Poly Sodium Research Articles

Carbon dioxide conversion into calcium carbonate nanoparticles using membrane gas absorption

Mineral carbonation in an aqueous solution is one of the practical strategies in carbon capture utilization and storage (CCUS). The wet carbonation can be further used to produce calcium carbonate nanoparticles with vast applications. Since the slow CO2 absorption affects the carbonation reaction, membrane gas absorption (MGA) with porous membranes was used in this study to enhance the mass transfer of CO2 gas into liquid absorbent for the carbonation of calcium-rich solution. The effects of sodium dodecyl sulphates (SDS) and poly(ethylene glycol) (PEG) on the properties of CaCO3 nanoparticles formed in wet carbonation were first studied. The calcite nanoparticles with particle size smaller than 25 nm were successfully produced, as proven in X-ray diffraction analysis and the transmission electron microscope images. Calcite nanoparticles with a BET surface area of 77.17 m2/g could adsorb 91.8 % of Congo red dye. The wet carbonation with surfactant-template was subsequently integrated with MGA. The pure CO2 absorption flux through the silanized polyvinylidene fluoride (PVDF)/TiO2 membrane enabled the formation of calcite nanoparticles in a calcium-rich solution containing a surfactant-template complex. The slow CO2 absorption flux of the commercial PVDF membrane with a hydrophobic surface cause failure to produce calcite with nano size.

Preparation, Characterization, Swelling Potential, and In-Vitro Evaluation of Sodium Poly(Styrene Sulfonate)-Based Hydrogels for Controlled Delivery of Ketorolac Tromethamine.

The objective of the current study work was to fabricate sodium poly(styrene sulfonate-co-poly acrylic acid) (SPSPAA) hydrogels by using a free radical co-polymerization method for controlled delivery of ketorolac tromethamine (KT). Polymer (sodium poly(styrene sulfonate) (SPS) polymerized with monomer acrylic acid (AA) in the presence of initiator ammonium peroxodisulfate (APS) and cross-linker N′,N′-Methylene bisacrylamide (MBA). Different combinations of polymer, cross-linker and monomer, were employed for development of polymeric hydrogels. Various studies such as sol-gel, drug loading, dynamic swelling, and drug release studies were carried out to know the sol and gel portion of SPSPAA, swelling behavior of hydrogels at different pH media (1.2 and 7.4), quantification of drug loaded by fabricated hydrogels, and amount release of KT at pH 1.2 and 7.4. Higher dynamic swelling was found at pH 7.4 compared to pH 1.2, and as a result, greater percent release of drug was perceived at pH 7.4. Thermal stability, crystallinity, confirmation of functional groups and development of a new polymeric system, and surface morphology were evaluated via Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), Powder X-ray Diffraction (PXRD), Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM) respectively. The results showed that the present work could be used as a potential candidate for controlled delivery of KT.

Production of magnetic sodium alginate polyelectrolyte nanospheres for lead ions removal from wastewater

Polyelectrolyte composite nanospheres are relatively new adsorbents which have attracted much attention for their efficient pollutant removal and reuse performance. A novel polyelectrolyte nanosphere with magnetic function (SA@AM) was synthesized via the electrostatic reaction between the polyanionic sodium alginate (SA) and the surface of a prepared terminal amino-based magnetic nanoparticles (AMs). SA@AM showed a size of 15–22 nm with 6.85 emu·g−1 of magnetization value, exhibiting a high adsorption capacity on Pb(II) ions representing a common heavy metal pollutant, with a maximum adsorption capacity of 105.8 mg g−1. The Langmuir isotherm adsorption fits the adsorption curve, indicating uniform adsorption of Pb(II) on the SA@AM surfaces. Repeated adsorption desorption experiments showed that the removal ratio of Pb(II) by SA@AM was more than 76%, illustrating improved regeneration performance. These results provide useful information for the production of bio-based green magnetic nano scale adsorption materials for environmental remediation applications.

N/O co-doped hierarchically porous carbon with three-dimensional conductive network for high-performance supercapacitors

Heteroatom doping is a significant modification of carbon materials for electrodes in storage device and co-doping has synergistic improvement effect. This work reports a N/O co-doped porous carbon (CPK800) from crosslinking sodium carboxymethyl cellulose and poly (m-phenylene diamine). The material characterization reveals its large specific surface area of 1501.3 m2 g−1 with optimum micro- and mesopore distribution, partially graphitized carbon and high N, O concentration. This carbon has 3D interconnected porous structure and internal conducting network providing rapid ion and electron transportation. Take these advantages, it exhibits high capacitance of 358 F/g at 1 A g−1, an excellent rate retention of 70.8% at a high current density of 20 A g−1, and superior cyclic stability of 97.8% capacitance retention after 10,000 cycles at 10 A g−1 as an electrode material in 3 M KOH electrolyte. Moreover, the assembled symmetric supercapacitor device (CPK800//CPK800) delivers a high energy density of 11.5 Wh kg−1 at a power density of 326.8 W kg−1 and still have energy density of 8.9 Wh kg−1 at a very high power density of 6.8 kW kg−1. The well-developed structure and outstanding electrochemical performance demonstrate the promising potential of CPK800 as electrode material for advanced energy storage devices.

Organic solvent resistant Kevlar nanofiber-based cation exchange membranes for electrodialysis applications

The development of organic solvent resistant ion exchange membranes (IEMs) with high ion conductivity is of significance for broader electrodialysis (ED) applications. In this work, a series of organic solvent resistant cation exchange membranes (CEMs) has been fabricated by splitting Kevlar fabrics into small and short nanofibers, followed by modifying with 4-amino-benzenesulfonic acid monosodium salt (ABS) and poly(4-styrenesulfonic acid-co-maleic acid) sodium salt (PSSMA) eater via amide condensation. By tuning the content of ABS, the as-prepared poly-p-phenylene terephthalamide sulfonated polymer (PAP) CEMs (PAP-CEMs) show high ion exchange capacities (up to 2.23 mmol⋅g−1), good electrochemical performance and desired capacity of cation/anion separation in ED. To evaluate the organic solvent resistance of as-prepared CEMs, PAP-CEMs were immersed in ethanol and acetone aqueous solutions for 48 h at room temperature, respectively. The investigation demonstrates that ED with the treated CEM (the optimized PAP-0.50 CEM) still exhibits high desalination efficiencies (81.2%, in 60% (Vethanol/Vwater) ethanol solution; 82.3%, in 60% (Vacetone/Vwater) acetone solution) and concentration efficiencies (57.4%, in 60% ethanol solution; 50.9%, in 60% acetone solution). As a result, it is believed that the study here highlights a design of simple route for the preparation of CEMs, which can be potentially applied in ED for organic solvent solution systems.

The macroscopic shape of assemblies formed from microparticles based on host\u2013guest interaction dependent on the guest content

Biological macroscopic assemblies have inspired researchers to utilize molecular recognition to develop smart materials in these decades. Recently, macroscopic self-assemblies based on molecular recognition have been realized using millimeter-scale hydrogel pieces possessing molecular recognition moieties. During the study on macroscopic self-assembly based on molecular recognition, we noticed that the shape of assemblies might be dependent on the host–guest pair. In this study, we were thus motivated to study the macroscopic shape of assemblies formed through host–guest interaction. We modified crosslinked poly(sodium acrylate) microparticles, i.e., superabsorbent polymer (SAP) microparticles, with β-cyclodextrin (βCD) and adamantyl (Ad) residues (βCD(x)-SAP and Ad(y)-SAP microparticles, respectively, where x and y denote the mol% contents of βCD and Ad residues). Then, we studied the self-assembly behavior of βCD(x)-SAP and Ad(y)-SAP microparticles through the complexation of βCD with Ad residues. There was a threshold of the βCD content in βCD(x)-SAP microparticles for assembly formation between x = 22.3 and 26.7. On the other hand, the shape of assemblies was dependent on the Ad content, y; More elongated assemblies were formed at a higher y. This may be because, at a higher y, small clusters formed in an early stage can stick together even upon collisions at a single contact point to form elongated aggregates, whereas, at a smaller y, small clusters stick together only upon collisions at multiple contact points to give rather circular assemblies. On the basis of these observations, the shape of assembly formed from microparticles can be controlled by varying y.

Sustainable Strategy Based on Induced Precipitation for the Purification of Phycobiliproteins

Phycobiliproteins are fluorescent proteins mainly produced by red macroalgae and cyanobacteria. These proteins, essential to the survival of these organisms, find application in many fields of interest, from medical, pharmaceutical, and cosmetic to food and textile industries. The biggest obstacle to their use is the lack of simple environmental and economical sustainable methodologies to obtain these proteins with high purity. In this work, a new purification process is proposed based on the induced precipitation of the target proteins followed by ultrafiltration. Purities of 89.5% of both phycobiliproteins and 87.3% of R-phycoerythrin were achieved using ammonium sulfate and poly(acrylic acid) sodium salts as precipitation agents (followed by an ultrafiltration step), while maintaining high recovery yields and protein structure stability. Environmental analysis performed to evaluate the proposed process shows that the carbon footprint for the proposed process is much lower than that reported for alternative methodology, and the economic analysis reveals the cost-effective character associated to its high performance. This work is a step toward more sustainable and effective methodologies/processes with high industrial potential.

Nanosheets of copolymerized ionic liquid-based polyelectrolyte complexes regulated at oil–water interface and their emulsification capability

The emulsification by polyelectrolyte complexes is easy to handle, and could be considered as an effective strategy for introducing functional materials to liquid–liquid interfaces, but the related studies are still insufficient. Herein, a kind of copolymerized ionic liquid (PIL-co-PVIm) which is synthesized from 1-vinyl-3-ethylimidazolium bromide and 1-vinylimidazole, are used as polycation to form polyelectrolyte complexes type Pickering emulsifiers with sodium alginate, poly(sodium 4-styrenesulfonate) and poly (acrylic acid) sodium salt respectively as polyanion. For toluene-water emulsion systems and hydrophobic ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIm]PF6)-water system, the polyelectrolyte complexes formed by PIL-co-PVIm and sodium alginate or poly (sodium 4-styrenesulfonate) showed best emulsification capability. The emulsions stabilized by the polyelectrolyte complexes at stoichiometric ratio are relatively less stable compared to non-stoichiometric complexes, while PIL-co-PVIm without complexation has no emulsification capability. The polyelectrolyte complexes based on homopolymerized PIL give an unsatisfied emulsification capability, while the emulsification performance could be remarkably improved by copolymerizing ionic liquids with the uncharged comonomer, but excessive contents of the uncharged unit make the polyelectrolyte complexes less interface active. The sheet-like PECs are formed in aqueous dispersions, and their thickness is remarkably reduced at oil–water interface after emulsification, approximately ranging from 200 nm to 10 nm by manipulating the polyanion.

Preparation of electroconductive film based on self-assembled aminothiophene/poly(γ-glutamate) nanoparticles and its application in biosensor

An electroconductive nanoparticles (NPs) film consisting of sodium poly(γ-glutamate) (γ-PGANa) and 3,4-diaminothiophene dihydrochloride (DATh) was simply prepared through macromolecular self-assembly and electropolymerization methods. Firstly, the γ-PGANa and the DATh underwent a complexation to form DATh/γ-PGANa composites through the electrostatic interaction; the DATh/γ-PGANa composites were then self-assembled into DATh/γ-PGANa NPs through decreasing the pH value in aqueous solution. Next, an electroconductive NPs film was formed on the surface of a gold electrode by casting the DATh/γ-PGANa NPs and subsequently electropolymerizing the DATh. Last, horseradish peroxidase and Nafion were cast onto the NPs film to obtain an enzymatic biosensor for H2O2 detection. The electroconductive DATh/γ-PGANa NPs film endowed the biosensor with high sensitivity. Under the optimal conditions, the prepared biosensor showed a linear range from 1 × 10−11 to 1 × 10−4 mol·L−1 with a detection limit of 3 × 10−12 mol·L−1 for H2O2 detection. The biosensor can retain its detection performance for 4 weeks. The response currents of the biosensor changed little after adding the interferent into the analyte. The standard deviation of the response between different biosensors did not exceed 2.5%.

Design and in vivo evaluation of alginate-based pH-sensing electrospun wound dressing containing anthocyanins

In this study, a pH-sensing electrospun mat containing purple cabbage (PC) (Brassica oleracea) anthocyanins was developed for wound dressing application. The pH-sensing electrospun mat was prepared from sodium alginate (Alg) and poly (vinyl alcohol) (PVA) via electrospinning. PC anthocyanins were embedded into the electrospun mat with the addition of PC extract into the Alg/PVA electrospun solution. The characterization studies were conducted by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), water contact angle (WCA) and thickness measurements. The halochromic behavior of the pH-sensing Alg/PVA/PC electrospun mat was elucidated via UV–Vis spectrophotometric analyses and color measurements obtained from quantitative color data. In vivo performance of the pH-sensing mat was evaluated by animal studies. The electrospun mat was successfully used to monitor pH changes of an open wound. In addition, wound healing efficacy of the electrospun mat was compared with a commercial wound dressing. The results revealed that a wound dressing benefiting from halochromic properties of the anthocyanins besides wound healing efficacy of Alg was successfully developed. The pH-sensing Alg/PVA/PC electrospun mat has a usage potential for wound dressing applications especially for monitoring wound status on real-time during healing period.

Carboplatin-loaded surface modified-PLGA nanoparticles confer sustained inhibitory effect against retinoblastoma cell in vitro.

To investigate the antiproliferative effect of carboplatin-loaded surface-modified poly(lactide-co-glycolide) on retinoblastoma cells. Carboplatin-loaded poly(lactide-co-glycolide) with or without sodium alginate surface modification was prepared using sodium alginate-poly(lactide-co-glycolide) and poly(lactide-co-glycolide). The zeta potential and carboplatin release behavior were investigated. The cellular uptake of the released drug was observed in the retinoblastoma cell line Y79. The inhibitory effect of carboplatin-loaded nanoparticles against the Y79 cell line was evaluated using methyl thiazolyl tetrazolium assay and western blot. Native carboplatin and void nanoparticles without carboplatin loading were used as controls. The zeta potential was -(26.1 ± 3.1) mV for carboplatin-loaded poly(lactide-co-glycolide) and-(43.1 ± 8.1) mV for carboplatin-loaded sodium alginate-poly(lactide-co-glycolide). The burst release percentages of carboplatin-loaded poly(lactide-co-glycolide) and sodium alginate-poly(lactide-co-glycolide) were (40.0% ± 8.2%) and (18.9% ± 4.3%) at 24 hours, respectively. A significant difference was identified regarding drug release between carboplatin-loaded sodium alginate-poly(lactide-co-glycolide) and carboplatin-loaded poly(lactide-co-glycolide). Fluorescence detection revealed that intense uptake of carboplatin into the cytoplasm of the Y79 cell line that was exposed to carboplatin-loaded sodium alginate-poly(lactide-co-glycolide). Carboplatin-loaded poly(lactide-co-glycolide) or sodium alginate-poly(lactide-co-glycolide) exposure inhibited proliferating cell nuclear antigen expression in Y79 cells on day 3. Extension of exposure to day 5 revealed that the sodium alginate-poly(lactide-co-glycolide) surface modification was superior to that of poly(lactide-co-glycolide) in terms of proliferating cell nuclear antigen inhibition. The cell viability test using methyl thiazolyl tetrazolium revealed a similar inhibitory effect. Furthermore, the carboplatin-loaded nanoparticles of lower concentration inhibited cell viability more strongly than native carboplatin of higher concentration in methyl thiazolyl tetrazolium assay. Carboplatin-loaded sodium alginate-poly(lactide-co-glycolide) inhibited retinoblastoma cell proliferation with superior effect as compared with poly(lactide-co-glycolide) and native carboplatin. Sodium alginate surface modification offers a potential strategy for the sustained carboplatin release system.

Layer-by-layer coated hybrid nanoparticles with pH-sensitivity for drug delivery to treat acute lung infection

Bacteria-induced acute lung infection (ALI) is a severe burden to human health, which could cause acute respiratory distress syndrome (ARDS) and kill the patient rapidly. Therefore, it is of great significance to develop effective nanomedicine and therapeutic approach to eliminate the invading bacteria in the lung and manage ALI. In this study, we design a layer-by-layer (LbL) liposome-polymer hybrid nanoparticle (HNP) with a pH-triggered drug release profile to deliver antibiotics for the eradication of bacteria to treat ALI. The liposome is prepared by the lipid film hydration method with a homogenous hydrodynamic diameter and low polydispersity index (PDI). The antibiotic spectinomycin is efficiently loaded into the liposomal core through the pH-gradient method. The pH-sensitive polycationic polymer poly(β-amino ester) (PBAE) and polyanionic sodium alginate (NaAIg) layers are decorated on the surface of liposome in sequence via electrostatic interaction, resulting in spectinomycin-loaded layer-by-layer hybrid nanoparticles (denoted as Spe@HNPs) which have reasonable particle size, high stability, prolonged circulation time, and pH-triggered drug release profile. The in vitro results demonstrate that Spe@HNPs can efficiently induce the death of bacteria with low minimum inhibitory concentration (MIC) against Staphylococcus aureus (S. aureus) and drug-resistant MRSA BAA40 strains. The in vivo results reveal that Spe@HNPs can eradicate the invading MRSA BAA40 with improved antimicrobial efficacy and low side-effect for ALI treatment. This study not only reports a promising nanomedicine but also provides an effective method to prepare nanoplatforms for drug delivery and controlled release.

Counter‐Intuitive Structural Instability Aroused by Transition Metal Migration in Polyanionic Sodium Ion Host

AbstractThe structure of polyanionic materials is conventionally known to be free of transition metal migration and structurally stable when storing/releasing sodium ions. Herein, the observation of enhanced cycling stability of a typical polyanionic cathode, Na3VCr(PO4)3 (NVCP) at lower temperature (−15 °C vs 30 °C), triggers the exploration of its structural origins with a surprising finding that the migratable nature of vanadium in NVCP leads to detrimental structural degradation of the polyanionic host upon cycling. The correlation between long range and short range structural change associated with this atomic migration is established via a strong combination of various in situ/ex situ characterization tools, revealing the essential V–to–Na1 site migration. Such transition metal migration is effectively suppressed when V atoms are pinned to their original position in the lattice by lowering the temperature. More importantly and practically, a room temperature‐based deep sodiation strategy is further developed to recover the structure. This work challenges the long‐standing assumption of the stability of the polyanionic framework structure and calls for urgent attention to the structural understanding of the NVCP system as well as strategy development for property enhancement.

Controlled Release of Phosphorus from Superabsorbent Phosphate-Bound Alginate-Graft-Polyacrylamide: Resistance to Soil Cations and Release Mechanism.

Two controlled-released fertilizers of phosphorylated alginate grafted with polyacrylamide (P-Alg-g-PAM) were synthesized. Monoammonium phosphate (MAP) and diammonium phosphate (DAP) were reacted with a matrix of sodium alginate (Alg) and poly(vinyl alcohol) (PVA). The phosphorylated matrix was then grafted with acrylamide. The obtained fertilizer materials showed excellent water absorbance. The controlled-release behavior of phosphorylated alginate grafted with polyacrylamide (P-Alg-g-PAM) was investigated at normal pH and 25 °C. The fertilizer materials exhibited release of phosphorus up to 77% for the MAP sample and up to 57% for the DAP sample till the forty fifth day of the application at pH 7 and 25 °C. More importantly, when the release experiments were conducted in calcium chloride medium, the fertilizers were able to release phosphorus efficiently with slight decrease until the forty fifth day of the application, suggesting that the presence of Alg in the fertilizer formulation may help in extending the duration for which phosphorus is available to the plant.

Study of Polyaniline/Poly(Sodium 4-Styrenesulfonate) Composite Deposits Using an Electrochemical Quartz Crystal Microbalance for the Modification of a Commercial Anion Exchange Membrane.

One of the intended applications for the modification of ion exchange membranes with polyaniline (PAni) is to use it as a matrix to include chemical species that confer a special property such as resistance to fouling or ion selectivity. In particular, the inclusion of polyelectrolyte molecules into the PAni matrix appears to be the way to modulate these properties of selective membranes. Therefore, it must be clearly understood how the polyelectrolyte is incorporated into the matrix of polyaniline. Among the results obtained in this paper using poly(sodium 4-styrenesulfonate) (PSS) and an electrochemical quartz crystal microbalance, the amount of polyelectrolyte incorporated into PAni is found to be proportional to the PSS concentration in solution if its value is between 0 and 20 mM, while it reaches a maximum value when the PSS in solution is greater than 20 mM. When the anion exchange membranes are modified with these composite deposits, the transport number of chloride was found to decrease progressively (when the PSS concentration in solution is between 0 and 20 mM) to reach a practically constant value when a concentration of PSS greater than 20 mM was used.

Design and Characterization of Sodium Alginate and Poly(vinyl) Alcohol Hydrogels for Enhanced Skin Delivery of Quercetin.

Nature has led to the discovery of biopolymers with noteworthy pharmaceutical applications. Blended biopolymers have demonstrated promising characteristics when compared with their individual counterparts. Sodium alginate (SA) is a marine polymer that has demonstrated the ability to form hydrogels, an interesting property for the development of cutaneous formulations. Predicting the good performance of blended biopolymers, a novel series of hybrid hydrogels based on SA and poly(vinyl) alcohol (PVA) were prepared. Quercetin, a natural polyphenolic flavonoid commonly found in fruits and vegetables, is widely known for its strong anti-inflammatory and antioxidant activity, thus with potential applications against melanoma, dermatitis, psoriasis, and skin ageing. Here, hydrogels were produced at different ratios of SA and PVA. The surface morphology, structure, interaction of polymers, the capacity to absorb water and the entrapment efficiency of quercetin were evaluated for the blended hydrogels. Targeting the cutaneous application of the formulations, the rheological properties of all unloaded and quercetin-loaded hydrogels revealed pseudoplastic behavior, evidence of non-thixotropy, good resistance to deformation, and profile maintenance with temperatures ranging from 20 °C up to 40 °C. The incorporation of quercetin in the hydrogel retained its antioxidant activity, confirmed by radical scavenging assays (ABTS and DPPH). The permeability of quercetin through the skin showed different penetration/permeation profiles according to the hydrogel’s blend. This behavior will allow the selection of SA-PVA at 2/1 ratio for a local and prolonged skin effect, making the use of these hydrogels a good solution to consider for the treatment of skin ageing and inflammation.

Preparation and photoelectric properties of Bi2WO6-CdS hybrid nanocrystals

The poly sodium polyacrylate (PAANa) latex particles containing hybrid nanocrystals of bismuth tungstate-cadmium sulfide (Bi2WO6-CdS) were prepared by the combination process of inverse miniemulsion, absorption, and solvothermal treatment. The Bi2WO6-PAANa latex particles and CdS-PAANa latex particles were prepared by inverse miniemulsion polymerization for formation of CdS based on Bi2WO6 (Bi2WO6/CdS) and Bi2WO6 based on CdS (CdS/Bi2WO6) hybrid nanocrystals, respectively. The effects of dropping strategies in absorption and solvothermal treatment condition on the size, their distribution and the morphologies of Bi2WO6/CdS-PAANa and CdS/Bi2WO6-PAANa latex particles were investigated. The dropping in order was better than simultaneous dropping in absorption process. The clustered Bi2WO6/rod-like CdS and the punctate CdS/punctate Bi2WO6 hybrid nanocrystals could be grown under the same solvothermal conditions. The influences of cadmium sulfate/sodium sulfide (CdSO4/NaS) millimolar number on the grain size and the morphologies of Bi2WO6/CdS hybrid nanocrystals were investigated. With the CdSO4/NaS millimolar number increase, the grain size of CdS rod-like and Bi2WO6 cluster gradually increased due to oriented attachment and Ostwald ripening, respectively. The Bi2WO6-CdS hybrid nanocrystals will perform the excellent photoelectric properties.

Probing surface interactions of underwater oleophobic polyelectrolyte multilayers

In the present work, the interaction mechanism of specific polyelectrolyte multilayers (PEMs), fabricated by layer-by-layer deposition of polydiallyldimethylammonium chloride (PDDA) and poly(sodium 4-styrenesulfonate) (PSS), is studied using atomic force microscopy. The underwater oil-repellency of PSS-capped PEMs was further explored by measuring the interaction forces between tetradecane droplets and PEMs-coated silica substrates under various salinities. The force curves were analyzed following the Stokes–Reynolds–Young–Laplace theoretical model. Desirable consistency was achieved between the experimental and theoretical calculations at low NaCl concentrations (0.1 mM and 1 mM); however, underestimation of the attractive force was found as the NaCl concentration increases to moderate (10 mM) and high (100 mM) levels. Discrepancy analyses and incorporated features toward a reduced surface charge density were considered based on the previous findings of the orientation of anionic benzenesulfonate moieties (Liu et al. in Angew Chem Int Ed 54(16):4851–4856, 2015. https://doi.org/10.1002/anie.201411992). Short-range steric hindrance interactions were further introduced to simulate “brush” effect stemming from nanoscale surface roughness. It is demonstrated in our work that the PSS-capped PEMs remains a stable underwater lipophobicity against high salinity, which renders it potential application in surface wetting modification and anti-fouling.

Poly(acrylic acid) capped iron oxide nanoparticles via ligand exchange with antibacterial properties for biofilm applications

Biofilm infections pose a rising threat to public health due to its existing protective shield, which preventing biocide penetration. Here, the oleate-capped iron oxide nanoparticles (OIONPs) were synthesized by the high-temperature method first; after then, the poly(acrylic acid)-capped iron oxide nanoparticles (PIONPs) were obtained via a ligand exchange reaction between OIONPs and sodium poly(acrylic acid). The physicochemical properties of PIONPs were evaluated by Fourier-transform Infrared Spectroscopy (FT-IR), X-ray Diffraction (XRD), Scanning Transmission Electron Microscopy (STEM), Dynamic Light Scattering (DLS), and zeta potential. The FT-IR analysis confirmed the successful ligand exchange on the surface of iron oxide nanoparticles. STEM images displayed that the prepared PIONPs were monodisperse spherical nanoparticles. The PIONPs were stable in ultrapure water and could be kept for 5 weeks without aggregation. Next, Cell Counting Kit-8 (CCK-8) assay and fluorescent images confirmed the excellent cytocompatibility of PIONPs, while the iron concentration of PIONPs was in the range of 5∼120 mg/L. Finally, PIONPs exhibited efficient antibacterial activity against E. coli and S. aureus, and Staphylococcus aureus subsp. aureus Rosenbach (SASAR) biofilm could be destroyed by treating PIONPs under alternating current (AC) applied field conditions.

Electrochemical Synthesis of an Organic Thermoelectric Power Generator.

Energy harvesting through residual heat is considered one of the most promising ways to power wearable devices. In this work, thermoelectric textiles were prepared by coating the fabrics, first with multiple-wall carbon nanotubes (MWCNTs) by using the layer-by-layer technique and second with poly(3,4-ethylenedioxythiophene) (PEDOT) deposited by electrochemical polymerization. Sodium deoxycholate and poly(diallyldimethylammonium chloride) were used as stabilizers to prepare the aqueous dispersions of MWCNTs. The electrochemical deposition of PEDOT on the MWCNT-coated fabric was carried out in a three-electrode electrochemical cell. The polymerization of PEDOT on the fabric increased the electrical conductivity by ten orders of magnitude (through the plane), establishing an excellent path for electric transport across the fabrics. In addition, the fibers showed a Seebeck coefficient of 14.3 μV K-1, which is characteristic of highly doped PEDOT. As a proof of concept, several thermoelectric modules were made with different elements based on the coated acrylic and cotton fabrics. The best generator made of 30 thermoelectric elements using acrylic fabrics exhibited an output power of 0.9 μW with a temperature difference of 31 K.