Modification of Cu(111) Surface with Alkylphosphonic Acids in Aqueous and Ethanol Solution. An Experimental and Theoretical Study

Alkylphosphonic acids are well known for their ability to form self-assembled monolayers on hydroxide surfaces. A crucial step to understanding fundamentally how these surfaces are created is the elucidation of the interaction process that leads to such interface creation. In this study, we employed electrochemical impedance spectroscopy (EIS), Monte Carlo and molecular dynamics to understand this process. The interaction with the Cu(111) surface of three different alkylphosphonic acids (hexyl-, octyl- and decylphosphonic acids) is evaluated in an aqueous acidic and in an ethanol solution by Monte Carlo and molecular dynamics simulations, while EIS measurements are used to put in evidence the impact of the layer made in ethanol on copper protection. Nyquist diagrams of copper samples modified with an alkylphosphonic monolayer showed a higher polarization resistance that mitigates the copper corrosion in an aqueous acid medium. The phase–frequency Bode plots had higher and broader phase maxima for a modified copper surface with phosphonic moieties, which confirmed the ability of this organic layer to prevent copper corrosion.

Redox Flow Capacitive Deionization in a Mixed Electrode Solvent of Water and Ethanol

In the redox flow electrode capacitive deionization (FCDI), the solubility of redox electrolyte and flowability of carbon slurry have great influence on the salt removal rate and energy consumption. In this work, a mixed solvent electrolyte is proposed in FCDI, which consists of iodide/triiodide redox couples and carbon slurry in the mixed solvent of water and ethanol (1:1). At the current density of 5 mA cm-2, the salt removal rate can reach up to 2.72 μg cm-2 s-1 in a mixed solvent, which is much higher than 1.74 μg cm-2 s-1 in aqueous solution and 2.37 μg cm-2 s-1 in the ethanol solution. This may be owing to the fast transport of ions during redox reaction in organic solvent and the excellent flowability of carbon slurry in the aqueous condition, which can provide more reaction sites for iodide/triiodide redox reaction and faster electron transportation. This unique FCDI with organic and aqueous mixed solvent electrolyte will provide a new perspective for the development of redox flow electrochemical desalination.

Function of oxygen transport in the blood of patients in a state of alcohol deprivation in blood in vitro incubation with ethanol solution

Objective. To estimate the in vitro effect of ethanol on the function of oxygen transport in the blood of patients in a state of alcohol deprivation and in healthy donors.Materials and methods. We analyzed blood samples from 13 male patients aged 22–56 in a state of alcohol deprivation and 11 males aged 20-45 in whom this diagnosis was excluded. The blood was incubated with ethanol solution at a final concentration of 50 μmol/L. The parameters of the function of oxygen transport (р50, рО2, рСО2, рН, АВЕ, НСО3-, ТСО2,SВЕ, SBC) of the blood taken from the cubital vein using an ABL-330 “Radiometr” microgas analyzer were determined.Results. The patients in a state of alcohol deprivation reveal increased affinity of hemoglobin for oxygen, and their acid-base status of the blood becomes alkaline. When ethanol is added in vitro to the blood of patients, the affinity of hemoglobin for oxygen decreases.Conclusion. Decreased affinity of hemoglobin for oxygen upon the in vitro addition of ethanol in the examined patients indicates compensatory and adaptive changes in the oxygen transport of the blood in response to chronic ethanol consumption.

Zein-Based Films Containing Monolaurin/Eugenol or Essential Oils with Potential for Bioactive Packaging Application

Zein is renewable plant protein with valuable film-forming properties that can be used as a packaging material. It is known that the addition of natural cross-linkers can enhance a film’s tensile properties. In this study, we aimed to prepare antimicrobial zein-based films enriched with monolaurin, eugenol, oregano, and thyme essential oil. Films were prepared using the solvent casting technique from ethanol solution. Their physicochemical properties were investigated using structural, morphological, and thermal techniques. Polar and dispersive components were analyzed using two models to evaluate the effects on the surface free energy values. The antimicrobial activity was proven using a disk diffusion method and the suppression of bacterial growth was confirmed via a growth kinetics study with the Gompertz function. The films’ morphological characteristics led to systems with uniform distribution of essential oils or eugenol droplets combined with a flat-plated structure of monolaurin. A unique combination of polyphenolic eugenol and amphiphilic monoglyceride provided highly stretchable films with enhanced barrier properties and efficiency against Gram-positive and Gram-negative bacteria, yeasts, and molds. The prepared zein-based films with tunable surface properties represent an alternative to non-renewable resources with a potential application as active packaging materials.

Nux Vomica 200 CH reduced acute hypnotic effect of alcohol in young toads

Potentized Nux Vomica has been reported to produce antialcoholic effect in mice, rats and toads. The effect relates to consumption of alcohol and alcohol-induced loss of righting reflex (RR). RR’s maintain normal erect posture of an animal and are centrally controlled in the midbrain. In the present study young toads, Duttaphrynus melanostictus were first treated with Nux vomica 200 CH and then partially immersed in 209 mM ethanol solution in such a way that their head remained above the level of ethanol solution. Toadlets were removed from the ethanol solution every 10 min, tested for the loss of RR and returned to the ethanol solution. Toadlets were placed in a supine position on a dry flat surface. Failure to right within 60 sec was considered as the loss of RR. The experiment was repeated 10 times. Control toadlets were pretreated with 90% ethanol instead of Nux Vomica 200 CH. The percentages of toadlets showing loss of RR, both in the control as well as in the Nux-treated groups, were shown in graphs against the duration of exposure to ethanol solution. Differences in the percentage distribution between the control and the treatment groups losing RR were tested by χ2 test. All the experiments were conducted at room temperature. The percentage of toadlets losing RR increased with time of exposure to ethanol solution. The increase was significantly higher with the control than with the Nux-treated group. Nux Vomica 200 CH might have influenced the mid-brain of toadlets thereby countering the hypnotic effect of ethanol in the toadlets.

Suberinic Acids as a Potential Feedstock for Polyol Synthesis: Separation and Characterization

Global sustainability challenges prompt the world to modify its strategies and shift from a fossil-fuel-based economy to a bio-resources-based one and to the production of renewable biomass chemicals. Depolymerized suberinic acids (SA) were considered as an alternative resource to develop bio-polyols that can be further used in polyurethane (PU) material production. Birch (Betula pendula) outer bark was used as a raw material to obtain the SA, extracted with ethanol, and depolymerized with potassium hydroxide ethanol solution. By acidifying the filtrate to pH 5.0, 3.0, and 1.0 and drying it at 50 °C and 130 °C, 12 different SA potential feedstocks were obtained and characterized using chemical (total phenolics content, solubility in DMSO, acid, hydroxyl, and saponification number) and instrumental analytical methods (GC-MS, SEC-RID, DSC, and FTIR). Several bio-polyols were synthesized from the SA sample acidified to pH 1 and dried at 130 °C. Acid number and hydroxyl number values, the apparent viscosity and moisture content were measured. It was concluded that SA have a high enough saponification and acid value to investigate the polyol synthesis route via the esterification reaction. Moreover, SA had OH groups in their structure, which can be exploited for PU material development. The majority of SA compounds had relatively low molecular weight with <1300 Da that are suited for bio-polyol synthesis applied for rigid PU foam development. The synthesized bio-polyols had high hydroxyl number values necessary for bio-polyols to be used for rigid PU foam production.

A Facile Colorimetric Method For Ultra-Rapid And Sensitive Detection of Copper Ions In Water

It is of great meaning to develop a facile, reliable and sensitive method to detect copper ions in water. In the study, a facile method has been developed for rapid and sensitive detection of Cu2+. An interesting phenomenon has been observed that 3,3',5,5'-tetramethylbenzidine (TMB) ethanol solution can be extremely fast passed from colorless to yellow once Cu2+ ions are added. It easily occurs to us that Cu2+ can be quantitatively determined via the absorbance at 904 nm of the color changed TMB solution. More importantly, some specific anions (Cl- , Br- ) can significantly enhance the absorption intensity. Under the optimized experimental conditions, this method exhibits a good linear response range for Cu2+ from 0.5 to 100 μM, with the detection limit of 93 nM. Moreover, the possible detection principle has been explored. It is worth mentioning that the color change can be clearly observed by naked eyes for the detection of 1 μM Cu2+, which is far below the threshold limit of Cu2+ in drinking water suggested by World Health Organization. It means that this method possess great promise for on-site Cu2+ detection.

Pemanfaatan Jerami Padi Sebagai Bioplastik Dengan Menggunakan Metode Perlakuan Pelarut Organik

Jerami padi memilki kandungan selulosa yang dapat dimanfaatkan sebagai bahan baku pembuatan bioplastik. Penelitian ini bertujuan untuk mensintesis bioplastik dari bahan baku jerami padi menggunakan perlakuan pelarut organik serta menganalisis pengaruh rasio massa pati dengan selulosa karakteristik produk bioplastik. Proses delignifikasi jerami menggunakan larutan etanol 5% dan 35% pada suhu 80oC selama dua jam. Bioplastik dibuat dengan rasio massa pati dengan selulosa sebesar 1:0,5; 1:1; dan 1:1,5. Karakterisasi menggunakan metode SEM, XRD, TG-DTA, uji tarik, uji transmisi uap, serta uji degradasi. Hasil penelitian menunjukkan bahwa proses delignifikasi menggunakan etanol menyebabkan peningkatan kadar selulosa serta kristalinitas jerami. Morfologi bioplastik menunjukkan permukaan yang tidak rata serta terdapat bagian matriks yang terpisah dengan fiber. Hasil TG-DTA menunjukkan pengurangan massa bioplastik sebesar 81,01% pada suhu 550oC. Hasil kuat tarik terbaik pada bioplastik yang dibuat dengan rasio massa pati dengan selulosa 1:0,5 pada konsentrasi delignifikasi etanol 35%. Nilai kuat tarik yang diperoleh sebesar 8,773 Mpa. Pengujian degradasi bioplastik dilakukan selama 10 hari diperoleh nilai % degradasi terbesar bioplastik adalah sebesar 99,9%. Rice straw contains cellulose which can be used as raw material for making bioplastics. This study aims to synthesize bioplastics from rice straw using organic solvent treatment and analyze the effect of the mass ratio of starch to cellulose on the characteristics of bioplastic products. The straw delignification process used 5% and 35% ethanol solution at 80oC for two hours. Bioplastics are made with a mass ratio of starch to cellulose of 1:0.5; 1:1; and 1:1.5. Characterization using SEM, XRD, TG-DTA methods, tensile test, vapour transmission test, and degradation test. The results showed that the delignification process using ethanol caused an increase in cellulose content and straw crystallinity. The morphology of the bioplastic shows an uneven surface and there are parts of the matrix that are separated from the fiber. The results of TG-DTA showed a reduction the mass of bioplastic by 81.01% at a temperature of 550oC. The best tensile strength results in bioplastics made with a mass ratio of starch to cellulose 1:0.5 at a delignification concentration of 35% ethanol. The tensile strength value obtained was 8,773 Mpa. The bioplastic degradation test was carried out for 10 days and the largest percentage of bioplastic degradation was 99.9%.

Application of Zeolite Membranes to Dehydrate a Bio-Ethanol Solution Produced by High-Temperature Fermentation

The combination of high-temperature fermentation and membrane separation has the potential to realize a simple on-site process to produce concentrated bioethanol. The performance of dehydration membranes in separating bioethanol was investigated in this study. Three types of zeolite membranes, LTA, MFI, and MOR, were synthesized. Their dehydration ability was compared using a bioethanol solution produced by high-temperature fermentation followed by vacuum distillation. The LTA zeolite membranes deformed and became amorphous while treating the distillate. On the contrary, no significant changes were observed in the MFI and MOR zeolite membranes analyzed by X-ray diffraction after treating the distillate. However, the flux declined when the membranes were in contact with the distillate (pH = 3.8). Neutralizing the distillate to pH 6.6 with sodium hydroxide did not prevent the flux decline. Even though flux decreased by about 20–30%, the MOR membrane showed quite high water-selectivity, with a water concentration of over 99.9% in the permeate, suggesting the feasibility of its application to concentrate bioethanol.