Colloids and Interfaces最新文献_第4页

In Situ Dilatometry Measurements of Deformation of Microporous Carbon Induced by Temperature and Carbon Dioxide Adsorption under High Pressures 高温和高压下二氧化碳吸附引起的微孔碳变形的原位膨胀测量

IF 2.4

Colloids and Interfaces Pub Date : 2023-06-13 DOI: 10.3390/colloids7020046

A. Shkolin, I. Men’shchikov, E. Khozina, A. Fomkin

{"title":"In Situ Dilatometry Measurements of Deformation of Microporous Carbon Induced by Temperature and Carbon Dioxide Adsorption under High Pressures","authors":"A. Shkolin, I. Men’shchikov, E. Khozina, A. Fomkin","doi":"10.3390/colloids7020046","DOIUrl":"https://doi.org/10.3390/colloids7020046","url":null,"abstract":"Adsorption-based carbon dioxide capture, utilization, and storage technologies aim to mitigate the accumulation of anthropogenic greenhouse gases that cause climate change. It is assumed that porous carbons as adsorbents are able to demonstrate the effectiveness of these technologies over a wide range of temperatures and pressures. The present study aimed to investigate the temperature-induced changes in the dimensions of the microporous carbon adsorbent Sorbonorit 4, as well as the carbon dioxide adsorption, by using in situ dilatometry. The nonmonotonic changes in the dimensions of Sorbonorit 4 under vacuum were found with increasing temperature from 213 to 573 K. At T > 300 K, the thermal linear expansion coefficient of Sorbonorit 4 exceeded that of a graphite crystal, reaching 5 × 10−5 K at 573 K. The CO2 adsorption onto Sorbonorit 4 gave rise to its contraction at low temperatures and pressures or to its expansion at high temperatures over the entire pressure range. An inversion of the temperature dependence of the adsorption-induced deformation (AID) of Sorbonorit-4 was observed. The AID of Sorbonorit-4 and differential isosteric heat of CO2 adsorption plotted as a function of carbon dioxide uptake varied within the same intervals of adsorption values, reflecting the changes in the state of adsorbed molecules caused by contributions from adsorbate–adsorbent and adsorbate–adsorbate interactions. A simple model of nanoporous carbon adsorbents as randomly oriented nanocrystallites interconnected by a disordered carbon phase is proposed to represent the adsorption- and temperature-induced deformation of nanocrystallites with the macroscopic deformation of the adsorbent granules.","PeriodicalId":10433,"journal":{"name":"Colloids and Interfaces","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43159133","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effects of Cooling Rate and Emulsifier Combination on the Colloidal Stability of Crystalline Dispersions Stabilized by Phospholipids and β-Lactoglobulin 冷却速率和乳化剂组合对磷脂和β-乳球蛋白稳定结晶分散体胶体稳定性的影响

IF 2.4

Colloids and Interfaces Pub Date : 2023-06-05 DOI: 10.3390/colloids7020045

J. Reiner, Charlotte Schüler, V. Gaukel, H. Karbstein

{"title":"Effects of Cooling Rate and Emulsifier Combination on the Colloidal Stability of Crystalline Dispersions Stabilized by Phospholipids and β-Lactoglobulin","authors":"J. Reiner, Charlotte Schüler, V. Gaukel, H. Karbstein","doi":"10.3390/colloids7020045","DOIUrl":"https://doi.org/10.3390/colloids7020045","url":null,"abstract":"A lot of applications for (semi-)crystalline triacylglycerol (TAG)-in-water dispersions exist in the life science and pharmaceutical industries. Unfortunately, during storage, these dispersions are often prone to changes in particle size due to unforeseen crystallization and recrystallization events. This results in the alterations of important product properties, such as viscosity and mouthfeel, or the premature release of encapsulated material. In this study, we investigated the effects and interplay of formulation, i.e., emulsifier combination, and processing parameters, i.e., cooling rate, on the colloidal stability of dispersed TAGs and aimed to improve their colloidal stability. We chose phospholipids (PLs) and β-lactoglobulin (β-lg) as the emulsifiers for our model systems, which are commonly applied in many food systems. When dispersions were characterized directly after cooling, we obtained smaller particles and narrower size distributions after fast cooling. Over the course of eleven weeks, the creaming behavior, particle size, melting behavior and polymorphism were characterized. The dispersions stabilized with solely β-lg exhibited a slight increase in particle size, whereas a decrease in size was found when PLs were added. Our results indicate that mass transport phenomena between TAG droplets and particles took place during storage. This migration of TAG molecules changed the composition and size distribution of the dispersed phase, especially at higher PL concentration (0.1 wt%). In our case, this could be prevented by using a lower concentration of PLs, i.e., 0.05 wt%.","PeriodicalId":10433,"journal":{"name":"Colloids and Interfaces","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47528482","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Continuous Electrophoretic Separation of Charged Dyes in Liquid Foam 液体泡沫中带电染料的连续电泳分离

IF 2.4

Colloids and Interfaces Pub Date : 2023-06-02 DOI: 10.3390/colloids7020044

Matthieu Fauvel, A. Trybala, D. Tseluiko, V. Starov, H. C. H. Bandulasena

{"title":"Continuous Electrophoretic Separation of Charged Dyes in Liquid Foam","authors":"Matthieu Fauvel, A. Trybala, D. Tseluiko, V. Starov, H. C. H. Bandulasena","doi":"10.3390/colloids7020044","DOIUrl":"https://doi.org/10.3390/colloids7020044","url":null,"abstract":"A novel electrophoretic separation technique is presented, where continuous electrophoretic separation is demonstrated using free flowing liquid foams. Continuous foam electrophoresis combines the principle of capillary electrophoresis and interactions between analytes and the electrical double layer, with the ability of Free Flow Electrophoresis to continuously separate and recover analytes automatically. A liquid foam is used to provide a network of deformable micro and nano channels with a high surface area, presenting a novel platform for electrophoresis, where interfacial phenomena could be exploited to modify analyte migration. The main purpose of this paper is to present a proof-of-concept study and provide fundamental understanding of a complex foam system in continuous separation mode, i.e., flowing liquid foam under an external electric field with electrophoresis and chemical reactions at the electrodes continuously changing the system. Liquid foam is generated using a mixture of anionic and non-ionic surfactants and pumped through a microfluidic separation chamber between two electrodes. The effectiveness of the device is demonstrated using a dye mixture containing a neutral dye and an anionic dye. At the outlet, the foam is separated and collected into five fractions which are individually probed for the concentration of the two dyes used. The anionic dye was concentrated up to 1.75 (±0.05) times the initial concentration in a select outlet, while the neutral dye concentration remained unchanged in all outlets, demonstrating the potential for electrophoretic foam separations.","PeriodicalId":10433,"journal":{"name":"Colloids and Interfaces","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42581639","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Influence of Wet Film Thickness on the Functional Applications of Biopolymers in Paper Conservation 湿膜厚度对生物聚合物在纸张保护中的功能应用的影响

IF 2.4

Colloids and Interfaces Pub Date : 2023-05-30 DOI: 10.3390/colloids7020043

Gabriela Aleksić, T. Cigula, Marina Vukoje, Katarina Itrić Ivanda

引用次数: 0

Amplification of SERS Signal of Methotrexate Using Beta-Cyclodextrin Modified Silver Nanoparticles β -环糊精修饰纳米银对甲氨蝶呤SERS信号的放大研究

IF 2.4

Colloids and Interfaces Pub Date : 2023-05-26 DOI: 10.3390/colloids7020042

N. E. Markina, I. Goryacheva, A. Markin

{"title":"Amplification of SERS Signal of Methotrexate Using Beta-Cyclodextrin Modified Silver Nanoparticles","authors":"N. E. Markina, I. Goryacheva, A. Markin","doi":"10.3390/colloids7020042","DOIUrl":"https://doi.org/10.3390/colloids7020042","url":null,"abstract":"The paper describes the use of native β-cyclodextrin (CD) for the modification of silver nanoparticles (AgNPs) in order to improve the determination of the anticancer drug methotrexate (MTX) using surface-enhanced Raman spectroscopy (SERS). A control experiment with unmodified AgNPs showed that the strong SERS signal of MTX can only be achieved in alkaline media. However, competitive interactions and the strong background signal of human body fluid components significantly challenge MTX determination in real samples. While previous reports propose the use of thorough sample pretreatment (e.g., solid phase extraction), the application of CD-modified AgNPs increases the SERS signal of MTX in neutral media by seven times which enables simplifying the analysis and improving its accuracy by reducing the influence of endogenous components of body fluids. A detailed study of the synthesis conditions (CD concentration and reaction time) and SERS registration conditions (pH, NaCl concentration, dilution of urine samples) was performed to maximize the analytical signal and signal-to-noise ratio. The final assay was tested for MTX determination in artificially spiked samples of real human urine. The results demonstrated that MTX can be determined within the concentration range suitable for therapeutic drug monitoring (20–300 μg mL−1) with satisfactory precision (6–15% RSD), accuracy (95–111% apparent recovery), and limit of detection (0.3 μg mL−1).","PeriodicalId":10433,"journal":{"name":"Colloids and Interfaces","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46869282","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Experimental and Machine Learning Studies on Chitosan-Polyacrylamide Copolymers for Selective Separation of Metal Sulfides in the Froth Flotation Process 壳聚糖-聚丙烯酰胺共聚物在泡沫浮选过程中选择性分离金属硫化物的实验和机器学习研究

IF 2.4

Colloids and Interfaces Pub Date : 2023-05-17 DOI: 10.3390/colloids7020041

K. Monyake, Taihao Han, D. Ali, L. Alagha, Aditya Kumar

{"title":"Experimental and Machine Learning Studies on Chitosan-Polyacrylamide Copolymers for Selective Separation of Metal Sulfides in the Froth Flotation Process","authors":"K. Monyake, Taihao Han, D. Ali, L. Alagha, Aditya Kumar","doi":"10.3390/colloids7020041","DOIUrl":"https://doi.org/10.3390/colloids7020041","url":null,"abstract":"The froth flotation process is extensively used for the selective separation of valuable base metal sulfides from uneconomic associated minerals. However, in this complex multiphase process, various parameters need to be optimized to ensure separation selectivity and peak performance. In this study, two machine learning (ML) models, artificial neural network (ANN) and random forests (RF), were used to predict the efficiency of in-house synthesized chitosan-polyacrylamide copolymers (C-PAMs) in the depression of iron sulfide minerals (i.e., pyrite) while valuable base metal sulfides (i.e., galena and chalcopyrite) were floated using nine flotation variables as inputs to the models. The prediction performance of the models was rigorously evaluated based on the coefficient of determination (R2) and the root-mean-square error (RMSE). The results showed that the RF model was able to produce high-fidelity predictions of the depression of pyrite once thoroughly trained as compared to ANN. With the RF model, the overall R2 and RMSE values were 0.88 and 4.38 for the training phase, respectively, and R2 of 0.90 and RMSE of 3.78 for the testing phase. As for the ANN, during the training phase, the overall R2 and RMSE were 0.76 and 4.75, respectively, and during the testing phase, the R2 and RMSE were 0.65 and 5.42, respectively. Additionally, fundamental investigations on the surface chemistry of C-PAMs at the mineral–water interface were conducted to give fundamental insights into the behavior of different metal sulfides during the flotation process. C-PAM was found to strongly adsorb on pyrite as compared to galena and chalcopyrite through zeta potential, X-ray photoelectron spectroscopy (XPS), and adsorption density measurements. XPS tests suggested that the adsorption mechanism of C-PAM on pyrite was through chemisorption of the amine and amide groups of the polymer.","PeriodicalId":10433,"journal":{"name":"Colloids and Interfaces","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43903120","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Morphological Diversity in Diblock Copolymer Solutions: A Molecular Dynamics Study 二嵌段共聚物溶液的形态多样性:分子动力学研究

IF 2.4

Colloids and Interfaces Pub Date : 2023-05-09 DOI: 10.3390/colloids7020040

Senyuan Liu, R. Sureshkumar

{"title":"Morphological Diversity in Diblock Copolymer Solutions: A Molecular Dynamics Study","authors":"Senyuan Liu, R. Sureshkumar","doi":"10.3390/colloids7020040","DOIUrl":"https://doi.org/10.3390/colloids7020040","url":null,"abstract":"Coarse-grained molecular dynamics simulations that incorporate explicit water-mediated hydrophilic/hydrophobic interactions are employed to track spatiotemporal evolution of diblock copolymer aggregation in initially homogeneous solutions. A phase portrait of the observed morphologies and their quantitative geometric features such as aggregation numbers, packing parameters, and radial distribution functions of solvent/monomers are presented. Energetic and entropic measures relevant to self-assembly such as specific solvent accessible surface area (SASA) and probability distribution functions (pdfs) of segmental stretch of copolymer chains are analyzed. The simulations qualitatively capture experimentally observed morphological diversity in diblock copolymer solutions. Topologically simpler structures predicted include spherical micelles, vesicles (polymersomes), lamellae (bilayers), linear wormlike micelles, and tori. More complex morphologies observed for larger chain lengths and nearly symmetric copolymer compositions include branched wormlike micelles with Y-shaped junctions and cylindrical micelle networks. For larger concentrations, vesicle strands, held together by hydrogen bonds, and “giant” composite aggregates that consist of lamellar, mixed hydrophobic/hydrophilic regions and percolating water cores are predicted. All structures are dynamic and exhibit diffuse domain boundaries. Morphology transitions across topologically simpler structures can be rationalized based on specific SASA measurements. PDFs of segmental stretch within vesicular assemblies appear to follow a log-normal distribution conducive for maximizing configuration entropy.","PeriodicalId":10433,"journal":{"name":"Colloids and Interfaces","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47135847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The Effects of Viscosity and Capillarity on Nonequilibrium Distribution of Gas Bubbles in Swelling Liquid–Gas Solution 粘度和毛细作用对膨胀液-气溶液中气泡不平衡分布的影响

IF 2.4

Colloids and Interfaces Pub Date : 2023-05-05 DOI: 10.3390/colloids7020039

A. Shchekin, A. Kuchma, E. Aksenova

引用次数: 0

Superspreading Surfactant on Hydrophobic Porous Substrates 疏水性多孔基质上的超扩散表面活性剂

IF 2.4

Colloids and Interfaces Pub Date : 2023-05-04 DOI: 10.3390/colloids7020038

Wellington Tafireyi, Max Littlewood, H. C. H. Bandulasena, A. Trybala, V. Starov

引用次数: 0

Rheology of Pickering Emulsions Stabilized and Thickened by Cellulose Nanocrystals over Broad Ranges of Oil and Nanocrystal Concentrations 纤维素纳米晶体在大范围油和纳米晶体浓度下稳定和增稠皮克林乳状液的流变学