Surfactant Triton X-100 Research Articles

Optimized Spectrophotometric Method for Creatine and Creatinine Quantification using Alpha Naphthol Sulpha Acetamide Dye

A new spectrophotometric method for the reliable determination of creatine and creatinine in plasma, urine and serum has been developed for routine clinical and pharmaceutical use. This technique makes use of the fact that creatine and creatinine can chemically interact with the azo dye Alpha naphthol Sulpha Acetamide (ASA), producing a compound that is an intense orange color and is measurable at 525 nm for creatine and 520 nm for creatinine, respectively. New features include Triton X-100 surfactant and ideal reaction conditions of 30 °C and pH 3 for creatinine and 20 °C and pH 5 for creatine, respectively. The method shows increased molar absorption within the specified concentration ranges and complies with Beer's law. This technique is more friendly to the environment than traditional colorimetric, enzymatic, chromatographic, and immunoassay procedures because it utilizes less hazardous chemicals and biodegradable surfactants. Ethanol is a safer solvent than traditional organic solvents utilized in many processes. It is more environmentally friendly and less harmful. The approach lowers energy consumption and waste by functioning at lower temperatures, consistent with the principles of green chemistry. This method guarantees accurate and dependable identification of creatine and creatinine while promoting environmentally sustainable laboratory practices.

Solvatochromic Analysis of Triton X-100 in Binary Mixtures

Binary solvent mixtures of the non-ionic surfactant Triton X-100 with water, methanol, ethanol, and 1-propanol, respectively, were investigated by solvatochromic studies. The absorption spectral bands of methyl red dye, used as a solvatochromic probe, were recorded in ternary solutions prepared with different mole ratios between Triton X-100 and water/alcohols. The Kamlet–Abboud–Taft model was applied to estimate the contribution of each type of intermolecular interaction to the total shift of the electronic absorption band of the solute. The composition of the solute molecule’s first solvation shell was comparatively estimated by using three models: the statistical cell model of ternary solutions, the Suppan model, and the Bosch–Rosés model. The statistical cell model allows the estimation of the difference between the interaction energies in the solute–solvent pairs of molecules. The Bosch–Rosés model provided important information on the 1:1 complex formed between Triton X-100 and water/alcohol molecules, as well as on the symmetry/asymmetry related to the binary mixtures in the cybotactic region of the solute’s molecule.

Differences in Nanoplastic Formation Behavior Between High-Density Polyethylene and Low-Density Polyethylene.

High-Density Polyethylene (HDPE) and Low-Density Polyethylene (LDPE) films were used to create nanoplastic (NP) models, with the shape of delamination occurring during degradation. In the case of HDPE, selective degradation occurred not only in the amorphous part, but also in the crystalline part at the same time. Some of the lamellae that extend radially to form the spherulite structure were missing during the 30-day degradation. The length of these defects was less than 1 µm. HDPE disintegrated within units of spherulite structure by conformational defects in lamellae, and the size of the fragments obtained had a wide distribution. LDPE was synthesized by radical polymerization, so it contained a cross-linked part. The part was not sufficiently fused, and when it degraded, it delaminated and separated preferentially. The zeta potential reached a minimum value of approximately -20 mV at the degradation time of 21 days, and then increased. This complex dependence on degradation time was due to NP particle aggregation. The addition of 1% Triton(R) X-114 surfactant was effective in stabilizing the NP dispersion. The particle size remained constant at around 20 nm for degradation times of 15-30 days.

Synergy between bacteria and fungi contributes to biodegradation and methane production of lignocellulosic anaerobic co-digestion exposing to surfactants

Surfactant is generally regarded to enhance the hydrolysis rate and favor high efficiency which however has not been revealed in the lignocellulosic anaerobic co-digestion process. In particular, the responses and functions of fungal community exposing to surfactants remain largely unknown. In this study, the roles of dodecyl dimethyl benzyl ammonium chloride (DDBAC, cationic), linear alkylbenzene sulfonate (LAS, anionic) and Triton X-100 (TX, nonionic) surfactants on the lignocellulosic anaerobic co-digestion were investigated. 1 mg/L DDBAC, LAS and TX promoted the degradation of lignocellulose and increased biogas yields by 6.85%, 62.76% and 36.96% comparing with the control group (CK). LAS and TX stimulated the growth of Prevotella, Petrimonas and Romboutsia, produced higher activities of cellulase (averagely 4.22 and 3.73 times of CK), generated more volatile fatty acids (VFAs, averagely 2.94 and 2.44 times of CK) and NH4+-N (averagely 1.91 and 1.63 times of the control group), and finally realized efficient acetoclastic methanogenesis. The abundant fungi genera, Pseudallescheria, Pseudeurotium, Monascus and Aspergillus were significantly correlated to lignin, cellulose, VFAs, ammonia nitrogen (NH4+-N), cellulase and coenzyme F420 activities (p < 0.05). Surfactants exposure damaged the connectivity of Proteobacteria with other microbes in the co-occurrence networks while increased the connectivity of Ascomycota to offset the disturbance of surfactants on the fungal community. The synergistic interaction between bacteria and fungi achieved efficient substrate degradation, contributed to the stability of microbial community and resulted in high biogas production. This research provided references for further management of surfactants exposed lignocellulosic anaerobic co-digestion process and systematically biowaste treatment in large-scale farms.

Mixed Micellization and Density Functional Theory (DFT) Studies on the Molecular Interactions between Gemini and Nonionic Surfactants

In the present study, the mixed micellization behavior of gemini surfactant-1, 5-bis (N-hexadecyl- N, N-dimethylammonium) pentane dibromide (G5) with non-ionic surfactant triton X-100 (TX-100) was investigated in the micellar phase by utilizing the conductometric technique. The deviation of ideal critical micelle concentration (cmc*) from experimental critical micelle concentration (cmc) has been estimated using well-known Clint's theory of mixed micelles. The regular solution approximation was used to determine the interaction parameter (β) and found to be negative. The negative values of β at all mole fractions confirm an attractive interaction between two mixed components. The activity coefficients and excess Gibbs free energy of mixed micelles have been calculated by using different approximations, like Rubingh, Lange and Motomura. Counterion binding (g) computed from the post and premicellar slopes of specific conductance vs. concentration graph. Overall, in most of cases, in presence of TX-100, the counterion binding of gemini surfactant was found to be less in magnitude. The molecular interaction was also investigated by the density function theory (DFT). A polarizable continuum model (PCM) was used (with water as a solvent) to optimize the single surfactants and their mixture. The computational process was carried out by the B3LYP method and the 6-31G basis set.

Experimental optimization for synthesis of cerium-doped titanium dioxide nanoparticles by modified sol-gel process

A systematic experimental optimization procedure was developed for the synthesis of cerium-doped titanium dioxide nanoparticles (CeTNPs) based on modified sol-gel process. The nanocomposite was prepared using titanium tetraisopropoxide (TTIP) as a catalyst precursor, while utilizing the non-ionic surfactant Triton X-114 in cyclohexane as a stabilizing agent. The synthesis process was optimized by identifying the main experimental factors that affect the properties of the nanoparticles, primarily the structural phase and particle size. The synthesized samples were characterized by X-ray diffraction (XRD) for phase and size, field emission scanning electron microscope (FE-SEM) for morphology, particle size analyzer (PSA) for size distribution, and Brunaur, Emmett, and Teller (BET) for surface area and pores characteristics. The photocatalytic activity of the optimized sample was tested for the removal of methyl orange (MO) and lead (II) from aqueous solutions, and the results indicate superior performance as the catalyst uptakes were 14.8 mg/l and 11.4 mg/l for methyl orange and lead (II), respectively.The main highlights of the proposed procedure are as follows:•Identification of the key variables impacting the structural and morphological properties.•Establishing the levels of each factor based on experimental findings.•Generation of all possible combinations of factors based on ANOVA, then characterization of the synthesized material from every possible combination.

Eco-friendly, high-effective, and biocompatible sorbent based on specially designed hydroxyapatite nanoparticles for wastewater treatment from non-ionic surfactants

A new approach to the development of sorbents based on surface-modified hydroxyapatite (HAp) nanoparticles (NPs) for extraction of nonionic surfactants is proposed and tested. The essence of the approach is the building HAp NPs through a non-classical oriented attachment (OA) mechanism from smaller NPs under hydrothermal treatment. Based on characterization data and quantum-chemical calculations, a possible mechanism for final NPs formation is suggested. An additive of ammonium nitrate was used as a source of ammonium ions to specifically regulate the process of OA impacting the size of final NPs, the increase of additive amount resulted in the final NPs size decrease. An original procedure for NPs surface modification by fatty acids in order to create required for sorption of nonionic surfactants combination of hydrophobic and hydrophilic areas was developed. Obtained NPs were used as sorbents for extraction of nonionic surfactant Triton X-100 from aqueous solutions, including solutions based on water taken from city water channel, showing extraction efficiency up to 100 %. The extraction efficiency is determined not only by the fatty acid used for surface modification, but also by the location of modifier on NP surface.

Multielemental determination in lubricating oil samples by microwave-induced plasma optical emission spectrometry after extraction induced by emulsion breaking

Extraction induced by emulsion breaking (EIEB) was studied as a strategy for the determination of Al, Cr, Cu, Fe, Mg, Mn, Mo, Ni, and Pb in used lubricating oil via microwave-induced plasma optical emission spectrometry (MIP OES). No significant spectral and nonspectral interferences were observed in the developed method. These were evaluated as a function of the emission intensity of natural molecular species in the N2 plasma and different atomic and ionic emission lines. The time required for extraction was evaluated, and the best sensitivity for all the elements was obtained at 40 min of contact between the sample and the extraction solution in the presence of the surfactant. Doehlert matrix response surface methodology was employed to study the effects and interactions between the nitric acid (extractor) and surfactant (emulsifier) concentrations during sample preparation. The recommended conditions for 3.0 g of sample were as follows: 5.0 mL of extraction mixture consisting of 2.8 mol/L nitric acid and 3.0 % (v v−1) of the surfactant Triton X-114. The limits of quantification obtained were 2.9 (Al), 43 (Cr), 4.0 (Cu), 17 (Fe), 4.0 (Mg), 3.7 (Mn), 7.0 (Mo), 9.2 (Ni) and 45 (Pb) µg kg−1. The method developed was applied in the analyses of lubricating oil samples. The following concentration ranges (mg kg−1) were found: 2.5–106 (Al), 2.8–24.8 (Cr), 3.5–21.4 (Cu), 16.9–199 (Fe), 33.4–64.0 (Mg), 0.57–9.7 (Mn), 4.7–43 (Mo), 1.6–11.1 (Ni) and 2.0–12.6 (Pb).

Application of Cloud Point Extraction of Amoxicillin Determination using Liquid Ion Exchange method Compared with HPLC in Pharmaceuticals

A direct and compassionate approach has been examined to quantify Amoxicillin (AMX) in pharmaceuticals. This method involves a liquid ion exchange process that relies on forming an ion-pair association complex between AMX and Co (II) as a chloroanion complex by the presence of hydrochloric acid and the non-ionic surfactant Triton X-100. The highest wavelength recorded was 357nm. An analysis was undertaken on the impact of the optimal conditions on the separation process, specifically at a temperature of 95°C. After a heating duration of 15 min., the Co(II) concentration was determined to be 100µg/mL, with an optimal TritonX-100 surfactant volume of 0.5mL. Furthermore, an investigation was conducted to analyze the impact of various organic solvents with differing dielectric constants on the dissolution of the Cloud Point Layer. This study aimed to elucidate the most likely structure of the extracted complex was 1:1 [AMX]+; HCoCl4-. The linear calibration curve spanned the concentration range of 5-1000 μg/mL, exhibiting a limit of detection (LOD) of 4.790 μg/mL and a limit of quantification (LOQ) of 14.515 µg/mL. The analysis of Amoxicillin in pharmaceutical samples was conducted using the CPE-ILE method compared to HPLC, aiming to enhance the precision of the CPE-ILE method for determining Amoxicillin.

Effect of Triton X-100 surfactant concentration on the wettability of polyethylene-based separators used in supercapacitors

Polyethylene-based separators are generally unsuitable for aqueous supercapacitors due to their poor wettability with the electrolyte, which impedes ion transport. However, incorporating Triton X-100 (2-[4-(2,4,4-trimethylpentan-2-yl)phenoxy]ethanol) into the aqueous sulfuric acid (H2SO4) electrolyte improves the wettability of polyethylene and facilitates ionic movement through its pores. In this study, Triton X-100 was added to 1.0 M H2SO4 at various concentrations (0.122%–1.210% V/V) to evaluate its impact on supercapacitor performance. Supercapacitors were assembled using activated carbon-filled carbon cloth electrodes, each of the above electrolytes and polyethylene sheet separators. Scanning electron microscopy revealed that the carbon cloth exhibited a uniform fiber distribution and high surface area for activated carbon integration. The polyethylene separator displayed a porous structure with an average pore size of 165 ± 35 nm. Triton X-100 significantly reduced the water contact angle from 101.5° (without surfactant) to 30.2° (with 1.21% V/V Triton X-100), enhancing polyethylene’s wettability. This change from hydrophobic to hydrophilic characteristics enabled the formation of an electrical double layer at the separator/electrolyte interface, improving ionic transport. However, higher Triton X-100 concentrations increased the electrolyte's viscosity, which impeded ion movement. The highest specific capacitance of 55.3 F/g (at a scan rate of 0.005 V s−1) was achieved with 0.488% V/V Triton X-100. The specific capacitance varied with surfactant concentration in a complex manner, influenced by micelle formation and precipitation. These findings were corroborated by cyclic voltammetry and AC impedance spectroscopy.

B-217 Effective Diagnostic Platform and Method to Differentiate the Infectious From Non-Infectious Viruses With Nucleic Acid Detection Workflow

Abstract Background While qPCR has demonstrated high sensitivity, specificity, and ability to deliver reliable quantitative data in clinical samples, such results do not differentiate between infectious and non-infectious viral particles. In view of the principle of the qPCR method itself, the amplification detects the nucleic acid (DNA/RNA) of the virus, not the virus itself. In many cases, it is still possible to detect DNA/RNA fragments from dead viruses in recovered patients, while they are not infectious anymore. This will lead to prolonged quarantine period or treatment for the patients, which could cause great psychological pressure to the patients and increased healthcare burden. Therefore, an effective detection method that can discriminate viable and inviable pathogens is of great significance. Methods SARS-CoV2 viral RNA, SARS-CoV-2 viruses, or clinical samples with SARS-CoV2 infection were diluted in Delta MTM (Molecular Transport Media) to the respective testing concentrations. The samples were incubated with intercalating dye (PMAxx 100nM) with or without Triton X-100 for 10 min. The mixture was then exposed to the photo-activation device for 5-15 min (@ temperature below 37° C). The samples were then subjected to the standard nucleic acid extraction &amp; purification steps with Qiagen viral RNA extraction kit. The extracted RNA was subjected to amplification with SARS-CoV2 Resolute 2.0 &amp; Fortunate 2.1 assays on BioRAD CFX96. Results The viability PCR (vPCR) efficiency was almost 100% for all SARS-CoV2 RNA input tested suggesting that without viral membrane protection, PMAxx dye effectively bound to the naked RNA after photoactivation process, and the bound RNA was not able to be amplified. The vPCR efficiency was further enhanced with addition of surfactant Triton X-100 suggesting the improved permeability of dye through the viral envelope facilitated the PMAxx binding to the nucleic acid. COVID19 positive clinical samples with viral load ≈ Ct 30 treated with or without PMAxx and photo-activation procedures showed distinctive ΔCt value ranging from 9.27±0.18 to 15.01±0.14. The Ct after dye treatment were all non-numeric (non-detectable) if cut-off Ct sets @ 42.0, indicating the complete inhibition after vPCR pretreatment. Since the clinical samples were undergone heat-inactivation pre-treatment, the result shown here indicating that all samples were non-infectious, which was consistent with the samples tested. Conclusions We developed an effective viability PCR detection method and proprietary vPCR device, which was specifically designed for effective dye photo-activation. In addition, the method takes less than 15 min and could be integrated into the existing standard nucleic acid extraction and amplification workflow. Comparing to the standard PCR test result, this method could provide the information not only on the positivity of the tested pathogen, but also its viability, which could be very essential information for public surveillance and diagnostic decisions for healthcare providers.

Synergistic enhancement of oil recovery: Integrating anionic-nonionic surfactant mixtures, SiO2 nanoparticles, and polymer solutions for optimized crude oil extraction

Enhanced oil recovery (EOR) methods are essential for optimizing oil extraction from modern reservoirs. This research delved into the synergistic impact of combining anionic and nonionic surfactant mixtures with silica (SiO2) nanoparticles (NPs) in sodium chloride (NaCl) solutions, alongside the added enhancement of polymers, to improve crude oil recovery. The study comprehensively evaluated stability, rheological characteristics, interfacial tension (IFT) behavior, wettability alterations, and EOR experiments using mixtures of sodium dodecyl sulfate (SDS) and triton X-100 (TX-100) surfactants. Scenarios both with and without SiO2 NPs in a base solution containing 3000 ppm NaCl and 2000 ppm xanthan gum (XG) polymer were examined. Core flooding tests were carried out on San-Saba sandstone core specimens with low permeability. The stability tests and dynamic light scattering (DLS) analysis were performed to assess the stability of NPs in low saline-surfactant-polymer solution. It was observed that NPs significantly reduced the IFT between the test solutions and crude oil, with nanofluids exhibiting satisfactory stability at a 0.4 wt% SiO2 NPs concentration. Core flooding studies demonstrated a synergistic interaction between NPs and the binary surfactant-polymer mixture, resulting in substantially greater incremental recovery of oil in comparison with the case of using binary surfactant-polymer combination alone. The mechanisms contributing to EOR with nanofluids, such as IFT reduction and wettability alteration, were explored. Incorporating NPs at concentrations of 0.1, 0.2, and 0.4 wt% led to incremental oil recoveries of 4.01 %, 12.35 %, and 12.73 % of the original oil in place (OOIP), respectively, as opposed to the recovery achieved using only SDS + TX-100 + XG. Consequently, these findings advance the understanding of the potential application of SiO2 NPs in combination with the binary surfactant-polymer mixture as effective chemical EOR agents. Additionally, these insights aid in identifying suitable sandstone reservoirs for nanofluid application, contributing to the optimization of oil recovery strategies.

Establishment of an Agrobacterium tumefaciens-Mediated Transformation System for Hirsutella sinensis.

Ophiocordyceps sinensis (Berk.) is a complex is formed by Hepialidae larvae and Hirsutella sinensis. Infestation by H. sinensis, interaction with host larvae, and fruiting body development are three crucial processes affecting the formation of O. sinensis. However, research on the molecular mechanism of O. sinensis formation has been hindered by the lack of effective genetic transformation protocols. Therefore, Agrobacterium tumefaciens-mediated transformation (ATMT) was adopted to genetically transform two H. sinensis strains and optimize the transformation conditions. The results revealed that the most suitable Agrobacterium strain for H. sinensis transformation was AGL1, and that the surfactant Triton X-100 could also induce ATMT, although less effectively than acetosyringone (AS). In addition, the endogenous promoters of H. sinensis genes had a stronger ability to drive the expression of the target gene than did the exogenous promoter. The optimal transformation conditions were as follows: AS and hygromycin B concentrations of 100 μM and 50 μg/mL, respectively; A. tumefaciens OD600 of 0.4; cocultivation at 18 °C for 24 h; and H. sinensis used within three passages. The results lay a foundation for the functional study of key regulatory genes involved in the formation of O. sinensis.

Design of green DES-based aqueous two phase systems for lipolytic enzymes extraction

This study pioneers a novel green and cost-effective separation process using reline deep eutectic solvent (DES) for extracting Thermomyces lanuginosus lipase (TlL) from aqueous solutions. For the first time, it has been shown that various potassium organic salts combined with reline DES can induce phase separation in aqueous solutions of the biodegradable non-ionic surfactant Tergitol 15-S9, presenting a groundbreaking alternative to the banned surfactant Triton X-100. This work uniquely applies three different equations to describe the experimental solubility curves. The selection of reline DES is particularly innovative as it avoids significant deactivation effects with three commercial lipases: Candida antarctica lipases A and B, and TlL, with the latter undergoing a detailed study. This includes an unprecedented analysis of its thermodeactivation kinetics in reline DES aqueous solutions. Additionally, a novel investigation of immiscibility regions at different temperatures, involving comprehensive Tie-Line characterizations (slope and length), preceded the evaluation of lipase extraction. Remarkably, the study demonstrates that optimizing the feed composition to contain higher water concentrations can achieve exceptionally high extraction efficiencies (approximately 90%), suggesting a transformative potential for future applications in real aqueous cultures.

Potentiometry in determining the antioxidant capacity of compounds of different hydrophilicity in the joint presence using mixed solvents and surfactants.

In this work, for the first time, the potentiometric method was used to determine the antioxidant capacity (AOC) of compounds of different hydrophilicity in the joint presence using mixed solvents and surfactants. The AOC of model solutions of antioxidants of different hydrophilicity was determined separately and in the joint presence in the media of phosphate buffer-surfactant and mixed solvents-surfactant, using as an example the ascorbic acid and the α-tocopherol. It was shown that the surfactant Triton X-100 is able to solubilize α-tocopherol under the selected conditions, allows to obtain reproducible and accurate results, and has less effect on the equilibrium rate of the K3[Fe(CN)6]/K4[Fe(CN)6] system. Phosphate buffer-ethanol and phosphate buffer-acetonitrile media in the 3:2 ratio with Triton X-100 (5mmol/dm3) were chosen as the analysis conditions (RSD ≤ 6%). The range of determined concentrations was (0.006-0.5)m mmol/dm3 in phosphate buffer-ethanol and (0.006-0.3)m mmol/dm3 in phosphate buffer-acetonitrile. AOC of raw materials infusions was determined in selected media. The positive correlation with the well-known Folin-Ciocalteu assay was obtained.

Effect of Triton X-100 surfactant and agitation on tetramethylammonium hydroxide wet etching for microneedle fabrication

Solid silicon (Si) microneedles have many applications such as skin pretreatment to form micrometer-sized holes in the skin surface in transdermal drug delivery systems. Wet etching based on tetramethylammonium hydroxide (TMAH) is an efficient method to fabricate solid microneedles. However, it is challenging to increase the density of microneedle arrays due to the faster lateral etching than the vertical etching that requires a large initial mask size. In this work, we used wet etching based on TMAH to fabricate solid Si microneedles. One kind of nonionic surfactant, Triton X-100, was introduced into the TMAH solution to suppress the lateral etching. When Triton X-100 was added into TMAH for a given etching condition, the maximum height (attained right before the mask fell off) of microneedles could reach ∼230 μm for 600 μm square-shaped mask size and 700 μm array period, compared to microneedles of maximum 152 μm height for the same mask size and period without surfactant addition. Correspondingly, when the target heights of microneedles were the same as ∼230 μm, denser (down to 700 μm period, 600 μm mask size) microneedle arrays were achieved with the help of Triton X-100, in comparison to arrays down to 900 μm period (800 μm mask size) without surfactant addition. Furthermore, agitation by a magnetic stirring bar is important for the fabrication of dense solid Si microneedle arrays based on TMAH. The microneedle structures were rhombic pyramid in shape with Triton X-100 and agitation. But microneedle structures obtained with Triton X-100 yet without agitation were octagonal pyramid in shape with a much less steep side surface.

Polymer-assisted dispersion of reduced graphene oxide in electrospun polyvinylidene fluoride nanofibers for enhanced piezoelectric monitoring of human body movement

Electrospun graphene oxide (GO)/polyvinylidene difluoride (PVDF) and reduced graphene oxide (rGO)/PVDF piezoelectric hybrid nanofibers were prepared via electrospinning to enhance the β-phase content of the PVDF crystal structure. The addition of rGO increased the number of nucleation sites in the PVDF matrix, leading to an improved β-phase content in the nanofibers. Although the inclusion of GO also increased the β-phase content, rGO addition resulted in higher output voltages due to its greater conductivity compared to GO. rGO/PVDF produced higher output voltages than GO/PVDF because rGO has few oxygen-containing groups on its carbon atoms. The 1 wt% GO/PVDF nanofibers exhibited an 86.24 % β-phase content and an average output voltage of 3.2 V under a 15 N load. The 0.5 wt% rGO/PVDF nanofibers demonstrated an 84.09 % β-phase content and an average output voltage of 3.66 V under the same load. The nonionic surfactant Triton X-100 improved rGO dispersal, enhancing its effectiveness in inducing β-phase formation, and increasing the number of stress concentration points in the nanofibers. A piezoelectric device composed of TX-100/rGO/PVDF nanofibers exhibited stable performance even after 1,500 load cycles, generating an average output voltage of 7.13 V under a 15 N load. This device serves as both an energy harvester and a footwear sensor, offering potential applications in new sports monitoring technologies and self-powered wearables.

Surfactant hydrophilic modification of expanded graphite to fabricate water-based composite phase change material with high latent heat for cold energy storage

Glycine water-based (GW) phase change material (PCM) is considered a promising candidate for cold energy storage due to its lower cost and high latent heat. However, low thermal conductivity hinders its practical application. Adding high thermal conductive fillers can effectively enhance the thermal conductivity of PCM, but it also leads to a decrease in enthalpy. Thus, the study employed a non-covalent functionalization method to modify the thermal conductivity filler of expanded graphite (EG) using the surfactant Triton X-100 (TX-100) in this study. The hydrophilic groups in TX-100 facilitated the formation of hydrogen bonds between modified expanded graphite (MEG) and GW PCM, thereby inhibiting the enthalpy loss of GW/MEG materials. The prepared GW/MEG composites containing 2 to 8 wt% of MEG exhibited thermal conductivities ranging from 0.88 to 1.28 W/(m·K), representing an increase of 46.47 % ∼ 113.35 %. Simultaneously, the melting temperature ranged from −5.35 to −5.65 °C, with a high melting latent heat of 284.6 to 264.5 J/g. After 100 thermal cycles, only minor fluctuations in melting temperature (−1.62 % ∼ +2.20 %) and latent heat (−2.18 % ∼ −4.66 %) were observed. Furthermore, the application of GW/MEG2 in cold storage of strawberries resulted in a significant reduction in pre-cooling time by 56.60 % compared to that of ice storage. The GW/MEG2 materials allow strawberries to be refrigerated for up to 17.86 h within the temperature range of 1.54 ∼ 3.39 °C. This study provides an effective solution for short-distance transportation of perishable food within cold chain logistics system.

Staphylococcus aureus Stress Response to Bicarbonate Depletion.

Bicarbonate and CO2 are essential substrates for carboxylation reactions in bacterial central metabolism. In Staphylococcus aureus, the bicarbonate transporter, MpsABC (membrane potential-generating system) is the only carbon concentrating system. An mpsABC deletion mutant can hardly grow in ambient air. In this study, we investigated the changes that occur in S. aureus when it suffers from CO2/bicarbonate deficiency. Electron microscopy revealed that ΔmpsABC has a twofold thicker cell wall thickness compared to the parent strain. The mutant was also substantially inert to cell lysis induced by lysostaphin and the non-ionic surfactant Triton X-100. Mass spectrometry analysis of muropeptides revealed the incorporation of alanine into the pentaglycine interpeptide bridge, which explains the mutant's lysostaphin resistance. Flow cytometry analysis of wall teichoic acid (WTA) glycosylation patterns revealed a significantly lower α-glycosylated and higher ß-glycosylated WTA, explaining the mutant's increased resistance towards Triton X-100. Comparative transcriptome analysis showed altered gene expression profiles. Autolysin-encoding genes such as sceD, a lytic transglycosylase encoding gene, were upregulated, like in vancomycin-intermediate S. aureus mutants (VISA). Genes related to cell wall-anchored proteins, secreted proteins, transporters, and toxins were downregulated. Overall, we demonstrate that bicarbonate deficiency is a stress response that causes changes in cell wall composition and global gene expression resulting in increased resilience to cell wall lytic enzymes and detergents.

Inhibitory effect of calcium carbonate precipitation induced by Triton X-100 and microorganisms on coal dust

During underground tunnel construction, dust endangers the safety and health of workers. Microbially induced calcium carbonate precipitation (MICP) represents a novel green dust suppression technology for addressing coal dust pollution, capable of effectively mitigating coal dust pollution. Nevertheless, the concentration of urease will exert a certain influence on the performance of MICP to some extent. Therefore, how to improve the efficiency of urease activity on coal dust suppression is a popular research topic. In this study, based on MICP technology, the properties of microbial dust suppression materials were investigated through contact angle, surface tension, and unconfined compressive strength (UCS) tests in combination with molecular dynamics simulations, scanning electron microscopy, and X-ray diffraction using Bacillus megaterium and the nonionic surfactant Triton X-100. The results demonstrate that when the concentration of the bacterial solution is 20 % and the concentrations of urea and calcium chloride are 0.7 mol·L–1, the addition of 1 % Triton X-100 can increase the yield of calcium carbonate to 21.83 %, enhance the structural density of the gel, and increase the UCS by 15.63 %. The calcite and quartz formed on the coal dust surface improved its wettability with a contact angle of only 22°, showing an excellent dust-suppression effect. These research findings serve as a reference for enhancing the MICP dust suppression efficacy and have significant implications for the development and application of microbial dust-suppression agents. This dust suppression method has potential applications in quarries and underground environments.