is reconstructed from the acquired poly(T)-length profile through matrix operations. CLT-seq follows a simple procedure without requiring RNA-related pre-treatment, enrichment or selection, and the CLT-shortened poly(T) stretches are more compatible with existing sequencing platforms. This proof-of-concept approach facilitates direct homopolymer base-calling and features unbiased RNA-seq. Therefore, CLT-seq provides unbiased, robust and cost-efficient transcriptome-wide poly(A)-tail profiling. We demonstrate that CLT-seq on the most common Illumina platform delivers reliable poly(A)-tail profiling at a transcriptome-wide scale in human cellular contexts. We find that the poly(A)-tail-tuned ncRNA regulation undergoes a dynamic, complex process similar to mRNA regulation. Overall, CLT-seq offers a simplified, effective and economical approach to investigate poly(A)-tail regulation, with potential implications for understanding gene expression and identifying therapeutic targets.

A Simple Poly(Vinyl Sulfonate) Coating for All‐Purpose, Self‐Cleaning Applications: Molecular Packing Density–Defined Surface Superhydrophilicity

AbstractIn this study, poly(vinyl sulfonate) (PVS)–capped surfaces are constructed on the polyelectrolyte multilayers (PEMs) of poly(diallyldimethylammonium chloride) and poly(styrene sulfonate) via electrostatic assembly. The water wetting behavior on the resulting PVS‐capped PEMs is meticulously correlated with the number of surface sulfonate groups with the aid of sum frequency generation spectroscopy and quartz crystal microbalance. It is found that when the molecular packing density of surface sulfonate groups is adjusted to be comparable to the maximal packing density of spheres in two dimensions (≈0.9), the PVS capping is able to effectively adsorb water molecules from the surrounding to form hydrogen‐bonded networks, which not only promote complete surface wetting by water in air but also diminish surface affinity to adhesion of ice, oil and wax deposited atop. As a result, the PVS‐capped PEMs are able to fulfil all the self‐cleaning functions proposed for superhydrophilic surfaces including anti‐fogging, anti‐icing, anti‐grease, anti‐smudge, anti‐graffiti, and anti‐wax. After being coated with the self‐cleaning PVS‐capped PEMs, conventional stainless steel meshes are able to perform oil‐water separation without prior water wetting.

Electrochemical detection and quantification of catechol based on a simple and sensitive poly(riboflavin) modified carbon nanotube paste electrode

In the present research work, selective and sensitive catechol (CT) detection and quantification were shown in the presence of resorcinol (RS) in 0.2 M phosphate buffer (PB) solution by preparing a low-cost, simple, and green carbon nanotube paste electrode (CNTPE) surface activated with electropolymerized riboflavin (PRF). The morphological, conductivity, and electrochemical features of the modified electrode (PRFMCNTPE) and bare carbon nanotube paste electrode (BCNTPE) materials were analyzed using electrochemical impedance spectroscopy (EIS), field emission scanning electron microscopy (FE-SEM), cyclic voltammetry (CV), and differential pulse voltammetry (DPV). The PRF-activated electrode displays outstanding sensitivity, stability, selectivity, reproducibility, and repeatability for the redox feature of CT with improved electrochemical current and declined electrochemical potential compared to BCNTPE. The peak currents of CT are correlated to the different CT concentrations (CV method: 6.0–60.0 μM & DPV method: 0.5–7.0 μM), and the obtained detection limit (DL) and quantification limit (QL) are found to be 0.025 μM and 0.085 μM (CV method) and 0.0039 μM and 0.0132 μM (DPV method), respectively. The prepared PRFMCNTPE material was advantageous for the examination of CT in environmentally important tap water sample as a real-time application.

Sensitive electrochemical determination of riboflavin at simple and low-cost poly (valine) modified graphite paste electrode

• A modest, responsive, low-cost, and green electrochemically polymerised valine modified graphite paste electrode was developed. • FE-SEM, EI, and CV measurements are used for electrode materials characterisation. • Riboflavin electrochemical redox action was analysed using polymerised valine modified graphite paste electrode. • prepared electrochemical sensor provides a lower limit of detection with fine sensitivity and reproducibility. • The modified electrochemical sensor gives acceptable recoveries for riboflavin in medicinal sample. A sensitive electrochemical analysis of riboflavin (RFN) was done in 0.1 M phosphate buffer solution (PTBS) by constructing a modest and green electrochemically polymerised (EP) valine (VLN) modified graphite paste electrode (GPE). The electrochemical, morphological, resistive, and conductive characteristics of modified electrode (EP(VLN)MGPE) and bare graphite paste electrode (BGPE) surfaces were clarified through cyclic voltammetry (CV), field emission scanning electron microscopy (FE-SEM), and Electrochemical impedance (EI) methods. The EP(VLN) initiated electrode surface parades excellent sensitivity, steadiness, repeatability, and reproducibility for the redox action of RFN with enhanced peak currents as associated to BGPE. The oxidation peak currents of RFN are improved with increased concentrations of RFN in the range from 2.0 µM to 40.0 µM and the attained limit of detection (LOD) and limit of quantification (LOQ) are found to be about 28.69×10 -8 M and 95.66×10 -8 M, respectively. The prepared EP(VLN)MGPE was beneficial for the quantitative and qualitative investigation of RFN in medicinal samples.

18.55% Efficiency Polymer Solar Cells Based on a Small Molecule Acceptor with Alkylthienyl Outer Side Chains and a Low-Cost Polymer Donor PTQ10

18.55% Efficiency Polymer Solar Cells Based on a Small Molecule Acceptor with Alkylthienyl Outer Side Chains and a Low-Cost Polymer Donor PTQ10

Unraveling the Photovoltaic, Mechanical, and Microstructural Properties and Their Correlations in Simple Poly(3‐pentylthiophene) Solar Cells

The power conversion efficiency of polythiophene organic solar cells is constantly refreshed. Despite the renewed device efficiency, very few efforts have been devoted to understanding how the type of electron acceptor alters the photovoltaic and mechanical properties of these low-cost solar cells. Herein, the authors conduct a thorough investigation of photovoltaic and mechanical characteristics of a simple yet less-explored polythiophene, namely poly(3-pentylthiophene) (P3PT), in three different types of organic solar cells, where ZY-4Cl, PC71 BM, and N2200 are employed as three representative acceptors, respectively. Compared with the reference poly(3-hexylthiophene) (P3HT)-based solar cells, P3PT-based devices, all perform more efficiently. Particularly, the P3PT:ZY-4Cl blend exhibits the highest efficiency (ca. 10%) among the six combinations and outperforms the prior top-performance system P3HT:ZY-4Cl. Furthermore, the blend films based on N2200 exhibit a high crack-onset strain of ∼38% on average, which is approximately 15- and 17-times higher than those of ZY-4Cl and PC71 BM, respectively. The microstructural origins for the above difference are well elucidated by detailed grazing incidence X-ray scattering and microscopy analysis. This work not only underlines the potential of P3PT in prolific solar cell research but also demonstrates the superior tensile properties of polythiophene-based all-polymer blends for the preparation of stretchable solar cells.

PEGylated and zwitterated silica nanoparticles as doxorubicin carriers applied in a breast cancer cell line: Effects on protein corona formation

Nanomaterials exposed to biological fluids form protein coronas on their surfaces, changing their original properties. Surface functionalization with nonfouling moieties is a strategy to synthesize silica nanoparticles (SiNPs) with the ability to hinder protein corona formation. We report a simple poly(ethylene glycol) (PEG) and zwitterionic (ZWT)-based surface modification method to prepare doxorubicin-loaded SiNPs to avoid protein corona formation in breast cancer cells. Drug-loaded SiNPs were characterized in terms of particle size, charge, and drug loading content. A comparison of the stability between PEG and ZWT on SiNP surfaces was performed at 25 °C and 37 °C in a high salt solution using turbidimetry. At 37 °C, the PEGylated SiNPs showed aggregation. In contrast, under the same conditions, zwitterated SiNPs did not show aggregation. Both PEG and ZWTSiNP savoided protein adsorption in the presence of increasing concentrations of bovine serum albumin (BSA). In vitro cell experiments demonstrated that both functionalization approaches (SiNPs-PEG and SiNPs-ZWT) improved biocompatibility in the breast cancer cell line MCF-7compared to SiNPs. The antitumour effects of doxorubicin-loaded SiNPs were evaluated via red neutral cell uptake and annexin V assays, and the results demonstrated that surface functionalization plays an important role in the cytotoxic profile of these systems, with SiNPs-DOX-PEG and SiNPs-DOX-ZWT exhibiting a superior cytotoxic effect compared to SiNPs-DOX.

Direct growth of boronate based shikimic acid imprinted polymer on porous substrate surface: A stable membrane for specific molecular separation

Identifiable separation of shikimic acid (SA) compound is important for antiviral drug production. Current separation methods used for shikimic acid remain unsatisfied due to lack of specificity that can accurately and instantly anchor the target molecular from interfering impurities. Membrane separation seems to be feasible with the advantages of low energy consumption and operating convenience. Herein, benefiting from the characteristic cis-diol group in SA, a smart and simple poly(vinylidene fluoride) (PVDF) based molecular imprinted membrane (MIM) is synthesized by using 4-vinylbenzeneboronic acid as functional monomer to form prepolymers with SA. The resulting SA-imprinted boronate affinity molecular imprinted membranes (SA-imprinted-BAMIMs) show enhanced adsorption capacity (51.99 mg g−1) compared with reported material. It should be noted that the formation of boronate ester bond between functional monomer and SA can help to specifically capture the target, and the release of combined SA on the membrane becomes easy due to the reversible bind characteristic of boronate ester under different pH condition. Moreover, SA-imprinted-BAMIMs exhibit acceptable stability after ultrasonic for 5 h and satisfactory regeneration performance after 8 cycles of adsorption–desorption experiments (93.02%). This convenient MIMs display great potential in the following work on rapid and specific separation of SA for commercial synthesis of antiviral.

Tailoring Therapeutic Responses via Engineering Microenvironments with a Novel Synthetic Fluid Gel.

This study reports the first fully synthetic fluid gel (SyMGels) using a simple poly(ethylene glycol) polymer. Fluid gels are an interesting class of materials: structured during gelation via shear-confinement to form microparticulate suspensions, through a bottom-up approach. Structuring in this way, when compared to first forming a gel and subsequently breaking it down, results in the formation of a particulate dispersion with particles "grown" in the shear flow. Resultantly, systems form a complex microstructure, where gelled particles concentrate remaining non-gelled polymer within the continuous phase, creating an amorphous-like interstitial phase. As such, these materials demonstrate mechanical characteristics typical of colloidal glasses, presenting solid-like behaviors at rest with defined yielding; likely through intrinsic particle-particle and particle-polymer interactions. To date, fluid gels have been fabricated using polysaccharides with relatively complex chemistries, making further modifications challenging. SyMGels are easily functionalised, using simple click-chemistry. This chemical flexibility, allows the creation of microenvironments with discrete biological decoration. Cellular control is demonstrated using MSC (mesenchymal stem cells)/chondrocytes and enables the regulation of key biomarkers such as aggrecan and SOX9. These potential therapeutic platforms demonstrate an important advancement in the biomaterial field, underpinning the mechanisms which drive their mechanical properties, and providing a versatile delivery system for advanced therapeutics.

Conformation of poly(ethylene glycol) in aqueous cholinium amino acid hybrid solvents

HypothesisHybrid solvents based on cholinium amino acid ionic liquids ([Ch][AA] ILs) mixed with water are environmentally benign solvents with low toxicity. [Ch][AA] ILs are used in biomass pretreatment processes to dissolve targeted (macro)molecules such as lignin from lingnocellulose. Understanding how [Ch][AA] ILs dissolve polymers is therefore of great interest for the rational design of ILs towards industrial application. Variation of the IL anion and the water concentration are hypothesised to change the solvent properties of [Ch][AA] hybrid solvents. Therefore, we probe the solvent quality of [Ch][AA] aqueous solutions with different anions (glycinate, prolinate and argininate) and water concentration for the simple model solute poly(ethylene glycol) (PEG). ExperimentsPartial phase diagrams were produced to probe the salting-out effect of [Ch][AA] ILs towards PEG (Mw = 38 kDa). Small-angle neutron scattering experiments of deuterated PEG in hydrogenous [Ch][AA] aqueous solutions were performed to determine the polymer radius of gyration at infinite dilution (Rg,0) via Zimm-plots. Polymer concentration dependent apparent Rg values were obtained fitting an excluded volume polymer model onto the scattering data. Blends of hydrogenous and deuterated PEG under zero average contrast conditions were analysed to probe Rg at high polymer concentrations. FindingsHydrogen bond capacity of the anion is key to the salting-out effect of [Ch][AA] ILs on PEG. Rg,0 depends on anion species and water concentration. At IL:water = 1:30 (mole:mole) and 37 °C, cholinium argininate and cholinium glycinate are close to theta solvents while cholinium prolinate and dilute cholinium argininate (IL:water = 1:100) are between theta and good solvents.

Bis-Imino-Acenaphthenequinone Based Covalent Organic Framework for Lithium-Ion Battery Applications

Covalent organic frameworks (COF) are crystalline and porous, 2 or 3-dimensional structures. The precise structure tunability and high porosity make these materials interesting for various applications like gas adsorption, proton conduction, energy storage etc. Further, COFs synthesized from π-conjugated systems with short interlayer distances could exhibit electron conduction properties[1]. This property makes these materials promising candidates for secondary batteries as well. In this regard, there were reports on imine functional COFs synthesized by condensation of aldehyde and amine[2]. These COFs exhibit uniform porosity and a stable cycling performance as anodes in lithium ion and Sodium ion batteries. Further, the high porosity, the precise structure tunability and possibility of various functional groups presents a unique opportunity to produce heteroatom doped, highly porous and semi crystalline carbon upon pyrolysis. Owing to the drawbacks of graphite in fast charge and discharge, much effort is being directed towards synthesizing heteroatom doped carbonaceous materials among which, N-doped carbon shows promising results. In this regard, various strategies like pyrolysis of carbonaceous material with doping agents like urea, melamine etc., is extensively studied[3,4] However, these N-doped carbon materials suffer with lack of good conductivity and lack of precise control over the amount of heteroatom doping. In this regard, we present the synthesis of novel bis imino acenaphthoquinone (BIAN)-melamine based covalent organic framework and its bifold applications as 1) an organic alternative to graphite anode in lithium-ion battery and 2) a precursor material for synthesis of N-doped carbon with good rate capability.BIAN-melamine covalent organic framework (BM-COF) was synthesized by simple poly condensation method. Further, BM-COF was pyrolyzed at 800 ℃ to obtain N-doped carbon (Py-BM COF). Both the materials BM-COF and Py-BM-COF were systematically characterized and used to prepare anodes for Li ion batteries. The electrodes were coated using active material (BM-COF/Py-BM-COF), PVDF (binder), and acetylene black (conductive additive) in the weight ratios of 70:15:15 in case of BM COF as active material and 80:10:10 for Py-BM-COF as active material. Coin cells of 2025 type were fabricated using lithium as counter/reference electrode, 1 M LiPF6 in 1:1 EC: DEC as electrolyte, and the coated electrodes as anodes. Cyclic voltammetry was performed at various scan rates in a potential window of 0.01 V to 3.00 V for BM-COF anodes and 0.01 to 2.10 V for Py-BM-COF anodes. Galvanostatic charge discharge studies were carried out in the same potential windows at various current densities and the cycle life of the material was evaluated.The formation of imine bond in COF was confirmed by FT-IR and X-ray photoelectron spectroscopies. The pore size and surface area were evaluated by nitrogen adsorption-desorption studies. The surface area was found to be 31.6 m2/g and the pore size was found to be 1.7 nm. The XRD spectrum showed sharp peak at 13º corresponding to a d-spacing of 0.68 nm indicating high crystallinity and a stacked structure due to π interactions. The nitrogen content in Py-BM COF was found to be 13 atomic percentage using EDX. The XPS spectra showed the presence of pyridinic, pyrrolic and quaternary nitrogen. TEM micrographs showed macro pores. Li-ion battery with BM-COF anode material showed a reversible capacity of 317 mAh/g at 50 mA/g current density which was higher than that of graphite at 50 mA/g current density and the Py-BM-COF anode showed a capacity of 260 mAh/g at 1 A/g current with a capacity retention over 85% after 500 cycles (Figure-1). We report the synthesis and bifold applications of BIAN-melamine COF. The reported organic material and the N-doped carbon exhibits good electrochemical performance. These results present the material as interesting alternative to graphite anodic material.

Mechanisms by which different polar fractions of dissolved organic matter affect sorption of the herbicide MCPA in ferralsol

Exogenous dissolved organic matter (DOM) modifies the sorption of 4-chloro-2-methylphenoxyacetic acid (MCPA, a polar herbicide) in soil. However, how the chemodiversity and diverse fractions of DOM affect MCPA sorption is still unknown. Here, DOM was extracted from compost and rice straw; the structure–activity correlations between DOM chemodiversity and their effects on MCPA sorption were investigated by redundancy analysis. Moreover, the mechanism involved was explored by spectroscopic techniques, microbeam and modeling. DOM mainly affected MCPA sorption by altering soil surface properties and MCPA complexed form. Hydrophobic neutral (HON) and acid insoluble matter (AIM) were the fractions of DOM that most inhibited MCPA sorption through soil pore blockage, and were related to the humic-like substances with high aromaticity and large molecular weight. The hydrophobic acid fraction (HOA) only showed an intermediate inhibition on the sorption, although the largest competitive sorption occurred. This was because HOA contained abundant aromatic acid and polar groups with moderate polarity. Thus, the reduced effect caused by competitive sorption was partly compensated by the greatest co-sorption by HOA. The hydrophilic matter (HIM) had the weakest inhibition on MCPA sorption, because this fraction was rich in simple sugars, poly- and oligosaccharides, but lacked aryl groups. The results will aid in the risk assessments and prevention of MCPA in DOM-introduced soil.

A simple and low-cost poly (dl-phenylalanine) modified carbon sensor for the improved electrochemical analysis of Riboflavin

The current study reports on the electroanalysis of Riboflavin (RF) on the surface of a poly dl -phenylalanine modified carbon paste sensor (PDLPAMCPS). The developed sensor caused a noticeable electrocatalytic action for the redox activity of RF in a phosphate buffer solution (PBS) of pH 6.5. This analysis was evaluated using differential pulse voltammetry (DPV) and cyclic voltammetry (CV) techniques. The active surface of the functioning sensor exposes well developed anodic peak with prominent electron transfer. PDLPAMCPS shows distinctive and improved DPV and CV peaks for RF with and without the presence of organic dyes and dopamine (DA). The impact of the solution pH, scan rate, accumulation potential and concentration on RF at PDLPAMCPS were studied. A vibrant linear growth was observed between the oxidation peak current and the RF concentration in the range of 6.0 μM–30.0 μM, which provides a lower limit of detection (LOD) of 92 nM with excellent sensitivity. The proposed method and sensor were applied for the assessment of RF in medicine sample as an analytical application with fine recoveries and low LOD. • A simple and low-cost carbon sensor was designed using poly ( dl -Phenylalanine) for the sensing of Riboflavin. • Prepared sensor was characterized by CV, DPV, EIS and FE-SEM analysis. • Equipped sensor shows high sensitivity, selectivity and lower LOD of 92 nM towards Riboflavin detection. • Interference effect on prepared sensor for Riboflavin was studied.

Solution Self-Assembly of Chalcogen-Bonding Polymer Partners.

Chalcogen bonding is regarded as a form of noncovalent interaction; however, harnessing chalcogen bonds to drive macromolecular self-assembly remains unexplored. Here we report two classes of chalcogen-bonding partner polymers and their unique self-assembly behaviors in THF/H2O solution. Using simple poly(4-vinylphenyl chalcogenide) (P4VCh, Ch = Te or Se) as the donor polymer and poly(ethylene oxide)-block-poly(4-vinylpyridine N-oxide) (PEO-b-P4VO) as the acceptor polymer, they can form donor-acceptor noncovalent complexes and further aggregate into tubular and spherical assemblies through interchain Te···O and Se···O chalcogen-chalcogen interactions. The small distinction in binding affinity of chalcogen bonds can dictate the assembly of different geometries. Moreover, mixing the strong and weak chalcogen-bonding pairs in various ratios can allow us to obtain ergodic phase evolution with tunable dimensionality and morphology.

PEG-b-PLGA Nanoparticles Loaded with Geraniin from Phyllanthus Watsonii Extract as a Phytochemical Delivery Model

The study outlined a standardized double emulsion method for simple poly(ethylene glycol)-block-poly(lactic-co-glycolic acid) (PEG-b-PLGA) nanoparticle (NP) synthesis. The PEG-b-PLGA NP was also used for entrapment of geraniin as a simple model system for phytochemical delivery. PEG-b-PLGA NPs were prepared using the double emulsion method. The yields and particle sizes of PEG-b-PLGA NPs obtained with and without encapsulation of geraniin were 57.6% and 134.20 ± 1.45 nm and 66.7% and 102.70 ± 12.36 nm, respectively. High-performance liquid chromatography of geraniin that was extracted from Phyllanthus watsonii was detected at 64 min. Geraniin burst release began at 40 min and fully released at 3 h. PEG-b-PLGA NP was non-cytotoxic, while cytotoxicity of geraniin was dose dependant towards normal human epithelial colon cells, CCD 841 CoN cells.

Adhesion between oppositely charged polyelectrolytes in salt solution

AbstractThe adhesion at the aqueous interface between a polyacid hydrogel and a grafted polycation layer (brush) is shown to be reversible on the addition of sodium chloride, which screens the charges on the gel and brush. Furthermore, it is shown that a double‐network (DN) hydrogel both exhibits adhesive failure and stronger adhesion with the brush than a simple poly(methacrylic acid) (PMAA) hydrogel, which undergoes cohesive failure on detachment. The adhesive force at the hydrogel–brush interface significantly increases after adding dilute salt solution (of 0.001 M). Once the concentration of salt solution is raised above 0.05 M, both the adhesive force and work done in detaching both single‐network and DN hydrogels from the brush surface are notably reduced. This result confirms that reversible adhesion between a hydrogel and polymer brush in salt solutions is possible, although a DN gel is required for adhesive failure.