Hydrothermal synthesis and characterization of zeolite from Malaysia’s natural kaolin for adsorption of sodium ion (NA+) from seawater

Zeolite-A is widely known as aluminosilicate mineral that has been intensively used as an adsorbent in the adsorption process for desalination. Desalination is a technique to eliminate sodium ion and other minerals in the water. Because of the nature of seawater, which is very salty, the main purpose of the removal of sodium ion from seawater is to produce a source of clean drinking water. The capability of zeolite-A as an adsorbent makes it suitable to remove sodium ion from seawater. The raw kaolin from a different location (Perak and Johor) that acts as the main source of silica and alumina has been successfully studied to synthesized and transform into the Zeolite�A. The proposed synthesis of zeolite-A from kaolin has been reduced the cost of using synthetic reagent and high energy utilization. The various operating parameters to synthesis zeolite-A from both low-grade kaolin (Perak and Johor) were investigated to produce high crystallinity of zeolite. The alkaline solution (2-3 M NaOH) was added as a modification method for their conventional hydrothermal synthesis process. The calcination and crystallization process was recognized as an important processing stage for the synthesis. For the metakaolin process, the temperature 650 0C and time 240 minutes were used. The crystallization time of 12-16 hours with an aging treatment time of 24 hours was selected in the synthesizing of zeolite. The successful of synthesized Zeolite-A was further characterized by XRD, FESEM, FTIR, PSA and BET. The composition percentage of kaolinite from Perak kaolin (84 %) is higher compared to the Johor kaolin (40.6 %). As demonstrated in this work, Perak kaolin was successfully synthesized into Zeolite-A which give higher crystallinity percentage, 72.97 % compared to Johor kaolin, 46.72 % under 24 hours aging, with 2M NaOH and 12 hour crystallization time. The higher percentage of kaolinite from Perak kaolin gives higher crystallinity percentage of synthesizing zeolite-A compared to Johor kaolin. In addition, the BET surface area of Zeolite-A is higher, 5.26 m2 /g compared to natural zeolite, 2.9 m2 /g. The performance of adsorption capacity of sodium ion (Na+ ) toward synthesized Zeolite-A was further analyzed by batch adsorption analysis (Isotherm and Kinetic Model) and column adsorption analysis (Breakthrough curve model). The various parameter was applied to the batch experiment (Zeolite-A dosage, time, initial sodium ion concentration and volume) and column experiment (Zeolite-A dosage, initial sodium ion concentration and flow rate). For batch adsorption analysis, both the Langmuir model and Freundlich model were used to analyze the adsorption of sodium ion toward Zeolite-A. Langmuir isotherm model shows slightly better fitted with the correlation coefficient, R2 = 0.9074 compared to Freundlich isotherm, R 2= 0.9028. The result from the kinetic model shows the intra particle diffusion model gives better fitted with R2 value is 0.9117 compared to pseudo first order (R2= 0.732) and pseudo second order (R2= 0.8276). In addition, the calculated value of adsorption capacity at equilibrium, qe, is 88.4 mg/g by intra particle diffusion model gives the closest to the experimental value of qe, (92 mg/g) compared to pseudo first order (qe= 205.36 mg/g) and pseudo second order (qe= 104.1 mg/g). For column adsorption analysis, breakthrough capacity, qB was increased by increasing the bed height of zeolite-A and initial sodium ion concentration but decrease when increasing the flow rate. The column kinetic model shows the Adam Bohart model slightly better fitted with R2 range is 0.86-0.95 for flow rate, R2 = 0.82- 0.93 for bed height and R2 = 0.90-0.95 for initial sodium ion concentration compared to Thomas model, R2 = 0.84-0.94 for flow rate, R2 = 0.72-0.89 for bed height and R2= 0.78-0.88 for initial sodium ion concentration and Yoon and Nelson model, R2 = 0.84- 0.94 for flow rate, R2 = 0.69-0.89 for bed height and R2 = 0.78-0.87 for initial sodium ion concentration. It can be concluded that the performance of synthesizing zeolite-A from Perak kaolin was capable of adsorbing sodium ion from seawater solution

Varicella-Zoster viruses associated with post-herpetic neuralgia induce sodium current density increases in the ND7-23 Nav-1.8 neuroblastoma cell line

Post-herpetic neuralgia (PHN) is the most significant complication of herpes zoster caused by reactivation of latent Varicella-Zoster virus (VZV). We undertook a heterologous infection in vitro study to determine whether PHN-associated VZV isolates induce changes in sodium ion channel currents known to be associated with neuropathic pain. Twenty VZV isolates were studied blind from 11 PHN and 9 non-PHN subjects. Viruses were propagated in the MeWo cell line from which cell-free virus was harvested and applied to the ND7/23-Nav1.8 rat DRG x mouse neuroblastoma hybrid cell line which showed constitutive expression of the exogenous Nav 1.8, and endogenous expression of Nav 1.6 and Nav 1.7 genes all encoding sodium ion channels the dysregulation of which is associated with a range of neuropathic pain syndromes. After 72 hrs all three classes of VZV gene transcripts were detected in the absence of infectious virus. Single cell sodium ion channel recording was performed after 72 hr by voltage-clamping. PHN-associated VZV significantly increased sodium current amplitude in the cell line when compared with non-PHN VZV, wild-type (Dumas) or vaccine VZV strains ((POka, Merck and GSK). These sodium current increases were unaffected by acyclovir pre-treatment but were abolished by exposure to Tetrodotoxin (TTX) which blocks the TTX-sensitive fast Nav 1.6 and Nav 1.7 channels but not the TTX-resistant slow Nav 1.8 channel. PHN-associated VZV sodium current increases were therefore mediated in part by the Nav 1.6 and Nav 1.7 sodium ion channels. An additional observation was a modest increase in message levels of both Nav1.6 and Nav1.7 mRNA but not Nav 1.8 in PHN virally infected cells

Kinetic properties of sodium-ion transfer at the interface between graphitic materials and organic electrolyte solutions

Graphitic materials cannot be applied for the negative electrode of sodium-ion battery because the reversible capacities of graphite are anomalously small. To promote electrochemical sodium-ion intercalation into graphitic materials, the interfacial sodium-ion transfer reaction at the interface between graphitized carbon nanosphere (GCNS) electrode and organic electrolyte solutions was investigated. The interfacial lithium-ion transfer reaction was also evaluated for the comparison to the sodium-ion transfer. From the cyclic voltammograms, both lithium-ion and sodium-ion can reversibly intercalate into/from GCNS in all of the electrolytes used here. In the Nyquist plots, the semi-circles at the high frequency region derived from the Solid Electrolyte Interphase (SEI) resistance and the semi-circles at the middle frequency region owing to the charge-transfer resistance appeared. The activation energies of both lithium-ion and sodium-ion transfer resistances were measured. The values of activation energies of the interfacial lithium-ion transfer suggested that the interfacial lithium-ion transfer was influenced by the interaction between lithium-ion and solvents, anions or SEI. The activation energies of the interfacial sodium-ion transfer were larger than the expected values of interfacial sodium-ion transfer based on the week Lewis acidity of sodium-ion. In addition, the activation energies of interfacial sodium-ion transfer in dilute FEC-based electrolytes were smaller than those in concentrated electrolytes. The activation energies of the interfacial lithium/sodium-ion transfer of CNS-1100 in FEC-based electrolyte solutions were almost the same as those of CNS-2900, indicating that the mechanism of interfacial charge-transfer reaction seemed to be the same for highly graphitized materials and low-graphitized materials each other

High performance Na0.5[Ni0.23Fe0.13Mn0.63]O2 cathode for sodium-ion battery

The synthesis of a new layered cathode material, Na0.5[Ni0.23Fe0.13Mn0.63]O2, and its characterization in terms of crystalline structure and electrochemical performance in a sodium cell, is reported. X-ray diffraction studies and high resolution SEM images reveal a well-defined P2-type layered structure, while the electrochemical tests evidence excellent characteristics in terms of high capacity, extending up to 200 mAh g-1, and cycle life, up to 70 cycles. This performance, in addition to the low cost and environmental compatibility of its component, poses Na0.5[Ni0.23Fe0.13Mn0.63]O2 among the best promising materials for the next generation of sodium ion batteries

Poly(ionic liquid)-derived N-doped carbons with hierarchical porosity for lithium and sodium ion batteries

The performance of lithium and sodium ion batteries relies notably on the accessibility to carbon electrodes of controllable porous structure and chemical composition. This work reports a facile synthesis of well-defined porous N-doped carbons (NPCs) using a poly(ionic liquid) (PIL) as precursor, and graphene oxide (GO)-stabilized poly(methyl methacrylate) (PMMA) nanoparticles as sacrificial template. The GO-stabilized PMMA nanoparticles were first prepared and then decorated by a thin PIL coating before carbonization. The resulting NPCs reached a satisfactory specific surface area of up to 561 m2/g and a hierarchically meso- and macroporous structure while keeping a nitrogen content of 2.6 wt %. Such NPCs delivered a high reversible charge/discharge capacity of 1013 mA h/g over 200 cycles at 0.4 A/g for lithium ion batteries (LIBs), and showed a good capacity of 204 mA h/g over 100 cycles at 0.1 A/g for sodium ion batteries (SIBs).Comment: 14 pages, 9 figure

Manganese hexacyanomanganate open framework as a high-capacity positive electrode material for sodium-ion batteries

Potential applications of sodium-ion batteries in grid-scale energy storage, portable electronics and electric vehicles have revitalized research interest in these batteries. However, the performance of sodium-ion electrode materials has not been competitive with that of lithium-ion electrode materials. Here we present sodium manganese hexacyanomanganate (Na2MnII[Mn-II(CN)(6)]), an open-framework crystal structure material, as a viable positive electrode for sodium-ion batteries. We demonstrate a high discharge capacity of 209 mAh g(-1) at C/5 (40 mA g(-1)) and excellent capacity retention at high rates in a propylene carbonate electrolyte. We provide chemical and structural evidence for the unprecedented storage of 50% more sodium cations than previously thought possible during electrochemical cycling. These results represent a step forward in the development of sodium-ion batteries.open212

Performance of nanocrystalline Ni3N as a negative electrode for sodium-ion batteries

Nickel nitride is synthesised by high temperature ammonolysis of nickel(II) hexamine and tris(ethylenediamine) salts. Its electrochemical characteristics are examined in half-cells vs. lithium and sodium. Samples with high surface area are found to have significant reversible charge storage capacity in sodium cells and hence to be a promising negative electrode material for sodium-ion batteries

Analysis of Potassium Ion (K+), Sodium Ion (Na+), and Proteins from Coconut Water Variety of Coconut and Hybrid Coconut

Analysis of potassium ion (K+), sodium ion (Na+), and proteins of Dalam coconut varieties water and Hybrid coconut varieties water have been done. The sample is green coconut which was taken simple random from Deli Tua Barat village in the regency of Deli Tua. Analysis of potassium ion (K+) and sodium ion (Na+) was determined by Atomic Absorption Spectrophotometry method (AAS) and analysis of protein was determined by the Kjeldahl method. From the result analysis of Dalam coconut varieties water contain amount potassium ion 321.60 mg/100 mL + 0,77 mg/100 mL, sodium ion 33.17 mg/100 mL + 1.85 mg/100 mL, and protein 0,18 % + 0.05 %. Whereas Hybrid coconut varieties water contain amount potassium ion 278.67 mg/100 mL + 1.53 mg/100 mL, sodium ion 31.33 mg/100 mL + 0.83 mg/100 mL, and protein 0.48 % + 0.3 %