MyMedR

Displaying publications 41 - 60 of 829 in total

Abstract:

Sort:

Tetracycline removal in granulation: Influence of extracellular polymers substances, structure, and metabolic function of microbial community

Yan L, Chen W, Wang C, Liu S, Liu C, Yu L, et al.

Chemosphere, 2022 Feb;288(Pt 2):132510.
PMID: 34627823 DOI: 10.1016/j.chemosphere.2021.132510

Tetracycline is a potentially hazardous residual antibiotic detected in various sewages. High concentration (mg/L) of tetracycline is found in pharmaceutical/hospital wastewater and wastewater derived from livestock and poultry. So far, only antibiotics in μg/L level have been reported in granulation of aerobic sludge during wastewater treatment, but its effects in high concentration are rarely reported. In this study, the influence of tetracycline in high concentration (∼2 mg/L) on the formation of granular sludge, structure, and metabolic function of the microbial community during the granulation of aerobic sludge was investigated to improve the understanding of the aerobic granular sludge formation under high-level of tetracycline. The role of extracellular polymers substances (EPSs) derived from granular sludge in the granulation and tetracycline removal process was also investigated, showing that tetracycline improved the relative hydrophobicity, flocculability and protein/polysaccharide ratio of EPSs, accelerating the granulation of sludge. Succession of microbial communities occurred during the domestication of functional bacteria present in the sludge and was accompanied with regulation of metabolic function. The addition of tetracycline lead to an increase of tetracycline-degrading bacteria or antibiotic resistance genus. Those findings provide new perspectives of the influence of tetracycline on aerobic sludge granulation and the removal mechanism of tetracycline.

Matched MeSH terms: Polymers
Advanced nanocellulose-based gas barrier materials: Present status and prospects

Wu Y, Liang Y, Mei C, Cai L, Nadda A, Le QV, et al.

Chemosphere, 2022 Jan;286(Pt 3):131891.
PMID: 34416587 DOI: 10.1016/j.chemosphere.2021.131891

Nanocellulose based gas barrier materials have become an increasingly important subject, since it is a widespread environmentally friendly natural polymer. Previous studies have shown that super-high gas barrier can be achieved with pure and hierarchical nanocellulose films fabricated through simple suspension or layer-by-layer technique either by itself or incorporating with other polymers or nanoparticles. Improved gas barrier properties were observed for nanocellulose-reinforced composites, where nanocellulose partially impermeable nanoparticles decreased gas permeability effectively. However, for nanocellulose-based materials, the higher gas barrier performance is jeopardized by water absorption and shape deformation under high humidity conditions which is a challenge for maintaining properties in material applications. Thus, numerous investigations have been done to solve the problem of water absorption in nanocellulose-based materials. In this literature review, gas barrier properties of pure, layer-by-layer and composite nanocellulose films are investigated. The possible theoretical gas barrier mechanisms are described, and the prospects for nanocellulose-based materials are discussed.

Matched MeSH terms: Polymers
Vibrational studies of flexible solid polymer electrolyte based on PCL-EC incorporated with proton conducting NH4SCN

Woo HJ, Arof AK

Spectrochim Acta A Mol Biomol Spectrosc, 2016 May 15;161:44-51.
PMID: 26945998 DOI: 10.1016/j.saa.2016.02.034

A flexible solid polymer electrolyte (SPE) system based on poly(ε-caprolactone) (PCL), a FDA approved non-toxic and biodegradable material in the effort to lower environmental impact was prepared. Ammonium thiocyanate (NH4SCN) and ethylene carbonate (EC) were incorporated as the source of charge carriers and plasticizing agent, respectively. When 50wt.% of ethylene carbonate (EC) was added to PCL-NH4SCN system, the conductivity increased by two orders from of 3.94×10(-7)Scm(-1) to 3.82×10(-5)Scm(-1). Molecular vibrational analysis via infrared spectroscopy had been carried out to study the interaction between EC, PCL and NH4SCN. The relative percentage of free ions, ion pairs and ion aggregates was calculated quantitatively by deconvoluting the SCN(-) stretching mode (2030-2090cm(-1)). This study provides fundamental insight on how EC influences the free ion dissociation rate and ion mobility. The findings are also in good agreement to conductivity, differential scanning calorimetry and X-ray diffraction results. High dielectric constant value (89.8) of EC had made it an effective ion dissociation agent to dissociate both ion pairs and ion aggregates, thus contributing to higher number density of free ions. The incorporation of EC had made the polymer chains more flexible in expanding amorphous domain. This will facilitate the coupling synergy between ionic motion and polymer segmental motion. Possible new pathway through EC-NH4(+) complex sites for ions to migrate with shorter distance has been anticipated. This implies an easier ion migration route from one complex site to another.

Matched MeSH terms: Polymers
Vaginal drug delivery: strategies and concerns in polymeric nanoparticle development

Wong TW, Dhanawat M, Rathbone MJ

Expert Opin Drug Deliv, 2014 Sep;11(9):1419-34.
PMID: 24960192 DOI: 10.1517/17425247.2014.924499

Vaginal infection is widespread and > 80% of females encounter such infections during their lives. Topical treatment and prevention of vaginal infection allows direct therapeutic action, reduced drug doses and adverse effects, convenient administration and improved compliance. The advent of nanotechnology results in the use of nanoparticulate vehicle to control drug release, to enhance dosage form mucoadhesive properties and vaginal retention, and to promote mucus and epithelium permeation for both extracellular and intracellular drug delivery.

Matched MeSH terms: Polymers/chemistry
Drug release property of chitosan-pectinate beads and its changes under the influence of microwave

Wong TW, Nurjaya S

Eur J Pharm Biopharm, 2008 May;69(1):176-88.
PMID: 17980563

The effects of microwave irradiation on the drug release property of pectinate beads loaded internally with chitosan (chitosan-pectinate beads) were investigated against the pectinate beads and beads coacervated with chitosan externally (pectinate-chitosonium beads). These beads were prepared by an extrusion method using sodium diclofenac as the model water-soluble drug. The beads were subjected to microwave irradiation at 80 W for 5, 10, 21 and 40 min. The profiles of drug dissolution, drug content, drug-polymer interaction and polymer-polymer interaction were determined by drug dissolution testing, drug content assay, drug adsorption study, differential scanning calorimetry (DSC) and Fourier transform infra-red spectroscopy (FTIR) techniques. Treatment of pectinate beads by microwave did not lead to a decrease, but an increase in the extent of drug released at 4h of dissolution owing to reduced pectin-pectin interaction via the CO moiety of polymer. In addition, the extent of drug released from the pectinate beads could not be reduced merely through the coacervation of pectinate matrix with chitosan. The reduction in the extent of drug released from the pectinate-chitosonium beads required the treatment of these beads by microwave, following an increase in drug-polymer and polymer-polymer interaction in the matrix. The extent of drug released from the pectinate beads was reduced through incorporating chitosan directly into the interior of pectinate matrix, owing to drug-chitosan adsorption. Nonetheless, the treatment of chitosan-pectinate matrix by microwave brought about an increase in the extent of drug released unlike those of pectinate-chitosonium beads. Apparently, the loading of chitosan into the interior of pectinate matrix could effectively retard the drug release without subjecting the beads to the treatment of microwave. The microwave was merely essential to reduce the release of drug from pectinate beads when the chitosan was introduced to the pectinate matrix by means of coacervation. Under the influences of microwave, the drug release property of beads made of pectin and chitosan was mainly modulated via the CH, OH and NH moieties of polymers and drug, with CH functional group purported to retard while OH and NH moieties purported to enhance the drug released from the matrix.

Matched MeSH terms: Polymers/chemistry
Alginate graft copolymers and alginate-co-excipient physical mixture in oral drug delivery

Wong TW

J Pharm Pharmacol, 2011 Dec;63(12):1497-512.
PMID: 22060280 DOI: 10.1111/j.2042-7158.2011.01347.x

Use of alginate graft copolymers in oral drug delivery reduces dosage form manufacture complexity with reference to mixing or coating processes. It is deemed to give constant or approximately steady weight ratio of alginate to covalently attached co-excipient in copolymers, thereby leading to controllable matrix processing and drug release. This review describes various grafting approaches and their outcome on oral drug release behaviour of alginate graft copolymeric matrices. It examines drug release modulation mechanism of alginate graft copolymers against that of co-excipients in non-grafted formulations.

Matched MeSH terms: Polymers
Fulltext Crystal structure and Hirshfeld surface analysis of a chalcone derivative: (E)-3-(4-fluoro-phen-yl)-1-(4-nitro-phen-yl)prop-2-en-1-one

Wong QA, Chia TS, Kwong HC, Chidan Kumar CS, Quah CK, Arafath MA

Acta Crystallogr E Crystallogr Commun, 2019 Jan 01;75(Pt 1):53-57.
PMID: 30713733 DOI: 10.1107/S2056989018017450

The mol-ecular structure of the title chalcone derivative, C15H10FNO3, is nearly planar and the mol-ecule adopts a trans configuration with respect to the C=C double bond. The nitro group is nearly coplanar with the attached benzene ring, which is nearly parallel to the second benzene ring. In the crystal, mol-ecules are connected by pairs of weak inter-molecular C-H⋯O hydrogen bonds into inversion dimers. The dimers are further linked by another C-H⋯O hydrogen bond and a C-H⋯F hydrogen bond into sheets parallel to (104). π-π inter-actions occur between the sheets, with a centroid-centroid distance of 3.8860 (11) Å. Hirshfeld surface analysis was used to investigate and qu-antify the inter-molecular inter-actions.

Matched MeSH terms: Polymers
Fulltext Curcumin Nanoformulations for Colorectal Cancer: A Review

Wong KE, Ngai SC, Chan KG, Lee LH, Goh BH, Chuah LH

Front Pharmacol, 2019;10:152.
PMID: 30890933 DOI: 10.3389/fphar.2019.00152

Colorectal cancer (CRC) is the third most prevalent form of cancer, after lung cancer and breast cancer, with the second highest death incidence. Over the years, natural compounds have been explored as an alternative to conventional cancer therapies such as surgery, radiotherapy, and chemotherapy. Curcumin, an active constituent of turmeric has been associated with various health benefits. It has gained much attention as an anticancer agent due to its ability to regulate multiple cell signaling pathways, including NF-κB, STAT3, activated protein-1 (AP-1), epidermal growth response-1 (Egr-1), and p53, which are crucial in cancer development and progression. Nevertheless, the clinical application of curcumin is greatly restricted because of its low water solubility, poor oral absorption, and rapid metabolism. These issues have led to the development of curcumin nanoformulations to overcome the limitations of the compound. Nanotechnology-based delivery systems have been widely used in improving the delivery of poorly-water soluble drugs. Besides, these systems also come with the added benefits of possible cellular targeting and improvement in cellular uptake. An ideal improved formulation should display a greater anticancer activity compared to free curcumin, and at the same time be non-toxic to the normal cells. In this review, we focus on the design and development of various nanoformulations to deliver curcumin for use in CRC such as liposomes, micelles, polymer nanoparticles, nanogels, cyclodextrin complexes, solid lipid nanoparticles (SLN), phytosomes, and gold nanoparticles. We also discuss the current pre-clinical and clinical evidences of curcumin nanoformulations in CRC therapy, analyse the research gap, and address the future direction of this research area.

Matched MeSH terms: Polymers
Formulation and evaluation of controlled release Eudragit buccal patches

Wong CF, Yuen KH, Peh KK

Int J Pharm, 1999 Feb 01;178(1):11-22.
PMID: 10205621

Controlled release buccal patches were fabricated using Eudragit NE40D and studied. Various bioadhesive polymers, namely hydroxypropylmethyl cellulose, sodium carboxymethyl cellulose and Carbopol of different grades, were incorporated into the patches, to modify their bioadhesive properties as well as the rate of drug release, using metoprolol tartrate as the model drug. The in-vitro drug release was determined using the USP 23 dissolution test apparatus 5 with slight modification, while the bioadhesive properties were evaluated using texture analyzer equipment with chicken pouch as the model tissue. The incorporation of hydrophilic polymers was found to affect the drug release as well as enhance the bioadhesiveness. Although high viscosity polymers can enhance the bioadhesiveness of the patches, they also tend to cause non-homogeneous distribution of the polymers and drug, resulting in non-predictable drug-release rates. Of the various bioadhesive polymers studied, Cekol 700 appeared to be most satisfactory in terms of modifying the drug release and enhancement of the bioadhesive properties.

Matched MeSH terms: Polymers/chemistry*
Mechanical properties of natural fibre reinforced PVC composites: a review

Wirawan R, Zainudin E, Sapuan S

Sains Malaysiana, 2009;38.

Poly (vinyl chloride), which is commonly abbreviated as PVC, is widely used due to it being inexpensive, durable, and flexible. As a hard thermoplastic, PVC is used in the applications such as in building materials pipe and plumbing. The factors that should be considered in using PVC is safety and environmental issues. Mixing PVC with natural fibres is an interesting alternative. The main challenge in the research on natural fibre/polymer composites is the poor compatibility between the fibres and the matrix because this will affect their bonding strength. During the mixing with PVC, some natural fibres may acts as reinforcing materials while other natural fibres only act as filler, which contribute less to mechanical strength improvement. However, generally natural fibres also give positive outcome to the stiffness of the composites while decreasing the density.

Matched MeSH terms: Polymers
FT-IR studies on interactions among components in hexanoyl chitosan-based polymer electrolytes

Winie T, Arof AK

Spectrochim Acta A Mol Biomol Spectrosc, 2006 Mar 1;63(3):677-84.
PMID: 16157506

Fourier transform infrared (FT-IR) spectroscopic studies have been undertaken to investigate the interactions among components in a system of hexanoyl chitosan-lithium trifluoromethanesulfonate (LiCF(3)SO(3))-diethyl carbonate (DEC)/ethylene carbonate (EC). LiCF(3)SO(3) interacts with the hexanoyl chitosan to form a hexanoyl chitosan-salt complex that results in the shifting of the N(COR)(2), CONHR and OCOR bands to lower wavenumbers. Interactions between EC and DEC with LiCF(3)SO(3) has been noted and discussed. Evidence of interaction between EC and DEC has been obtained experimentally. Studies on polymer-plasticizer spectra suggested that there is no interaction between the polymer host and plasticizers. Competition between plasticizer and polymer on associating with Li(+) ions was observed from the spectral data for gel polymer electrolytes. The obtained spectroscopic data has been correlated with the conductivity performance of hexanoyl chitosan-based polymer electrolytes.

Matched MeSH terms: Polymers/chemistry*
Polymer-based or Polymer-free Stents in Patients at High Bleeding Risk

Windecker S, Latib A, Kedhi E, Kirtane AJ, Kandzari DE, Mehran R, et al.

N Engl J Med, 2020 03 26;382(13):1208-1218.
PMID: 32050061 DOI: 10.1056/NEJMoa1910021

BACKGROUND: Polymer-free drug-coated stents provide superior clinical outcomes to bare-metal stents in patients at high bleeding risk who undergo percutaneous coronary intervention (PCI) and are treated with 1 month of dual antiplatelet therapy. Data on the use of polymer-based drug-eluting stents, as compared with polymer-free drug-coated stents, in such patients are limited.
METHODS: In an international, randomized, single-blind trial, we compared polymer-based zotarolimus-eluting stents with polymer-free umirolimus-coated stents in patients at high bleeding risk. After PCI, patients were treated with 1 month of dual antiplatelet therapy, followed by single antiplatelet therapy. The primary outcome was a safety composite of death from cardiac causes, myocardial infarction, or stent thrombosis at 1 year. The principal secondary outcome was target-lesion failure, an effectiveness composite of death from cardiac causes, target-vessel myocardial infarction, or clinically indicated target-lesion revascularization. Both outcomes were powered for noninferiority.
RESULTS: A total of 1996 patients at high bleeding risk were randomly assigned in a 1:1 ratio to receive zotarolimus-eluting stents (1003 patients) or polymer-free drug-coated stents (993 patients). At 1 year, the primary outcome was observed in 169 of 988 patients (17.1%) in the zotarolimus-eluting stent group and in 164 of 969 (16.9%) in the polymer-free drug-coated stent group (risk difference, 0.2 percentage points; upper boundary of the one-sided 97.5% confidence interval [CI], 3.5; noninferiority margin, 4.1; P = 0.01 for noninferiority). The principal secondary outcome was observed in 174 patients (17.6%) in the zotarolimus-eluting stent group and in 169 (17.4%) in the polymer-free drug-coated stent group (risk difference, 0.2 percentage points; upper boundary of the one-sided 97.5% CI, 3.5; noninferiority margin, 4.4; P = 0.007 for noninferiority).
CONCLUSIONS: Among patients at high bleeding risk who received 1 month of dual antiplatelet therapy after PCI, use of polymer-based zotarolimus-eluting stents was noninferior to use of polymer-free drug-coated stents with regard to safety and effectiveness composite outcomes. (Funded by Medtronic; ONYX ONE ClinicalTrials.gov number, NCT03344653.).

Matched MeSH terms: Polymers*
Fulltext Investigation of Deacetylation Treatment at Different Temperature for Chitosan Extraction from Shrimp Shell Waste

William, W., Newati Wid

Borneo Journal of Medical Sciences, 2018;12(101):65-0.
MyJurnal

Disposal of shrimp shell waste is gradually increasing throughout the years due to the constant growing of cultured shrimp production at the local area which in turn increases the bio-waste of shrimp shell. Shrimp shell waste contains valuable components such as protein and chitin. Chitin can be found at the outer surface of shrimp shell, while chitosan can be derived from chitin. Chitosan is a valuable natural polymer as it holds major potentials for industrial applications. However, the poor quality of chitosan has restricted its potential in applications and this is due to the difficulties in maintaining its degree of deacetylation, solubility, and ash content. Hence, several factors such as the temperature for deacetylation treatment, concentration of alkaline solution, ratio of chitin to alkaline solution, and few other factors are important to produce a good quality of chitosan.

Matched MeSH terms: Polymers
Fulltext Facile Approaches of Polymeric Face Masks Reuse and Reinforcements for Micro-Aerosol Droplets and Viruses Filtration: A Review

Wibisono Y, Fadila CR, Saiful S, Bilad MR

Polymers (Basel), 2020 Oct 28;12(11).
PMID: 33126730 DOI: 10.3390/polym12112516

Since the widespread of severe acute respiratory syndrome of coronavirus 2 (SARS-CoV-2) disease, the utilization of face masks has become omnipresent all over the world. Face masks are believed to contribute to an adequate protection against respiratory infections spread through micro-droplets among the infected person to non-infected others. However, due to the very high demands of face masks, especially the N95-type mask typically worn by medical workers, the public faces a shortage of face masks. Many papers have been published recently that focus on developing new and facile techniques to reuse and reinforce commercially available face masks. For instance, the N95 mask uses a polymer-based (membrane) filter inside, and the filter membrane can be replaced if needed. Another polymer sputtering technique by using a simple cotton candy machine could provide a cheap and robust solution for face mask fabrication. This review discuss the novel approaches of face mask reuse and reinforcement specifically by using membrane-based technology. Tuning the polymeric properties of face masks to enhance filterability and virus inactivity is crucial for future investigation.

Matched MeSH terms: Polymers
Fulltext Free-Radical Photopolymerization of Acrylonitrile Grafted onto Epoxidized Natural Rubber

Whba R, Su'ait MS, Tian Khoon L, Ibrahim S, Mohamed NS, Ahmad A

Polymers (Basel), 2021 Feb 23;13(4).
PMID: 33672185 DOI: 10.3390/polym13040660

The exploitation of epoxidized natural rubber (ENR) in electrochemical applications is approaching its limits because of its poor thermo-mechanical properties. These properties could be improved by chemical and/or physical modification, including grafting and/or crosslinking techniques. In this work, acrylonitrile (ACN) has been successfully grafted onto ENR- 25 by a radical photopolymerization technique. The effect of (ACN to ENR) mole ratios on chemical structure and interaction, thermo-mechanical behaviour and that related to the viscoelastic properties of the polymer was investigated. The existence of the -C≡N functional group at the end-product of ACN-g-ENR is confirmed by infrared (FT-IR) and nuclear magnetic resonance (NMR) analyses. An enhanced grafting efficiency (~57%) was obtained after ACN was grafted onto the isoprene unit of ENR- 25 and showing a significant improvement in thermal stability and dielectric properties. The viscoelastic behaviour of the sample analysis showed an increase of storage modulus up to 150 × 103 MPa and the temperature of glass transition (Tg) was between -40 and 10 °C. The loss modulus, relaxation process, and tan delta were also described. Overall, the ACN-g-ENR shows a distinctive improvement in characteristics compared to ENR and can be widely used in many applications where natural rubber is used but improved thermal and mechanical properties are required. Likewise, it may also be used in electronic applications, for example, as a polymer electrolyte in batteries or supercapacitor.

Matched MeSH terms: Polymers
Fulltext Release of bisphenol a from polycarbonate and polyethylene terephthalate drinking water bottles under different storage conditions and its associated health risk

Wen Min Yun, Yu Bin Ho, Eugenie Sin Sing Tan, Vivien How

Malaysian Journal of Medicine and Health Sciences, 2018;14(102):1-9.
MyJurnal

Bisphenol A (BPA) is a controversial plastics ingredient used mainly in the production of polycarbonate plastics (PC) and epoxy resins that widely used nowadays in food and drink packaging. Even though BPA is not involved in polyethylene terephthalate (PET) manufacturing, recent study had reported the present of BPA in PET water bottle. This study was conducted to investigate effects storage conditions on release of BPA from PC and PET bottled water as well as to assess health risks associated with consumption. Methods: Solid phase extraction (SPE) was used to extract the samples, followed by analysis using ultra high performance liquid chromatography with fluorescence detector (UHPLC-FLD). The possibility of developing chronic non-carcinogenic health risk among consumers of bottled water was evaluated using hazard quotient (HQ). Results: Results showed that BPA migrated from PC and PET water bottles at concentrations ranging from 9.13 to 257.67 ng/L and 11.53 ng/L to 269.87 ng/L respectively. Concentrations of BPA were higher in PET bottled water compared to PC bottled water across all storage conditions. Higher storage temperature and longer storage duration increased BPA concentrations in PC and PET bottled water. Concentrations of BPA in bottled water which were kept in a car and were exposed to sunlight were higher than control samples which were stored indoor at room temperature. Conclusion: No significant chronic non-carcinogenic health risks were calculated for daily ingestion of BPA-contaminated bottled water; calculated HQ was less than one.

Matched MeSH terms: Polymers
Fulltext Optimization of brush-like cationic copolymers for nonviral gene delivery

Wei H, Pahang JA, Pun SH

Biomacromolecules, 2013 Jan 14;14(1):275-84.
PMID: 23240866 DOI: 10.1021/bm301747r

Polyethylenimine (PEI) is one of the most broadly used polycations for gene delivery due to its high transfection efficiency and commercial availability but materials are cytotoxic and often polydisperse. The goal of current work is to develop an alternative family of polycations based on controlled living radical polymerization (CLRP) and to optimize the polymer structure for efficient gene delivery. In this study, well-defined poly(glycidyl methacrylate)(P(GMA)) homopolymers were synthesized using reversible addition-fragmentation chain transfer (RAFT) polymerization followed by decoration using three different types of oligoamines, i.e., tetraethylenepentamine (TEPA), pentaethylenehexamine (PEHA), and tris(2-aminoethyl)amine (TREN), respectively, to generate various P(GMA-oligoamine) homopolycations. The effect of P(GMA) backbone length and structure of oligoamine on gene transfer efficiency was then determined. The optimal polymer, P(GMA-TEPA)(50), provided comparable transfection efficiency but lower cytotoxicity than PEI. P(GMA-TEPA)(50) was then used as the cationic block in diblock copolymers containing hydrophilic N-(2-hydroxypropyl) methacrylamide (HPMA) and oligo(ethylene glycol) monomethyl ether methacrylate (OEGMA). Polyplexes of block copolymers were stable against aggregation in physiological salt condition and in Opti-MEM due to the shielding effect of P(HPMA) and P(OEGMA). However, the presence of the HPMA/OEGMA block significantly decreased the transfection efficacy of P(GMA-TEPA)(50) homopolycation. To compensate for reduced cell uptake caused by the hydrophilic shell of polyplex, the integrin-binding peptide, RGD, was conjugated to the hydrophilic chain end of P(OEGMA)(15)-b-P(GMA-TEPA)(50) copolymer by Michael-type addition reaction. At low polymer to DNA ratios, the RGD-functionalized polymer showed increased gene delivery efficiency to HeLa cells compared to analogous polymers lacking RGD.

Matched MeSH terms: Polymers/administration & dosage; Polymers/chemistry*
Application of solid-phase extraction for trace elements in environmental and biological samples: a review

Wan Ibrahim WA, Abd Ali LI, Sulaiman A, Sanagi MM, Aboul-Enein HY

Crit Rev Anal Chem, 2014;44(3):233-54.
PMID: 25391563 DOI: 10.1080/10408347.2013.855607

The progress of novel sorbents and their function in preconcentration techniques for determination of trace elements is a topic of great importance. This review discusses numerous analytical approaches including the preparation and practice of unique modification of solid-phase materials. The performance and main features of ion-imprinting polymers, carbon nanotubes, biosorbents, and nanoparticles are described, covering the period 2007-2012. The perspective and future developments in the use of these materials are illustrated.

Matched MeSH terms: Polymers/chemistry
Membrane separations

Walter JK, Jin Z, Jornitz MW, Gorrschalk U

Methods Biochem Anal, 2011;54:281-317.
PMID: 21954783
Matched MeSH terms: Polymers/chemistry*
Electrochemical Characteristics of a Polymer/Garnet Trilayer Composite Electrolyte for Solid-State Lithium-Metal Batteries

Walle KZ, Musuvadhi Babulal L, Wu SH, Chien WC, Jose R, Lue SJ, et al.

ACS Appl Mater Interfaces, 2021 Jan 20;13(2):2507-2520.
PMID: 33406841 DOI: 10.1021/acsami.0c17422

Although solid-state Li-metal batteries (LMBs) featuring polymer-based solid electrolytes might one day replace conventional Li-ion batteries, the poor Li-ion conductivity of solid polymer electrolytes at low temperatures has hindered their practical applications. Herein, we describe the first example of using a co-precipitation method in a Taylor flow reactor to produce the metal hydroxides of both the Ga/F dual-doped Li7La3Zr2O12 (Ga/F-LLZO) ceramic electrolyte precursors and the Li2MoO4-modified Ni0.8Co0.1Mn0.1O2 (LMO@T-LNCM 811) cathode materials for LMBs. The Li/Nafion (LiNf)-coated Ga/F-LLZO (LiNf@Ga/F-LLZO) ceramic filler was finely dispersed in the poly(vinylidene fluoride)/polyacrylonitrile/lithium bis(trifluoromethanesulfonimide)/succinonitrile matrix to give a trilayer composite polymer electrolyte (denoted "Tri-CPE") through a simple solution-casting. The bulk ionic conductivity of the Tri-CPE at room temperature was approximately 4.50 × 10-4 S cm-1 and exhibited a high Li+ ion transference number (0.84). It also exhibits a broader electrochemical window of 1-5.04 V versus Li/Li+. A full cell based on a CR2032 coin cell containing the LMO@T-LNCM811-based composite cathode, when cycled under 1 C/1 C at room temperature for 300 cycles, achieved an average Columbic efficiency of 99.4% and a capacity retention of 89.8%. This novel fabrication strategy for Tri-CPE structures has potential applications in the preparation of highly safe high-voltage cathodes for solid-state LMBs.

Matched MeSH terms: Fluorocarbon Polymers; Polymers

Filters

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links