Sodium Carboxylate Research Articles

Biphasic Sol-Gel Synthesis of Microstructured/Nanostructured YVO4:Eu3+ Materials and Their H2O2 Sensing Ability.

Microstructured/nanostructured YVO4:Eu3+ powders and films were synthesized through a biphasic sol–gel method, aiming at their application as H2O2 sensing materials based on the turn-off luminescence of Eu3+ ions. The synthesis was typically carried out at temperatures of 80 °C or lower by using organic solutions to dissolve vanadium alkoxide and aqueous solutions to dissolve yttrium and europium salts together with sodium carboxylates. The resultant crystalline YVO4:Eu3+ powders and films were characterized as containing micrometer-sized particles comprising primary nanoparticles with high specific surface areas. A comparative study was performed on the H2O2-responsive turn-off luminescence properties for the above samples and those synthesized by a single-phase sol–gel or a conventional solid-state reaction method. The results indicated that the microstructural feature of the samples from the biphasic sol–gel method was effective for detecting H2O2 through its adsorption on the particle surface and quenching of the Eu3+ luminescence. The film samples showed repeatable and quantitative turn-off luminescence, thereby demonstrating their suitability as solid-state H2O2 sensors.

Solution and emulsion behavior of highly soluble carboxylate surfactants with α-substituted phenoxy group

The aqueous solubility of surfactants is an important physicochemical property for their applications, and is expected to be improved by altering the molecular structures. Herein, a series of carboxylate surfactants with α-substituted phenoxy group, namely, sodium α-phenoxy alkyl carboxylates (Cn-ph-Na, n = 12, 14, 16, 18, 20), were synthesized. Their solution and emulsion behaviors were investigated by surface tension, fluorescence probe method, confocal laser scanning microscopy (CLSM) and X-ray diffraction (XRD). Compared with conventional sodium carboxylate surfactants (CnNa), Cn-ph-Na surfactants show extremely high water solubility of 1250, 1100, 800, 670 and 100 mmol·L−1 for n = 12, 14, 16, 18 and 20, respectively, at 25 °C. The reason for this difference is the presence of the phenoxy group, which leads to the weak cohesive forces between the alkyl tails in the solid state. The high solubility of Cn-ph-Na makes it possible to investigate Pickering emulsions stabilized with alumina (Al2O3) nanoparticles hydrophobized by Cn-ph-Na in situ. Both C12-ph-Na and C14-ph-Na can induce double phase inversion of the emulsions with increasing surfactant concentrations. The present work demonstrates the feasibility of adding hydrophobic groups to promote the water solubility of surfactants, providing a new approach for the molecular design and extending application of surfactants.

Apigenin inhibits fibroblast proliferation and reduces epidural fibrosis by regulating Wnt3a/\u03b2-catenin signaling pathway

BackgroundFailed back surgery syndrome (FBSS) is a common complication after the laminectomy. Epidural fibrosis is the major cause of lower back pain and other complications. Numerous studies have shown that apigenin (API) could treat various fibrotic diseases by regulating various signaling pathways, whereas no study has discussed whether API can inhibit fibroblast proliferation and reduce epidural fibrosis after the laminectomy by regulating Wnt3a/β-catenin signaling pathway.MethodsHuman fibroblasts were cultured and treated with API in different concentrations for 24 h. CCK-8 detection and EdU incorporation assay were performed to detect cell viability and cell proliferation. Western blotting analysis was applied to detect expressions of proliferative proteins, Wnt3a, and its downstream proteins. Moreover, the Wnt3a gene was overexpressed in fibroblasts to define the relationship between Wnt3a/β-catenin signaling pathway and fibroblast proliferation. Wnt3a overexpressed fibroblasts were treated with API to verify if it could reverse the effects of API treatment. Twenty-four Sprague-Dawley rats were randomly divided into four groups. Laminectomy was performed and the rats were gavaged with different doses of API or 5% sodium carboxyl methyl cellulose (CMC-Na) solution for 1 month. The abilities of API to inhibit fibroblast proliferation and to reduce epidural fibrosis were evaluated using histological and immunohistochemical analysis.ResultsCCK-8 detection and EdU incorporation assay demonstrated that API could inhibit the viability and proliferation rate of fibroblasts in a concentration-dependent manner. The Western blotting analysis revealed that API could inhibit the expressions of PCNA, cyclinD1, Wnt3a, and its downstream proteins. The overexpression of Wnt3a in fibroblasts could upregulate the expressions of proliferative proteins such as PCNA and cyclinD1. The inhibitory effect of API on PCNA, Wnt3a, and its downstream proteins was partially reversed by overexpression of Wnt3a. Moreover, the results of the histological and immunohistochemical analysis revealed that API could reduce the epidural fibrosis in rats by inhibiting fibroblast proliferation in a dose-dependent manner.ConclusionsAPI can inhibit fibroblast proliferation and reduce epidural fibrosis by suppressing Wnt3a/β-catenin signaling pathway, which can be adopted as a new option to prevent epidural fibrosis after the laminectomy.

Improving the hypoglycemic effect of insulin via the nasal administration of deep eutectic solvents.

This study aimed to develop biocompatible deep eutectic solvents (DESs) as carriers for improving the nasal delivery of insulin. The DES was prepared from malic acid and choline chloride broadly used in foods, drugs, or cosmetics as biocompatible additives. The DES of choline chloride and malic acid (CM-DES) demonstrated lower melting point (-59.1 °C) and higher viscosity (120,000 cP) compared with hydrogels based on sodium carboxyl methyl cellulose (CMC-Na). The conformational structure of insulin does not change in CM-DES as characterized by circular dichroism. The in vitro results showed that CM-DES dissociated gradually but did not disintegrate immediately upon contact with water. CM-DES was able to improve the hypoglycemic effect of insulin significantly at different doses compared with hydrogels or solutions of insulin, which could be ascribed to facilitated penetration of insulin across the nasal epithelia by CM-DES. The hypoglycemic effect of CM-DES loading insulin at a dose of 25 IU/kg was similar to that of subcutaneous insulin at 1 IU/kg. In addition, no evident toxicity to nasal epithelia was observed after nasal administration to rats for seven consecutive days. In conclusion, CM-DES showed promising potential in enhancing the hypoglycemic effect of insulin via the nasal route.

Transforming Single‐Crystal CuO/Cu2O Nanorods into Nano‐Polycrystalline Cu/Cu2O through Lithiation

AbstractOne‐dimensional single‐crystal CuO/Cu2O nanorods were fabricated by controlled oxidation of a copper substrate and examined as the active material in porous anodes for lithium‐ion batteries. Electrochemical testing against Li‐metal revealed that using sodium carboxyl methyl cellulose (CMC) as the binder enabled an excellent capacity retention for 50 cycles, while the use of polyvinylidene fluoride (PVDF) resulted in a continuous capacity fade. Transmission electron microscopy illustrated the phase composition and morphological changes throughout cycling, revealing that for both types of binders, lithiation of CuO and Cu2O disrupted the single‐crystal nanorod structure, producing multiple Cu/Cu2O nanograins within the rods. With continuous cycling the average grain size of these nanocrystals decreased. A significant difference between the CMC and PVDF binder electrodes was the irreversible formation of LiCuO during delithiation for the PVDF case, which can explain the continuous capacity fade. Scanning electron microscopy also revealed microcracks throughout the electrode surface when the PVDF binder was employed.

Surprising Effect of Carbon Chain Length on Inducing Ability of Additives: Elusive Form-II of γ-Aminobutyric Acid (GABA) Induced by Sodium Carboxylate Additives

Herein, we developed the strategy of additive-induced polymorph, realizing the selective crystallization of elusive Form-II of γ-aminobutyric acid, a potent bioactive compound. A series of sodium carboxylate additives with different carbon chain lengths (C2–C8) were identified to induce the crystallization of Form-II. It was found that additive molecules will inhibit the growth of the centrosymmetric Form-I at two opposite ends, thereby precluding it, but they will inhibit the growth of the polar Form-II at only one end so that it survives. Notably, these sodium carboxylate additives exhibited distinct inducing ability for Form-II; that is, the effective critical addition amount required to induce Form-II increases with the increase of carbon chain length. However, the sodium formate is an exception and it cannot induce the Form-II. The difference of the inducing ability of additives was rationalized based on the competition of attachment and detachment behavior of additives on the growth end of Form-I. W...

Fabrication of Water Absorbing Nanofiber Meshes toward an Efficient Removal of Excess Water from Kidney Failure Patients

Excellent water-absorbing nanofiber meshes were developed as a potential material for removing excess fluids from the blood of chronic renal failure patients toward a wearable blood purification system without requiring specialized equipment. The nanofiber meshes were successfully fabricated from poly(acrylic acid) (PAA) under various applied voltages by appropriately setting the electrospinning conditions. The electrospun PAA nanofibers were thermally crosslinked via heat treatment and then neutralized from their carboxylic acid form (PAA) to a sodium carboxylate form poly(sodium acrylate) (PSA). The PSA nanofiber meshes exhibited a specific surface area 393 times that of the PSA film. The PSA fiber meshes showed a much faster and higher swelling than its corresponding film, owing to the higher capillary forces from the fibers in addition to the water absorption of the PSA gel itself. The proposed PSA fibers have the potential to be utilized in a new approach to remove excess water from the bloodstream without requiring specialized equipment.

Evaluation of Polymeric Binders in Aqueous Electrolyte Environment

Energy storage systems utilizing aqueous electrolytes are ever increasing in importance, as they are inherently cheap and safe when compared to their traditional lithium ion battery counter parts. To date, however, no thorough study on binder characteristics in the aqueous environment has been published. This work characterizes an acrylic based polymer, LA133, LA133+Carboxymethyl cellulose (CMC), Styrene-butadiene rubber (SBR), SBR+CMC, and Polytetrafluoroethylene (PTFE) in an LiMn2O4 cathode. Data presented includes cyclic voltammetry (CV), resistivity, and porosity. Future work will focus on characterizing binders for anode materials then galvanostatic cycling of full cells. Figure 1 shows half-cell (CV) data for LiMn2O4 cathodes cycled between 0-0.7 V at reference cycle rates of 3.33 mV/min and daily cycles rates of 30 mV/min. LA133 clearly degrades, while the other binders performed similarly. This is noteworthy, as it directly contradicts LA133’s behavior in organic electrolytes, as Wang, Rui et al. specifically selected it for its stability in the window of 0.1-3.0V [1]. Additionally, SBR appears to have poorer performance at faster scan rates, but the overall slow scan retention was on par with that of Acrylic and PTFE, indicating poor rate capability rather than electrode degradation. Overall slow scan retention is shown more clearly in Figure 2. This again contradicts findings from traditional Li-ion batteries, as Yingjin Wei et al. selected the SBR/CMC binder combination for its superior rate capability [2]. Figure 3 shows resistivity and porosity data for the LiMn2O4 cathodes. Measurements were taken at 10 MPa and 19 MPa of applied pressure, and the average values are presented here. The most noteworthy point is that the addition of CMC clearly reduces the resistivity in both LA133 and SBR. This motivates investigation into pairing CMC with the other binders, which is not traditionally done in Li-ion batteries. References Wang R, Feng L, Yang W, et al. Effect of Different Binders on the Electrochemical Performance of Metal Oxide Anode for Lithium-Ion Batteries. Nanoscale Res Lett. 2017;12(1):575. Published 2017 Oct 30. doi:10.1186/s11671-017-2348-6Yan X, Zhang Y, Zhu K, Gao Y, Zhang D, Chen G, Wang C, Wei Y (2014) Enhanced electrochemical properties of TiO2(B) nanoribbons using the styrene butadiene rubber and sodium carboxyl methyl cellulose water binder. J. Power Sources Figure 1

Study of the degradation mechanisms of oxidized Cellulose-Derivative hemostatic agent by using model compound

Degradable hemostatic agents are the essential materials for controlling the hemorrhage. Hemostatic oxidized cellulose carboxylate sodium fiber (OCCSF) has been synthesized via a simple neutralization reaction between water-insoluble oxidized cellulose fiber (OCF) and NaOH. Importantly, the degradation mechanisms of OCCSF have been investigated in vitro assay. Chemical structure of the material is tested by using FT-IR and NMR, and no obvious change was detected before and after degradation. Degree of polymerization (DP) of OCCSF declines with prolonging the degradation period, accompanying with the decrease in carboxyl content (CC), so that it could be concluded that OCCSF may undergo decarboxylation degradation process. Besides, combined the change of fiber color with UV, another elimination degradation mechanism of OCCSF could be deduced, and this has been demonstrated using 1,2-cyclohexanedione as the model compound.

Effect of Polymers on the Pharmaco-mechanical Properties of Direct Compressed Tablets with Ketoprofen

In this study, the effect of polymers on the mechanical properties of ketoprofen extended drug release systems were studied. Many polymers are added in formulation of compressed tablets in order to improve the physicochemical characteristics of the drug release system. The samples were made in the form of cylindrical tablet about 9 mm in diameter, containing different mixtures of drug substances and excipients acording to seven formulations. Cylindrical tablets containing mixtures of ketoprofen and various types of polymers are made by direct compression method. Among the binders used were a series of different polymers like Kollidon va 64, hydroxypropyl methyl cellulose and sodium carboxyl methyl cellulose. Mechanical parameters such as hardness, mechanical strenght, friability and roughness were studied in order to determine how they are influenced by polymeric binders.

Superabsorbent Poly(isoprenecarboxylate) Hydrogels from Glucose

Isoprenecarboxylic acid (ICA-H), available from glucose via one of its major metabolites mevalonate, has been converted to cross-linked networks by radical polymerization. Monomer feeds comprising various ratios of ICA-H and its sodium salt (ICA-Na) were used to give hydrogels that show attractive performance in comparison with (nonbioderived) poly(acrylate) hydrogels. In particular, these new materials show increasing levels of water uptake (i.e., swelling ratio) across the entire range of ionization (10–90 %Na). This behavior is attributed to the larger distance between carboxylate moieties in the hydrogels, a feature that reduces the average amount of charge repulsion between proximal sodium carboxylate ion pairs (counterion condensation).

Cationic gold nanoparticles elicit mitochondrial dysfunction: a multi-omics study

Systems biology is increasingly being applied in nanosafety research for observing and predicting the biological perturbations inflicted by exposure to nanoparticles (NPs). In the present study, we used a combined transcriptomics and proteomics approach to assess the responses of human monocytic cells to Au-NPs of two different sizes with three different surface functional groups, i.e., alkyl ammonium bromide, alkyl sodium carboxylate, or poly(ethylene glycol) (PEG)-terminated Au-NPs. Cytotoxicity screening using THP-1 cells revealed a pronounced cytotoxicity for the ammonium-terminated Au-NPs, while no cell death was seen after exposure to the carboxylated or PEG-modified Au-NPs. Moreover, Au-NR3+ NPs, but not the Au-COOH NPs, were found to trigger dose-dependent lethality in vivo in the model organism, Caenorhabditis elegans. RNA sequencing combined with mass spectrometry-based proteomics predicted that the ammonium-modified Au-NPs elicited mitochondrial dysfunction. The latter results were validated by using an array of assays to monitor mitochondrial function. Au-NR3+ NPs were localized in mitochondria of THP-1 cells. Moreover, the cationic Au-NPs triggered autophagy in macrophage-like RFP-GFP-LC3 reporter cells, and cell death was aggravated upon inhibition of autophagy. Taken together, these studies have disclosed mitochondria-dependent effects of cationic Au-NPs resulting in the rapid demise of the cells.

Preparation of oxidized celluloses in a NaBr/NaClO system using 2-azaadamantane N-oxyl (AZADO) derivatives in water at pH 10

Catalytic oxidation using N-oxyl radicals in water at pH 10 was applied to wood cellulose to determine the influence of different N-oxyl radical chemical structures on the reaction kinetics and structures of oxidized celluloses. 2,2,6,6-Tetramethylpiperidine-1-oxyl (TEMPO), 2-azaadamantane N-oxyl (AZADO), 1-methyl-AZADO (1-Me-AZADO), 9-azanoradamantane N-oxyl (Nor-AZADO), and 1,5-dimethyl-9-azanoradamantane N-oxyl (DMN-AZADO) were used as oxidation catalysts in a NaBr/NaClO system in water at room temperature and pH 10. The reaction time required for complete oxidation of wood cellulose by 5 mmol/g of NaClO using AZADO, 1-Me-AZADO, or Nor-AZADO was less than 20 min, while DMN-AZADO and TEMPO required 70 min and 120 min, respectively. The sodium carboxylate contents of the oxidized celluloses prepared using TEMPO and DMN-AZADO were 1.41 and 1.45 mmol/g, respectively, which were higher than those of oxidized celluloses prepared using other AZADO derivatives. The original cellulose I crystal structure, crystallinity, and crystal size of wood cellulose were mostly maintained in all oxidized celluloses, with oxidation selectively occurring at C6–OH groups on the crystalline cellulose microfibril surfaces. Oxidized celluloses prepared using DMN-AZADO and post-reduced with NaBH4 showed high carboxylate contents of ~ 1.41 mmol/g and the heist viscosity-average degrees of polymerization of ~ 800.

Preparation and Properties of Highly Electroconductive and Heat-Resistant CMC/Buckypaper/Epoxy Nanocomposites.

Self-assembled buckypapers have been successfully prepared using sodium carboxyl methyl cellulose (CMC) as a binder. The lowest resistivity that was reached was 0.43 ± 0.03 Ω·m, when the buckypapers were prepared by the same mass of CMC and carboxy-modified carbon nanotubes (CNTs). A heat-resistant electroconductive nanocomposite with epoxy resin as the matrix and CMC/buckypapers as the reinforcement was fabricated by a resin impregnation molding technique. The effects of CMC/buckypaper layers on the conductivity, thermal stability, and mechanical and dynamic mechanical performance of the epoxy resin polymer nanocomposites were investigated. It was found that CMC/buckypapers hold great promise for improving the properties of nanocomposites, and the buckypapers’ performance can be enhanced by using modified CNTs to prepare them. The obtained nanocomposites showed an approximate 71.23% bending strength improvement (125.04 ± 5.62 MPa) and a 30.71% bending modulus improvement (5.83 ± 0.68 GPa), with an increased number of CMC/buckypaper layers. An enhanced degradation temperature and residual mass were also achieved for the nanocomposites when compared with a pure polymer. The nanocomposites with four CMC/buckypaper layers possessed the highest storage modulus (1934 MPa), which was approximately 60% higher than that of a neat polymer (1185 MPa). Therefore, CMC/buckypapers could be effectively used to manufacture heat-resistant electroconductive polymer nanocomposites with improved properties.

Surface-hydrophobized TEMPO-nanocellulose/rubber composite films prepared in heterogeneous and homogeneous systems

A surface-carboxylated nanocellulose was prepared from wood cellulose by catalytic oxidation with 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO). The fibrous TEMPO-oxidized cellulose with sodium carboxylate groups (TOC-Na) was surface-hydrophobized by counterion exchange with tetra-n-butylammonium [TOC-N(n-Bu)4]. This fibrous TOC-N(n-Bu)4 was mechanically disintegrated in water and N,N-dimethylformamide (DMF) to prepare dispersions of TEMPO-oxidized cellulose nanofibrils (TOCNs) with tetra-n-butylammonium counterions, i.e., TOCN-N(n-Bu)4/water and TOCN-N(n-Bu)4/DMF. TOCN-N(n-Bu)4/rubber composite films were prepared by mixing TOCN-N(n-Bu)4 and hydrogenated acrylonitrile–butadiene rubber (H-NBR), used as a polymer matrix, in heterogeneous and homogeneous systems with water and DMF, respectively, followed by casting and drying. The TOCN-N(n-Bu)4/H-NBR composite films prepared in the heterogeneous and homogeneous systems both had a high Young’s modulus of ~ 45 MPa and low coefficients of thermal expansion of ~ 20 ppm/K at a TOCN/H-NBR ratio of 5/100 (w/w). In contrast, the tensile strengths and strain-to-failure values of the composite films prepared using the two systems clearly differed. These different properties are probably caused by differences between the TOCN distributions in the H-NBR matrix and between the H-NBR matrix structures in the two systems. The composite films prepared in the homogeneous system with DMF as the medium are likely to have a more homogeneous distribution of TOCN elements in a homogeneous H-NBR polymer matrix, resulting in a higher tensile strength and work-of-fracture at TOCN/H-NBR = 5/100 (w/w) compared with those of the films prepared in the heterogeneous system with water.

Inhibition of Naphthenates Emulsion Soaps Chemical EOR using Synthesis Compound Derived from Fatty Hydrazide.

Naphthenates soaps emulsion generated from alkaline (A), surfactant (S) and polymer (P) flooding were studied with crude oil contained amphiphilic carboxylic acids, RCOOH from Malaysian oilfield. These naphthenic acids were characterised using high-resolution fourier transform ion-cyclotron resonance mass spectroscopy (FTCIR-MS). Alkaline Na2CO3 resulted in increase in pH of produced water to between pH 9 to 11 and generates in-situ oil-rich colloidal dispersion ultralow interfacial tension (IFT) character of sodium carboxylate soaps emulsion. Predictive measurement and inhibition were evaluated using new naphthenate inhibitor (NI)- demulsifier synthesized from fatty hydrazide. The structures of the synthesized compounds have been established by FTIR, 1H NMR, 13C NMR, and mass spectrometry (LCMS/MS). Inhibition and demulsification properties have been evaluated at operating parameters such as produce water cut level, ASP concentration and temperatures under dynamic testing condition using Multifunctional Mini Flow Loop (MMFLTM).

Palladium-Catalyzed Three-Component Reaction: A Novel Method for the Synthesis of N-Acyl Propiolamides.

Palladium-catalyzed three-component reactions between terminal alkynes, isonitriles, and sodium carboxylates have been developed. This novel and operationally simple methodology provides an alternative for the synthesis of N-acyl propiolamide derivatives under mild conditions using isonitriles as the amine source and sodium carboxylates as the oxygen and acyl source.

Luminescent and Transparent Nanocellulose Films Containing Europium Carboxylate Groups as Flexible Dielectric Materials

Transparent, flexible, and luminescent 2,2,6,6-tetramethylpiperidine-1-oxyl radical-oxidized cellulose nanofibril films with europium carboxylate groups (TOCN-Eu) are proposed as potential flexible dielectric materials. The TOCN-Eu films were prepared from TOCN films with sodium carboxylate groups (TOCN-Na) by immersion in Eu(NO3)3 solution and subsequent washing with water and drying of the wet TOCN-Eu hydrogel films. The nanolayered TOCN-Eu films emit red light under ultraviolet-light irradiation and exhibit greatly improved dry and wet mechanical properties, water resistance, thermal stability, oxygen-barrier properties, dielectric breakdown strength, and energy density than conventional TOCN-Na films. These characteristic properties of the TOCN-Eu films are most likely caused by the formation of strong ionic bonds between the carboxylate groups and Eu3+ ions. These high-performance cellulose nanofibril films are promising for application as multifunctional materials in light-emitting, photovoltaic, an...

Synergistic Role of Electrolyte and Binder for Enhanced Electrochemical Storage for Sodium-Ion Battery.

Sodium-ion batteries are promising futuristic large-scale energy-storage devices because of the abundance and low cost of sodium. However, the development and commercialization of the sodium-ion battery solely depends on the use of high-capacity electrode materials. Among the various metal oxides, SnO2 has a high theoretical specific capacity for sodium-ion battery. However, the enormous volume expansion and low electrical conductivity of SnO2 hinder its capability to reach the predicted theoretical value. Although different nanostructured designs of electrode materials like SnO2 nanocomposites have been studied, the effects of other cell components like electrolyte and binder on the specific capacity and cyclic stability are yet to be understood. In the present study, we have investigated the synergistic effect of electrolyte and binder on the performance enhancement of SnO2 supported on the intertwined network structure of reduced graphene oxide partially open multiwalled carbon nanotube hybrid as anode in sodium-ion battery. Our result shows that sodium carboxyl methyl cellulose and ethylene carbonate/diethyl carbonate as the electrolyte solvent offers a high specific capacity of 688 mAh g–1 and a satisfactory cyclic stability for 500 cycles. This is about 56% enhancement in specific capacity compared to the use of poly(vinylidene fluoride) binder and propylene carbonate as the electrolyte solvent. The present study provides a better understanding of the synergistic role of electrolyte and binder for the development of metal-oxide-based electrode materials for the advancement of the commercialization of sodium-ion battery.

Transformation mechanism of sodium during pyrolysis of Zhundong coal

The modes in which Na occurs play an important role in its release and catalytic effects during thermal utilization of Zhundong coal. The modes of Na transform with increasing temperature during pyrolysis, but the transformation mechanism remains unclear. In this study, an acid-washed coal was used as a substrate to eliminate the influence of Na inherently present in the raw coal. Na2SO4, NaCl, NaHCO3, and sodium carboxylate were loaded onto the acid-washed coal by impregnation or ion exchange. Pyrolysis of the sodium-loaded coals was conducted in a fixed-bed reactor. Transformation of Na in chars was studied over the temperature range 300–900 °C. Interconversion of H2O- and CH3COONH4-soluble sodium occurred below 400 °C. CH3COONH4-soluble sodium mainly transformed to H2O-soluble sodium at 400–600 °C. The transformation of Na from the H2O-soluble to insoluble form occurred above 600 °C. The transformation of Na related to its initial form in the coal. Transformation routes and mechanisms of Na are proposed·H2O-soluble sodium can react with COOH to form CH3COONH4-soluble sodium below 400 °C. The decomposition of CH3COONH4-soluble sodium occurred at temperatures lower than 600 °C. H2O-soluble sodium may combine with minerals or be coated by the carbon matrix to form insoluble sodium above 600 °C. Na that volatilized above 600 °C was mainly in the H2O-soluble form.