FTIR Spectrometer Research Articles

Measurements of air-broadening parameters of water vapour transitions in the 5090–7490 cm−1 spectral region

High-resolution spectra of H2O with a high signal/noise ratio (2500 at the absorbance equal 1) were recorded with a Bruker IFS 125 FTIR spectrometer covering H2O transitions from 5090 to 7490 cm−1 at the spectral resolution of 0.01 cm−1. The multispectrum fitting procedure has been applied to recover the spectral line parameters from measurements using quadratic speed-dependent Voigt (qSDV) profiles which made it possible to describe the experimental profile at the noise level. The H2 16O line broadening and shift coefficients for 439 lines of 7 vibrational bands 2ν3, ν2 + ν3, 2ν2 + ν3, ν1 + ν3, ν1 + ν2, ν1 + 2ν2 and 2ν1 were measured. A total of 339 lines were studied for the first time. The uncertainty of the broadening coefficients for the unblended H2O absorption lines was 2–4%. The determined parameters are compared to HITRAN12 and experimental values. The ratio between HITRAN data and our broadening coefficient varied from 0.82 to 1.21. The calculations of broadening and shift coefficients were performed in a framework of the semi-classical method and by using an empirical function whose parameters were taken from the literature. The uncertainty of calculations was 5% for the air broadening half-widths on average.

Carbon nanotubes for improving rheological and chemical properties of styrene–butadiene–styrene modified asphalt binder

ABSTRACT This paper studied the effects of CNTs on high-temperature rheological and chemical properties of SBS modified asphalt. Molecular dynamics simulation, DSR, BBR, and FTIR spectrometer were performed to evaluate the molecular motion state, rheological and chemical properties of CNTs and SBS composite modified asphalt binders at different aging states. The MD results indicated that CNTs could absorb components in SBS-modified asphalt and restrict the movement and diffusion of SBS and asphalt molecules, which enhanced the stability of SBS-modified asphalt. Meanwhile, the addition of CNTs could improve the rheological properties, temperature susceptibility, and rutting resistance of SBS-modified asphalt at high temperatures. The heterogeneity between CNTs and SBS-modified asphalt was demonstrated and it was the key to the high-temperature performance improvement. Besides, the low-temperature performance also could be improved by appropriate CNTs content. In addition, the FTIR results suggested that there was a lack of change in chemical functional groups with CNTs modification in asphalt binder. Moreover, the CNTs had a limited impact on delaying oxidation and played an active role in enhancing high-temperature performance under different aging conditions.

THE EFFECT OF HYDROTHERMAL TEMPERATURE AND TIME OF UREA-DOPING ON THE OPTICAL PROPERTIES OF LEMONGRASS-BASED CARBON DOTS

CDs sourced from spiced lemongrass have been produced by hydrothermal method at hydrothermal temperatures of 120 ℃, 140 ℃, 160 ℃ and 180 ℃. The addition of urea as a nitrogen source was carried out in the synthesis of carbon nanoparticles at a hydrothermal temperature of 180 ℃ for two hours and three hours to see the effect on the optical properties of the CDs. The addition of urea gave a different effect on the two CDs. But the energy band gap (Eg) of the two becomes narrower. For two hours of hydrothermal duration, the addition of urea showed a significant increase in absorbance, but a decrease in fluorescence intensity, whereas for three hours, it resulted in an increase in fluorescence intensity. The results of measuring the size distribution of carbon nanoparticles showed a peak value of 52.32 nm. Functional group analysis using the FTIR spectrometer showed that the carbon nanoparticles consisted of C=C, C-O, O-H, 𝐶-N-𝐶 bonds. Urbach energy (Eu) increases with increasing hydrothermal synthesis temperature at 2 hours and 3 hours. The decrease and increase in the Urbach energy (Eu) is caused by the increasing regularity of the hydrothermal temperature as a result of the synthesis time so that the structure of the CDs becomes more stable and homogeneous.

The feasibility of using micro concentrated multiple reflection ATR FTIR accessory in pesticide analysis

Micro-Multiple Reflection ATR (CMRATR) spectroscopy is a technique, using specialized equipment, which allows the enhanced sensitivity of multiple reflection ATR analysis of small amounts of liquids in a confined area hitherto reserved for single reflection equipment. This technique has demonstrated a high level of sensitivity, especially when used in conjunction with an evaporative technique. In this work, the technique will be used with a miniature CMRATR accessory, which has the added advantage of compatibility with the smallest current FTIR spectrometers, to analyze pesticides. The results presented here indicate that the CMRATR/evaporative technique can serve as both qualitative and quantitative support to the existing standard methodology.

Rapid Sensing: Hand-Held and Portable FTIR Applications for On-Site Food Quality Control from Farm to Fork.

Today, one of the world's biggest problems is the assurance of food integrity from farm to fork. Economically motivated food adulteration and food authenticity problems are increasing daily with considerable health and economic effects. Early detection and prevention of food integrity-related problems could be provided by the application of effective on-site food analysis technologies. FTIR spectroscopy coupled with chemometrics can be used for the rapid quality control of a wide variety of food products with fast, high-throughput, accurate and nondestructive analysis advantages. In particular, hand-held and portable FTIR instruments have the potential to surveil food quality and food safety in various critical segments of the food supply chain. In this review, we explore the abilities of hand-held and portable FTIR spectrometers combined with multivariate statistics to conduct a quality evaluation of various food products in terms of food adulteration and authenticity issues. An examination of the literature showed that comparable results were obtained based on detection limits, correlation coefficient (R2) values, standard error values and discrimination power by using both portable/hand-held FTIR spectrometers and benchtop FTIR spectrometers. In conclusion, this review highlights the potential usefulness of portable and hand-held FTIR spectrometers combined with chemometrics for maintaining the food quality through the presentation of various applications that may shed light for on-site food control at any point of the food supply chain.

Thermal infrared spectroscopy studies on skarn minerals for exploration of the Jiama Cu-Mo deposit, Tibet, China

The zonation patterns of skarn minerals, including garnet, diopside, and wollastonite, are important for exploration of skarn deposits. Thermal infrared (TIR) spectroscopy, which covers the wavelength range of 6–14 μm, is a new eco-friendly technology for skarn mineral identification. In this study, the TIR spectra data were collected, using an Agilent 4300 Handheld FTIR Spectrometer from nine drill holes within Jiama Cu-Mo deposit in Tibet, China. This study focuses on the TIR characteristics of grandite-series garnets (i.e., grossular to andradite), which have twin peaks in the 10–13 μm range and a diagnostic absorption valley (T absorption valley) at around 11.5 μm shifting based on the contents of Al2O3 and Fe2O3. The T absorption valley in the zoned garnet sample showed an undulating pattern, shifting towards longer wavelengths from the core to the rim, indicating the increase in Fe2O3 content and a decrease in Al2O3, MnO, and TiO2 content. The mixed spectral features of three significant skarn minerals including garnet, diopside, and wollastonite were used to classify the skarn zonation into garnet skarns, diopside-garnet skarns, and wollastonite-garnet skarns. The results from nine drill holes of the No. 24 exploration line in the cross section showed that the garnet T absorption valley shifted towards shorter wavelengths from the proximal to the distal skarn, as well as from the lower to the upper skarn. Furthermore, intensive copper mineralization occurred in the skarn when the garnet T absorption valley exceeded 11.50 μm. In comparison, the garnet T absorption valley at 11.35–11.50 μm is related to more intense molybdenum mineralization. This study suggests that TIR spectroscopy has the potential to rapidly identify skarn zonation in the field, and providing a suitable vector tool for skarn ore exploration.

Compact silicon-based attenuated total reflection (ATR) sensor module for liquid analysis

Abstract. Infrared attenuated total reflection (ATR) spectroscopy is a common laboratory technique for the analysis of highly absorbing liquids and solids, and a variety of ATR accessories for laboratory FTIR spectrometers are available. However, ATR spectroscopy is rarely found in industrial processes, where compact, robust, and cost-effective sensors for continuous operation are required. Here, narrowband photometers are more appropriate than FTIR instruments. We show the concept and implementation of a compact Si-based ATR module with a four-channel microelectromechanical systems (MEMS) detector. Measurements of liquid mixtures demonstrate the suitability for applications in the chemical industry. Apart from sapphire (for wavelengths below 5 µm) and diamond (extending to the far-infrared region), most materials for ATR elements do not have either high enough infrared transmission or sufficient mechanical and chemical stability to be exposed to process fluids, abrasive components, or aggressive cleaning agents. However, using diamond coatings on Si improves the stability of the sensor surface. In addition, by proper choice of incidence angle and coating thickness, an enhancement of the ATR absorbance is theoretically expected and demonstrated by first experiments using a compact sensor module with a diamond-coated Si ATR element.

Sintesis Khalkon dan Uji Aktivitas Tabir Surya Secara In Vitro

Synthesis of 2’,4’-dihydroxy-3,4-dimethoxychalcone and in vitro test of its sunscreen activity have been carried out. Chalcone was synthesized from 3,4-dimethoxybenzaldehyde and 2,4-dihydroxyacetophenone through Claisen-Schmidt condensation. The synthesis was performed by using KOH 40% under stirring at room temperature for 48 h. The synthesized compounds was characterized using FTIR, GC-MS and 1H NMR spectrometers. Further, the chalcone were screened for its in vitro sunscreen activity by using UV-Vis spectrophotometer. The result showed that the chalcone has been succesfully synthesized in 36.94% Yield. The activity of invitro test showed the chalcone has SPF values with maximal protection category at the consentration 15 µ/mL produce SPF 9.749

Identification of Key Events and Emissions during Thermal Abuse Testing on NCA 18650 Cells

Thermal abuse of lithium-ion batteries (LIBs) leads to the emission of gases, solids, fires and/or explosions. Therefore, it is essential to define the temperatures at which key events occur (i.e., CID activation, venting, and thermal runaway (TR)) and to identify the related emissions for identifying the hazards to which people and especially rescue teams are exposed. For this purpose, thermal abuse tests were performed on commercial lithium nickel cobalt aluminum oxide (NCA) 18650 cells at 50% state of charge in a reactor connected to an FT-IR spectrometer by varying test conditions (feed gas of N2 or air; heating rates of 5 or 10 °C/min until 300 °C). In particular, the concentrations of the gases and the composition of the condensed-phase emissions were estimated. As regards gases, a high concentration (1695 ppmv) of hydrofluoric acid (HF) was measured, while the emissions of condensed matter consisted of organic compounds such as polyethylene oxide and paraffin oil, and inorganic compounds containing Li (0.173 mg/m3) and Al (0.344 mg/m3). The main safety concerns were caused by the temperatures (564 ± 85 °C) reached by the cell during TR, by the HF concentration which exceeded the toxicity limits of 30 ppm, the IDLH defined by the NIOSH, and the diameter of the particles (1.54 ± 0.69 µm) that rose the PM2.5 concentration. These results are also useful for identifying personal protection equipment for rescue teams.

Novel Benzylamine Derivatives: Synthesis, Anti-Mycobacterium Tuberculosis Evaluation and Predicted ADMET Properties

Background: Tuberculosis (TB), a disease caused by the bacillus bacteria Mycobacterium tuberculosis is one of the major contributors of ill health in the world. TB is ranked in the top 10 causes of death globally and it is the leading killer associated with a single infectious agent. According to the World Health Organization (WHO), global number of deaths associated with TB have been slowly declining with 1.3 million in reported 2016 and 2017, and 1.2 million reported in 2018 and 2019. Objective: The synthesis, characterisation, biological evaluations, and the prediction of ADMET properties of the novel benzylamine derivatives. Methods: Commercially available reagents and solvents were purchased from Sigma Aldrich and Merck (South Africa). All chemicals were used as received, unless otherwise stated. The synthesised crude compounds were purified by flash silica gel column chromatography (5 – 30% ethyl acetate in hexane). The successful formation and purity of the synthesised compounds was confirmed by NMR, HRMS and melting point. Results: The respective organic compounds were synthesised by treating 3-ethoxysalcyladehyde, 5-bromo-3-ethoxysalcyladehyde, 5-chloro-3-ethoxysalcyladehyde with various aromatic amines and the products were obtained in good to excellent yields. The 1H and 13C NMR spectra of all the products showed the appearance of the methylene signals ranging from 3.88 – 4.68 ppm and 42.25 – 52.57 ppm respectively. Additionally, most compounds showed anti-Mycobacterium tuberculosis activity that ranged between 20 and 28 µM. Conclusion: A total of 36 compounds were synthesised and successfully biologically evaluated against Mycobacterium tuberculosis (Mtb) H37RV strain. All compounds showed activity against Mtb at concentrations of > 20 µM < 28 µM with the exception of compound one that was active against Mtb at higher concentration (MIC90 > 125 µM).

Preparation of sorbents for solid-phase extraction of benzoic acid from aqueous solutions

Aim to obtain sorbents based on ethylcellulose for solid-phase extraction of benzoic acid from aqueous solutions.
 Material and methods. To create the sorbents for solid-phase extraction, we used the following reagents: ethyl cellulose, copper sulfate pentahydrate, sodium hydroxide, benzoic acid, purified water, ethyl alcohol 95%. The samples of ethyl cellulose-based sorbents were studied by Fourier transform IR spectrometry on an Agilent Cary 630 FTIR spectrometer. The Agilent Microlab PC Expert software was used for registration and primary processing of IR spectra, and for statistical analysis. The capacity of sorbents for solid-phase extraction was evaluated in a dynamic mode. The microstructure of the samples was studied by field emission scanning electron microscopy (FE-SEM) on a Hitachi SU8000 electron microscope. The specific surface area of the synthesized sorbents was measured by low-temperature nitrogen porometry using the Brunauer Emmett Teller approximation, on the Autosorb 1 device, using the Quantachrome AS1Win software, according to a well-known technique.
 Results. А method was proposed for obtaining a sorbent for solid-phase extraction of benzoic acid from aqueous solutions. The IR-spectrometry did not reveal significant differences between ethylcellulose samples and the obtained sorbent samples. The optimal concentrations of ethylcellulose and benzoic acid in the reaction mixture were determined to create a sorbent with a maximum capacity of 19.2 g/g. The differences in the morphological structure of the surface of ethylcellulose matrix and obtained sorbents were described. The specific surface area of ethylcellulose sorbent with a maximum capacity for benzoic acid was 14.10 cm2/g.

Photodegradation and Photoelectrodegradation of Methyl Orange and Methyl Violet Dyes using Graphite/PbTiO3 Composite under Visible Light Irradiation

The composite of Graphite/PbTiO3 has been synthesized for photocatalyst and photo-electrocatalyst of Methyl Orange (MO) and Methyl Violet (MV) degradation using a visible light source. The aims of the research were to study the influence of pH of the solution, iradiation time and kinetics study of MO and MV photodegradation, voltage of photoelectrodegradation of MO and MV. Composite of Graphite/PbTiO3 was synthesized by the sol-gel process with Titanium Tetraisopropoxide (TTIP) solution and Pb(NO3)2 powder as the precursors. Graphite/PbTiO3 composite was characterized using X-ray difractometer and FTIR spectrometer. The diffractogram of Graphite/PbTiO3 composite showed peaks at 2θ = 26.507o as a characteristic diffraction of Graphite, and at 2θ = 31.838o and 39.294o as those of PbTiO3. FTIR spectrum of Graphite/PbTiO3 composite exhibits vibration peaks of TiO2 at 609.5 – 420.5 cm-1 and those of Pb-O at 1337.66 cm-1 until 1395.56 cm-1. The photodegradation results showed that Graphite/PbTiO3 composite can degrade MO and MV optimally at a pH = 3. The photodegradation levels of MO and MV were 90.33% and 88.26% for 30 min of visible light radiation, respectively. The photodegradation of MO and MV were following the first-order reaction with a reaction rate constant of 0.4445 min-1 and 0.4244 min-1, respectively. Meanwhile, the photoelectrodegradation of MO was 96.50% at 10 volts and at pH 11, while the photoelectrodegradation of MV was 95.14% at 10 volts and at pH 7. When compared previous research, this result also shows excellent degradation MO and MV using Graphite/PbTiO3 under visible light irradiation. So that the use of visible lights provides an advantage over the use of UV light.

Inhibiting Effect of Ionic Liquids on Long-Flame Coal Spontaneous Combustion Through Thermokinetic and Microstructure

ABSTRACT To explore the inhibiting effect of ionic liquids (ILs) on coal spontaneous combustion (CSC), the long-flame coal was treated by [BMIM][BF4], [BMIM][NO3], [BMIM][I], [EMIM][BF4], and [BMIM][AcO], the thermogravimetric analyzer and FTIR spectrometer were adopted, and they were used to analyze functional groups and mass loss properties of each sample. The combustion and thermokinetic characteristics were obtained at four heating rates, and the relation between each functional group and apparent activation energy was received. The results indicated that, the content of -OH, -CO-O-, -COO-, and aromatic hydrocarbon -CH in ILs-treated coals reduced conspicuously, and the content of C-O and aromatic ring C=C enhanced. Meanwhile, the mass maximum temperature and ignition temperature for ILs-treated coals was delayed, their reaction capacity was weakened markedly. In addition, their apparent activation energy enhanced, in which [BMIM][BF4] showed a higher apparent activation energy. The active group for -COO-, aromatic hydrocarbon -CH, and hydroxyls were main parameters affecting the CSC characteristics by Pearson correlation coefficient method. Those findings guidance for the efficient application of ILs on field of CSC.

Application Assessment of Electrical Cables during Smoldering and Flaming Combustion

Electrical cables are a potential source of ignition and fire hazards in various types of buildings and industrial installations, as well as in all modes of transportation, including aircraft. Fires in buildings pose the greatest threat to human life and health. The composition of thermal degradation products depends mainly on the type of combustible materials and the type of combustion process—flaming or smoldering. The purpose of this paper was to determine, based on experimental studies, the effects of flaming and smoldering combustion on the response times of fire smoke detectors. In addition, the concentrations of fire gases formed in the process of duct combustion, including CO, SO2, NO2, NO, HCN, HCl, HBr and HF, were measured using an FTIR spectrometer. The results presented confirm the significant effect of the way the cable samples burned on detector tripping time. The highest concentration of smoke (Y) in the test chamber was obtained during flame combustion. It was further found that the characteristics of the cable insulation material used, such as the type of PVC, had a significant effect on the toxicity of the emitted gases. The largest amounts of toxic gases were emitted during the smoldering combustion of a cable with a plasticized PVC sheath.

Spectral emissivity measurement of free-falling particle groups

A solar energy receiver is a device that absorbs solar radiation and transfers the generated heat energy to a heat transfer medium. As a heat transfer medium in solar energy receivers, solid particles can safely absorb strong solar radiation flux and achieve a higher operating temperature. Hence, they have attracted considerable research interest. The emissivity of particles is an important parameter in numerical simulation and efficiency analysis of solid particle receivers. However, it is rarely reported, especially for dispersed particles flowing in receivers. In this study, a measurement system for the normal spectral emissivity of free-falling particles is designed and developed. The system is based on the energy method and uses an FTIR spectrometer as a radiation measurement device, which can achieve measurement in the wavelength range of 2.5–16 µm below 800 °C. The emissivity of the sheet SiC material is measured to verify the reliability of the system. The results are in good agreement with the data published in NIST. Furthermore, the effects of the particle material, temperature, and particle group thickness on the particle group emissivity are studied. It is found that the emissivity of gray ceramic sand particles is not sensitive to the temperature, whereas that of alumina ceramic particles is positively correlated with the temperature. The emissivity of the two particles increases rapidly with the release width of the particle group, which is related to the increase in the mass flow rate of the particle group. Finally, uncertainty analysis of the measurement system is performed. The results measured in this paper can provide the original emissivity data for heat transfer simulation and efficiency evaluation in the receiver.

Detection of Sub-20 μm Microplastic Particles by Attenuated Total Reflection Fourier Transform Infrared Spectroscopy and Comparison with Raman Spectroscopy.

Microplastics are particulate water contaminants that are raising concerns regarding their environmental and health impacts. Optical spectroscopy is the gold standard for their detection; however, it has severe limitations such as tens of hours of analysis time and spatial resolution of more than 10 μm, when targeting the production of a 2D map of the microparticle population. In this work, through a single spectrum acquisition, we aim at quickly getting information about the whole population of identical particles, their chemical nature, and their size in a range below 20 μm. To this end, we built a compact setup enabling both attenuated total reflection Fourier transform infrared (ATR-FTIR) and Raman spectroscopy measurement on the same sample for comparison purposes. We used monodisperse polystyrene and poly(methyl methacrylate) microplastic spheres of sizes ranging between 6 and 20 μm, also measured collectively using a bench-top FTIR spectrometer in ATR mode. The ATR-FTIR technique appears to be more sensitive for the smallest particles of 6 μm, while the opposite trend is observed using Raman spectroscopy. We use theoretical modeling to simulate and explain the ripples observed in the measured spectra at the shortest wavelength (higher wavenumber) region, which appears as an indicator of the microparticle dimension. The latter finding opens new perspectives for ATR-FTIR for the identification and classification of populations of nearly identical micro-scale bodies, such as bacteria and other micro-organisms, where the same measured spectrum embeds dual information about the chemical nature and the size.

Rapid Biomarker-Based Diagnosis of Fibromyalgia Syndrome and Related Rheumatologic Disorders by Portable FT-IR Spectroscopic Techniques.

Fibromyalgia syndrome (FM), one of the most common illnesses that cause chronic widespread pain, continues to present significant diagnostic challenges. The objective of this study was to develop a rapid vibrational biomarker-based method for diagnosing fibromyalgia syndrome and related rheumatologic disorders (systemic lupus erythematosus (SLE), osteoarthritis (OA) and rheumatoid arthritis (RA)) through portable FT-IR techniques. Bloodspot samples were collected from patients diagnosed with FM (n = 122) and related rheumatologic disorders (n = 70), including SLE (n = 17), RA (n = 43), and OA (n = 10), and stored in conventional protein saver bloodspot cards. The blood samples were prepared by four different methods (blood aliquots, protein-precipitated extraction, and non-washed and water-washed semi-permeable membrane filtration extractions), and spectral data were collected with a portable FT-IR spectrometer. Pattern recognition analysis, OPLS-DA, was able to identify the signature profile and classify the spectra into corresponding classes (Rcv > 0.93) with excellent sensitivity and specificity. Peptide backbones and aromatic amino acids were predominant for the differentiation and might serve as candidate biomarkers for syndromes such as FM. This research evaluated the feasibility of portable FT-IR combined with chemometrics as an accurate and high-throughput tool for distinct spectral signatures of biomarkers related to the human syndrome (FM), which could allow for real-time and in-clinic diagnostics of FM.

Identification of the Radiative Parameters-Albedo and Optical Thickness—Of the Juncus maritimus Fiber

The present work aims to characterize the radiative thermal properties albedo and optical thickness of Juncus maritimus fibers using a FTIR spectrometer. Measurements of normal/directional transmittance and normal and hemispherical reflectance are performed. The numerical determination of the radiative properties is conducted through the computational treatment of the Radiative Transfer Equation (RTE) using the Discrete Ordinate Method (DOM), together with the inverse method, which is done through Gauss linearization. As it is a non-linear system, iterative calculations are necessary, which demand a significant computational cost, and, to optimize this problem, the Neumann method is used for the numerical determination of the parameters. These radiative properties are useful to quantify the radiative effective conductivity.

Evidence of microplastics in leachate of Randegan landfill, Mojokerto City, Indonesia, and its potential to pollute surface water

About 80–90 tons municipal solid waste (MSW) in Mojokerto City, Indonesia, is disposed of into Randegan landfill daily. The landfill was facilitated with a conventional leachate treatment plant (LTP). The plastic waste component in the MSW, which is 13.22 % weight, possibly contaminates leachate with microplastics (MPs). This research aims to determine the presence of MPs in leachate of the landfill, its characteristics, and the removal efficiency of the LTP. The potential of leachate as MP pollutant source to surface water was also discussed. Raw leachate samples were collected from the LTP inlet channel. Leachate samples were also taken from each LTP's sub-units. Leachate collection was performed two times using a 2.5 L glass bottle during March 2022. The MPs were treated using Wet Peroxide Oxidation method, and filtered using PTFE membrane. MP size and shape were determined using a dissecting microscope with 40–60 x magnifications. The polymer types in the samples were identified using Thermo Scientific™ Nicolet™ iS™ 10 FTIR Spectrometer. The average MP abundance in raw leachate was 9.00 ± 0.85 particles/L. MP shape in the raw leachate was dominated by fiber (64.44 %), followed by fragment (28.89 %), and film (6.67 %). The majority of the MPs were of black color (53.33 %). Abundance of 350 - <1000 μm sized MPs was the highest (64.44 %) in the raw leachate, followed by those of 100–350 μm (31.11 %), and 1000–5000 μm (4.45 %). MP removal efficiency of the LTP was 75.6 %, leaving <100 μm fiber shaped MP residuals of 2.20 ± 0.28 p/L in the effluent. Based on these results, effluent of the LTP is considered potential as MP contamination source to surface water.

Ultralong-Cycling and Free-Standing Carboxylated Graphene/PEDOT:PSS Films as Electrode for Flexible Supercapacitors

The rapid development of current wearable electronics motivates the promotion of energy storage devices. Supercapacitor with flexible, lightweight, highly efficient, and long cycling life is one of the potential and glittering candidates. Here, the composite film of carboxylated graphene (CG) and commercially available poly (3, 4-ethylene dioxythiophene): poly (styrene sulfonate) (PEDOT:PSS) are prepared as electrodes for flexible electrochemical capacitors by ultrasonication and vacuum filtration. The CG/PEDOT:PSS films were roundly characterized by SEM, XPS, FTIR, XRD and Raman spectrometer. The as-prepared free-standing films exhibited high specific capacitance (192.7 F g-1 at 0.5 A g-1), excellent rate capability (up to 80.4% from 0.5 to 20 A g-1), and good electrochemical stability (95.5% of specific capacitance retention after 50000 cycles). Surprisingly, the post treated free-standing films by Dimethyl Formamide (DMF) shows better capacitive properties than those of the pristine electrode, such as higher specific capacitance (204.3 F g-1 at 0.5 A g-1), and ultralong-cycling stability (104.6% retention at a high current density of 20 A g-1 after 50000 cycles). It is expected that the free-standing CG/PEDOT:PSS films can be used as flexible electrodes for various wearable energy storage devices.