Benzenesulfonic Acid Sodium Salt Research Articles

Analysis of the Anti-corrosion Performance of Dodecyl Benzene Sulfonic Acid Sodium Salt on Various Heat-Treated Dual-Phase EN8 Steel in an Acidic Environment

This work focuses on the investigation of the corrosion inhibition of heat-treated EN8 steel in the presence of sodium salt of dodecyl benzene sulfonic acid in 0.5 M H2SO4 using the Gravimetric and Electrochemical methods. Austenitizing is performed at 700, 750, 790, and 900 °C for 2 h followed by quenching in water. When the heat-treated metal is exposed to 0.5 M H2SO4 at the temperature of 30, 40, 50, and 60 °C in the presence of dodecyl benzene sulfonic acid sodium salt inhibitor, the corrosion inhibition increased with different heat treatment conditions depending on the phase change. This work investigates the activation and adsorption isotherm parameters. The adsorption isotherms were used to estimate Gibb's free energy change. The inhibition efficiency increased with inhibitor concentration and decreased with temperatures. Out of all the isotherms examined, the Langmuir adsorption isotherm produced the best-fit results, according to the adsorption study. Corrosion and inhibition on the metal's surface were confirmed by surface characterization.

Molecular structure of methyl orange and its role in the process of [Pd(Azo)] compound and MOF formation

In this work, we follow the process of metalorganic complex formation between Pd(II) ions and 4-[4-(Dimethylamino)phenylazo]benzenesulfonic acid sodium salt (methyl orange) in the area of its tautomeric equilibrium. Using UV–Vis spectrophotometry we followed intermediate stages related to inorganic complex association, ligand exchange, cis – trans complex isomerization, and bonding of metal to nitrogen and carbon in the phenyl ring. Obtained double kinetic curves registered at 470 and 273 nm suggest, that the process of complex formation and the cis – trans isomerization is first order in respect to methyl orange. For the process of metalorganic complex formation the activation parameters like energy, enthalpy, and entropy were determined (EA=45.69kJmol,ΔH≠=43.1±1.8kJmol,ΔS≠=−172.6J/(mol·K), respectively) using Arrhenius and Eyring dependencies. Moreover, based on obtained results coming from spectrophotometric study and DFT calculations, the mechanism and molecular structure of the intermediates and products during the process of metalorganic complex formation, were proposed. It was shown, that process takes place in four stages. The two first are related to N – Pd and Pd – C bond formation, and the next one is associated with H- shaped bridge formation. As the last one is aging leading to more complex structure building and finally to metal-organic frameworks formation.

Electroremoval of copper ions from aqueous solutions using chemically synthesized polypyrrole on polyester fabrics

Herein, polypyrrole films are coated on polyester (PET) fabrics via environmentally friendly chemical oxidative polymerization method producing conducting fabrics of excellent electrical conductivity. The electrical resistance of the developed conducting textile is 11 kΩ compared to 90 MΩ for the untreated textile fabrics. The developed flexible conducting fabrics are used for efficient removal of copper ions through electrochemical reduction at constant applied potential to the fabrics. The effect of different types of dopants namely 2-naphthalene sulfonic acid sodium salt (NSA), anthraquinone-2-sulfonic acid sodium salt (AQSA), benzene sulfonic acid sodium salt (BSA), and sodium dodecyl sulfate (SDS) is studied on the polymerization efficiency of polypyrrole chains on polyester fabrics. The efficiency of electro removal of copper ions from solutions is explained in terms of the structural differences between the different dopants used during the polymerization step. Additionally, the influence of different dopants on the capability of developed flexible-polypyrrole based electrode for electroremoval of copper ions was studied. The developed flexible electrode realizes a removal uptake capacity of 61.5 mg/g of coated fabrics using anthraquinone-2-sulfonic acid sodium salt as dopant with a removal efficiency of 69%. The effect the initial copper ions concentrations on the removal efficiency is also evaluated. The developed conducting fabrics are characterized using spectroscopic, X-ray diffraction (XRD), microscopic and surface electrical resistance measurements. This study introduces new and cost-effective approach for facile synthesis, simple processing and safe handling of flexible conducting textile based-electrode for the electrochemical removal and recovery of Cu (II) ions form aqueous solutions with superior merits compared to previously reported surfaces.

Removal of organic dye compounds in water and wastewater samples based on covalent organic frameworks -titanium dioxide before analysis by UV-VIS spectroscopy

A simple and rapid microwave-assisted combustion method was developed to synthesize homogenous carbon nanostructures (HCNS). This research presents a new and novel nanocomposite structures for removal of methylene red (2-(4- Dimethylaminophenylazo)benzoic acid), methylene orange (4-[4-(Dimethylamino)phenylazo]benzenesulfonic acid sodium salt) and methylene blue (3,7-bis(Dimethylamino)phenazathionium chloride)with semi degradation-adsorption solid phase extraction (SDA-SPE) procedure before determination by UV-VIS spectroscopy. A covalent organic frameworks (COFs) with high purity were synthesized and characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results indicated that the self-assembled carbon nanostructures (COFs) synthesized with the cost-effective method which was used as a novel adsorbent for adsorption of dyes after semi-degradation of methylene red, orange and blue (1-5 mg L-1) as an organic dye by titanium dioxide (TiO2) nanoparticales in presence of UV radiation. Based on results, the COFs/TiO2 has good agreement with the Langmuir adsorption isotherm model with favorite coefficient of determination (R2= 0.9989). The recovery of dye removal based on semi-degradation/adsorption of COFs/TiO2 and adsorption of COFs were obtained 98.7% and 48.3%, respectively (RSD less than 5%). The method was validated by spiking dye to real samples.

Effect of Co60 irradiation on the degradation and mineralization of sulfonated aromatic compounds in aqueous solutions

As sulfonated aromatic compounds are widely used in industry, they have frequently been detected in aquatic environments. This study evaluated the degradation and mineralization of 2,6-naphthalenedisulfonic acid disodium salt (2,6-NS), sodium 2-naphthalenesulfonate (2-NS), benzenesulfonic acid sodium salt (BS), and 4-vinylbenzene sulfonate sodium (4-VBS) by exposing aqueous solutions of these compounds to Co60 irradiation. The radiolytic degradation of these pollutants was found to follow pseudo-first-order kinetics. The dose required to achieve 90% degradation (D90) of these four sulfonated compounds was 0.480 (2,6-NS), 0.390 (2-NS), 0.194 (BS), and 0.280 kGy (4-VBS). The chemical radiolytic yield (Gvalue) decreased as the absorbed dose increased; moreover, the chemical structures of these compounds affected their radiolytic efficacy. No significant reduction in radiolytic degradation was observed in the presence of inorganic anions (SO42−, Cl−). The radiolytic degradation efficiency was higher when hydrogen peroxide (H2O2, a hydroxyl radical (OH) promoter) was added. The results also showed that combining H2O2, persulfate anions (S2O82−, a sulfate radical anion (SO4−) promoter), or N2O gas (a OH radical promoter) with the sulfonated compounds enhanced the radiolytic mineralization yield and process by reducing the required irradiation energy. In terms of the Co60/O2 system, at an absorbed dose of 12 kGy, the total organic carbon (TOC) removal efficiency was almost 70%, resulting in the observed release of SO42− anions. In addition, the concentration of dissolved oxygen decreased and the pH was lowered. Based on these results, irradiation with Co60 was found to be a useful tool to remedy wastewater containing sulfonated aromatic compounds.

The properties of experimental resin-modified glass-ionomer luting cements (RMGICs) containing novel monomers

ObjectivesTo investigate working and setting times, compressive fracture strength (CFS), compressive modulus (CM), three-point flexure strength (TFS) and tensile flexure modulus (TFM) of commercial, control and experimental RMGICs. MethodsRelyX Luting (RX, 3M-ESPE) and Fuji Plus (FP, GC), two control home liquids and eight new liquid compositions (F1-F4 and R1-R4) comprising different percentages of the monomer HPM (hydroxypropyl-methacrylate) and/or THFM (tetrahydrofurfuryl-methacrylate) with the original monomer HEMA (2-hydroxyethyl-methacrylate) were used in this study. The polymerization was initiated chemically (using benzene sulfonic acid sodium-salt in FP powder and potassium persulfate/ascorbic acid in RX powder). Home and experimental liquids were mixed with the corresponding commercial powder. An oscillating rheometer was used to measure the working and setting times (n=6). 20 cylinders per material (6.0±0.1mm height, 4.0±0.1mm diameter) were fabricated for CFS and CM testing, 20bars per material (25.0±0.1mm length, 2.0±0.1mm width, 2.0±0.1mm thickness) were made for TFS and TFM testing. ResultsAll RX compositions showed longer setting times (p≤0.0001) and lower CFS values compared to their FP counterparts (p≤0.0001). The TFS testing showed that commercial and home RMGICs behaved as brittle materials with linear load/deflection curve while experimental materials showed plastic ductile deformation before fracture. F3, F4 and F2 showed significantly higher CFS values compared to the corresponding home material (p≤0.0001). SignificanceAll new experimental compositions demonstrated working and setting times that are clinically acceptable. The new experimental FP compositions containing THFM (especially F3 and F4) demonstrated improved mechanical properties compared to their corresponding home material.

A new desorption method for removing organic solvents from activated carbon using surfactant.

A new desorption method was investigated, which does not require toxic organic solvents. Efficient desorption of organic solvents from activated carbon was achieved with an ananionic surfactant solution, focusing on its washing and emulsion action. Isopropyl alcohol (IPA) and methyl ethyl ketone (MEK) were used as test solvents. Lauryl benzene sulfonic acid sodium salt (LAS) and sodium dodecyl sulfate (SDS) were used as the surfactant. Activated carbon (100 mg) was placed in a vial and a predetermined amount of organic solvent was added. After leaving for about 24 h, a predetermined amount of the surfactant solution was added. After leaving for another 72 h, the vial was heated in an incubator at 60°C for a predetermined time. The organic vapor concentration was then determined with a frame ionization detector (FID)-gas chromatograph and the desorption efficiency was calculated. A high desorption efficiency was obtained with a 10% surfactant solution (LAS 8%, SDS 2%), 5 ml desorption solution, 60°C desorption temperature, and desorption time of over 24 h, and the desorption efficiency was 72% for IPA and 9% for MEK. Under identical conditions, the desorption efficiencies for another five organic solvents were investigated, which were 36%, 3%, 32%, 2%, and 3% for acetone, ethyl acetate, dichloromethane, toluene, and m-xylene, respectively. A combination of two anionic surfactants exhibited a relatively high desorption efficiency for IPA. For toluene, the desorption efficiency was low due to poor detergency and emulsification power.

Oxidative strss in liver and brain of male growing rats supplemented benzene sulphonic acid

The synthetic organic azo dye sunset yellow is a widely used in food products, such as drinks, yoghurts, ice cream, and sweets. The solutions of this colored dye are not stable in sunlight or in dark, particularly when common food acids (e.g. citric acid and ascorbic acid) are present. The degraded products from sunset yellow are sulphanilic acid and the sodium salt of 2-naphthalene-sulphonic acid-5-amino-6-hydroxyl. These products further undergo deamination upon prolonged sunlight irradiation to produce benzene sulfonic acid sodium salt (BSA-Na) and ammonia as final products. The purpose of the study was to assess the toxicity BSA-Na on the liver and brain of male growing Sprague-Dawley rats. Oxidative stress and related gene transcription of the antioxidant enzymes have been assessed in male growing rats supplemented the different concentration of BSA-Na (34.8, 69.4 and 153.6 µg/kg. b.w.). The results showed that these concentrations of BSA-Na caused significant increase in the activity of the antioxidant enzymes total superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), glutathione reductase (GR) and xanthine oxidase (XO) and significant increase in lipid peroxidation level in liver and brain of growing male rats as compared with their control. A significant retardation in growth rate was observed in rat supplemented BSA-Na. In addition, these concentrations of BSA-Na significantly caused increasein Cu/Zn super oxide dismutase (Cu/Zn SOD) gene transcription. The data clearly demonstrate that BSA-Na can result in oxidative stress in both liver and brain of the growing rat.

Detection of Methyl Orange in Saffron and Other Edibles Using Direct Injection Micellar Liquid Chromatography

A simple, sensitive, rapid and eco friendly micellar liquid chromatographic method was developed for the detection of banned color methyl orange in counterfeit saffron and prepared foodstuffs. Methyl orange (p-[[p-(dimethylamino) phenyl] azo] benzenesulfonic acid sodium salt) is a hazardous dye used in titration and is known to be used as common adulterant in counterfeit saffron and cooked foodstuffs like Jalebi (Indian sweet), mango shake, Namkeen (salted snacks), tomato ketchup and ice candy etc., due to its pleasant orange color. In the present work, methyl orange was detected in various food samples using direct injection micellar liquid chromatography without any pretreatment step. A C18 column with an optimum micellar mobile phase containing 0.05-M sodium dodecyl sulfate (SDS), 2 % pentanol buffered to pH 7 was used. Detection was carried out at 458 nm. The retention time was 3.7 min without showing any matrix effect. Linearity (r > 0.9999), intraday and interday precision RSD (%) was less than 1.00 in micellar media. Limit of detection and quantification was found to be 0.05 mg/kg and 0.10 mg/kg, respectively. Robustness study was also included as a part of method validation. The developed method proved to be reliable and sensitive for determination of methyl orange in real food samples.

Synthesis, Crystal Structure, and Thermal Stability Properties of a Novel 1D [Co (II) Coordination Polymer Co(L)(4,4′-Bipy)(H2O)

A 1D chain coordination polymer, namely, [Co(L)(4,4′-Bipy)(H2O)]n (1), where Na2L = 2-[(2-Hydroxy-benzylidene)-amino]-benzenesulfonic acid sodium salt and 4,4′-Bipy = 4,4'-bipyridine, has been synthesized and characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis, and single-crystal X-ray diffraction. It crystallizes in monoclinic, space group P2(1)/n. The sulfonate-derived Schiff base serves as a common N, O, O′-tridentate ligand and 4,4′-Bipy in the complex (1) act as μ2-bridging ligand linking adjacent two metal ions into 1D zigzag infinite chain. The 1D chain is further constructed into 3D networks via intermolecular hydrogen bonds between the phenolato oxygen atom and coordinated water.

QUAL2E 모형을 이용한 하천수질의 위해성평가

In this study, we consider ability of self-purification for a rational water quality management. And we assess the risk of Alkyl Benzene Sulfonic acid sodium salt(ABS) of harmful ingredients in Anseong Cheon watershed using QUAL2E model. The observations and simulated results were fitted well for BOD and ABS, but even though the trend of DO concentration change was well represented, the error between observation and simulation values was existed. We assessed the Risk assessment by calculating Risk quotient(RQ) by Predicted Exposure Concentration(PEC) and Predicted No-Effect Concentration(PNEC). Results of the impact of ABS on the self-purification of the river were Anseongcheon[0.0003(Bressan), 0.06(Criteria of Ministry of environment)], Jinwicheon[0.0002(Bressan), 0.04(Criteria of Ministry of environment). And result of the impact of ABS on the Aquatic ecosystem of the river were Anseongcheon[0.0667(Bressan), 0.005(Criteria of Ministry of environment)], Jinwicheon[0.1(Bressan), 0.0075(Criteria of Ministry of environment). All of these results were smaller than the 1.0 which is the reference value suggested by Norification No.30 of the National Institute of Environment Research. So, ABS did not affect a self-purification and aquatic ecosystem of the river. The method suggested in the study is a simple one and can provide more information for harmful ingredients than criteria of Ministry of environment.

Azo-conjugated half-sandwich Rh/Ru complexes for homogeneous water-oxidation catalysis

Herein we report the molecular structures and electronic properties of ionic, hydrophobic, half-sandwich complexes of the formula [η(5)-Cp*Rh(L)(MeOH)] (1) and [η(6)-CyRu(L)(H2O)] (2), where L is azo-dye compound of (p-(2-hydroxy-1-naphthylazo)benzenesulfonic acid sodium salt). Both these complexes have been investigated electrochemically and found to display good electronic properties for use as water-oxidation catalysts potentially.

Novel proton exchange membrane based on crosslinked poly(vinyl alcohol) for direct methanol fuel cells

In this study, we report the synthesis and the characterization of poly (vinyl alcohol) based proton conducting membranes. In particular, we describe a novel physically and chemically PVA/HFA (poly (vinyl alcohol)/hexafluoroglutaric acid) blending membranes with BASANa (Benzenesulfonic acid sodium salt) and GA (Glutaraldehyde) as binary reaction agents. The key PEM parameters such as ion exchange capacity (IEC), water uptake, proton conductivity, and methanol permeability were controlled by adjusting the chemical composition of the membranes. The IEC value of the membrane is found to be an important parameter in affecting water uptake, conductivity as well as the permeability of the resulting membrane. Plots of the water uptake, conductivity, and methanol permeability vs. IEC of the membranes show a distinct change in the slope of their curves at roughly the same IEC value which suggests a transition of structural changes in the network. The proton conductivities and the methanol permeability of all the membranes are in the range of 10−3–10−2 S cm−1 and 10−8–10−7 cm2 s−1, respectively, depending on its binary crosslinking density, and it shows great selectivity compared with those of Nafion®-117. The membranes display good mechanical properties which suggest a good lifetime usage of the membranes applied in DMFCs.

Recyclability of poly (N-isopropylacrylamide) microgel-based assemblies for organic dye removal from water

Poly (N-isopropylacrylamide)-co-acrylic acid (pNIPAm-co-AAc) microgels and their aggregates have been shown to effectively remove organic dye molecules from aqueous solutions. Here, we investigate the reusability of these microgel-based systems by exposing them to the organic azo dye molecule, 4-(2-hydroxy-1-naphthylazo) benzenesulfonic acid sodium salt (Orange II). Following exposure, the microgels are isolated, and added to methanol to extract the trapped Orange II from the microgels, followed by a subsequent isolation. The isolated microgels were then exposed to Orange II once again, and the uptake efficiency of the recycled microgels determined. We found that the microgels and their aggregates could be reused to remove the organic dye with little loss in extraction efficiency with the number of recycling cycles.

Poly(N‐Isopropylacrylamide)‐Based Microgels and Their Assemblies for Organic‐Molecule Removal from Water

We review our recent efforts utilizing poly(N-isopropylacrylamide)-co-acrylic acid (pNIPAm-co-AAc) microgels and their assemblies for the removal of an azo-dye molecule, 4-(2-Hyrodxy-1-napthylazo) benzenesulfonic acid sodium salt (Orange II), from aqueous solutions. First, the ability of dispersed, single microgels to remove Orange II from aqueous solutions at room temperature is discussed. Uptake efficiency (i.e., the amount of Orange II removed from water) increased with AAc composition in the microgels, yielding a maximum uptake efficiency of 29.5% for pNIPAm microgels with 10% AAc. Assemblies of microgels (aggregates) were also investigated for their removal efficiency, which yielded a maximum uptake efficiency of 44.1% at room temperature. Removal efficiencies for the microgels and their aggregates were also monitored at elevated temperatures, and a maximum of 56.6% removal efficiency was achieved for unaggregated microgels, while aggregates were able to remove 73.1% Orange II. To further explore the impact of the microgel system's structure on function, we investigated the role microgel size in the aggregates plays on the uptake efficiency. Initial observations showed that the aggregates composed of microgels with large diameter yielded improved uptake efficiency over the aggregates composed of small diameter microgels. Langmuir sorption isotherms were fit to the data for the dye removal by the unaggregated and aggregated microgels, which showed good fits in all cases.

Poly (N-isopropylacrylamide) microgel based assemblies for organic dye removal from water: microgel diameter effects

Poly (N-isopropylacrylamide)-co-acrylic acid (pNIPAm-co-AAc) microgel based assemblies (aggregates) were synthesized from microgels of various diameters via polymerization of the crosslinker N,N′-methylenebisacrylamide (BIS) in the presence of microgels in solution. We investigated the ability of the respective aggregates to remove the organic, azo dye molecule 4-(2-hydroxy-1-napthylazo) benzenesulfonic acid sodium salt (Orange II) from water at both room and elevated temperatures. The results from the microgel aggregates made from 1.1-μm-diameter [Parasuraman and Serpe. ACS Applied Materials & Interfaces, 2011] microgels were compared to aggregates synthesized from 321-nm and 1.43-μm-diameter microgels. Aggregates made from the same size microgels showed increased uptake efficiency as the concentration of BIS in the aggregates was increased, while for a given BIS concentration, the uptake efficiency increased with increasing microgel size in the aggregate. We attribute this to the “nature” of the aggregates; aggregates have void space between the microgels that can serve as reservoirs for Orange II uptake—the void spaces are hypothesized to increase with larger diameter microgels. By exploiting the thermoresponsive nature of the microgels, and microgel based aggregates, 85.3 % removal efficiencies can be achieved. Finally, all uptake trends for the aggregates, at room temperature, were fit with a Langmuir sorption isotherm model.

Electrochemiluminescence of SDBS‐Ru(bpy)32+‐CPM System and Its Application

AbstractWhen the concentration of dodecyl benzene sulfonic acid sodium salt (SDBS) is 0.7 mmol·L−1, the electrochemical and electrochemiluminescence (ECL) intensity of Ru(bpy)32+‐chlorpheniramine maleate (CPM) system at the Au electrode were studied. The results showed that compared with the absence of SDBS, enhancement of the ECL intensity was 14‐fold at Au electrode. Base on this, an ECL method was established for efficient and simple determination of CPM at Au electrode. Under the optimum experimental condition, the enhanced ECL intensities had good linear relationship with the concentration of CPM in the range of 1.0×10−4–1.0×10−7 mol·L−1, and a linear regression equation was obtained as follows: I (counts)=48.805×106c+394.03 (r=0.9975), the detection limit for CPM was 1.4×10−8 mol·L−1. The RSD for 5 times determinations of 1.0×10−5 mol·L−1 CPM was 3.2%. The results of recovery test were between 96.3%–102.5%, and the RSD of recovery test (n=5) was 2.7%. In addition, eleven kinds of tertiary amines‐Ru(bpy)32+ systems were investigated in the absence and presence of SDBS. The results showed that the enhancement of SDBS on ECL intensity of tertiary amines‐Ru(bpy)32+ systems was universal.

Poly (N-Isopropylacrylamide) Microgel-Based Assemblies for Organic Dye Removal from Water

Poly(N-isopropylacrylamide)-co-acrylic acid (pNIPAm-co-AAc) microgel assemblies (aggregates) were synthesized via polymerization of the cross-linker N,N'-methylenebisacrylamide (BIS) in the presence of microgels in solution. In this case, the microgels were entrapped in the polymerized cross-linker network. The aggregates were investigated for their ability to remove the organic, azo dye molecule 4-(2-hydroxy-1-napthylazo) benzenesulfonic acid sodium salt (Orange II) from water at both room and elevated temperatures. These results were compared with unaggregated microgels that were previously reported (Parasuraman, D.; Serpe, M. J. ACS. Appl. Mater. Interfaces 2011, 3, 2732.). It was found that the removal efficiency increased at elevated temperature, most likely due to the thermoresponsive nature of the pNIPAm-based aggregates, which expel water of solvation and deswell at higher temperature and reswell when they are cooled back to room temperature. Furthermore, increasing the number of cycles the aggregates are heated and cooled enhanced the percent removal of the dye from water. We also evaluated the effect of increasing cross-linker concentration on the removal efficiency, where we found the removal efficiency to increase with increasing cross-linker concentration in the aggregates. The maximum removal efficiency reached by the microgel aggregates at elevated temperatures was calculated to be 73.1%. This enhanced uptake is due to the presence of larger internal volume between the microgels in the aggregates, which the individual microgels lack. Control studies reveal that the structure and hydrophobicity of the aggregates lead to the enhanced uptake efficiencies and is not due to the presence of BIS alone. We determined that aggregates leak 75.6% of the dye that was originally removed from solution. The removal of Orange II by the aggregates at room temperature was fit by a Langmuir sorption isotherm.

Preparation and Optical Property of Long Single Crystalline ZnO Nanofibers

Long single crystal ZnO nanofibers were synthesized on a large-scale by a simple solvothermal method at low temperature in the presence of dodecyl benzene sulfonic acid sodium salt and hydrazine. X-ray diffraction, scanning electron microscopy, transmission electron microscopy and high-resolution transmission electron microscopy were used to characterize the product. The diameter of the single crystal nanofiber is 50–70 nm and the length is 30–50 μm. Due to the oxygen or the zinc vacancy in the nanofibers, the wide emission in the visible light region is increased, while the sharp UV emission still exists at 388.5 nm.

Preparation of ZnO nanorods by microemulsion synthesis and their application as a CO gas sensor

Zinc oxide nanorods with different surface area were synthesized by surfactant assisted microemulsion method. The alkyl chain length of surfactant would affect aspect ratio of ZnO nanorods. ZnO nanorods synthesized by ethyl benzene acid sodium salt (EBS), which is surfactant with short alkyl chain length, show higher aspect ratio than ones by dodecyl benzene sulfonic acid sodium salt (DBS). These nanorods had diameters in the range of 80–300 nm and length of up to several microns. The Brunauer–Emmett–Teller (BET) surface area of the ZnO nanorods was strongly affected by the morphology of the nanorods. The BET surface area of the nanorods synthesized with EBS was higher than the surface area of the nanorods synthesized with DBS (20.2 and 14.1 m 2/g for EBS and DBS, respectively). The response of ZnO nanorods to CO in air was strongly affected by surface area, defects and oxygen vacancies. The results demonstrate that the microemulsion synthesis is an easy and useful method to synthesize ZnO nanorods with large aspect ratio, which may enhance their gas sensing properties.