Total Pore Surface Research Articles

Insights into the adsorption of emerging organic contaminant by low-cost readily separable modified jute fiber.

A high-efficiency biosorbent based on the low-priced jute fiber was developed, characterized, and applied to remove the emerging organic contaminant diclofenac from aqueous solutions. Jute fiber was treated by NaOH (named AJF) followed by graftingdifferent amounts of trimethyl[3-(trimethoxysilyl) propyl] ammonium chloride (named AJF-TTSAC). The composition, morphology, porosity, and adsorption features of the neat and modified jute fiber were evaluated and compared. The surface of neat JF was smooth, nonporous, and free of cracks. NaOH treatment increased the fibrillation, created cracks and grooves, and increased the oxygen content, total pore volume, and surface area. In comparison to AJF, grafting TTSAC filled in the crevices, grooves, and spaces between fibrillates, and decreased the total pore volume and surface area. The adsorption of diclofenac by the neat and modified JF occurred at highly acidic pHo and peaked at pHo 3. Among the neat and modified JF, AJF-TTSAC5 was the most efficient followed by AJF. The efficiency of AJF and AJF-TTSAC5 was highest using 1.00 g/L, at 35 °C and was not affected by the presence of NaCl. The Elovich, pseudo-first-order, and pseudo-second-order models described the adsorption kinetic satisfactorily with the marginal advantage of Elovich for AJF and pseudo-second-order for AJF-TTSAC5. The isotherm study exposed the multilayer and physisorption nature of the adsorption of diclofenac onto AJF and AJF-TTSAC5. The Langmuir monolayer saturation capacity of AJF-TTSAC5 was 37.43 mg/g which revealed its great potential relative to other adsorbents in the literature. The AJF and AJF-TTSAC5 were easily regenerated using distilled water and kept good performance for 5 repetitive cycles.

Incorporation of composite metal-PVP derived carbon membranes for the percrystallisation of salt water

In this research using supported metal‑carbon membranes in a membrane percrystallisation application, we investigated the influence of metal ions on the formation of carbon during carbon membrane synthesis by combining polyvinylpyrrolidone (PVP) with various metal compounds, including zinc, potassium, barium, sodium, magnesium, calcium, and strontium, through calcination at 700 °C in a nitrogen atmosphere for the first time. These carbon membranes were then subjected to continuous percrystallisation experiments to produce dry salt crystals from salt solutions. The feed solution (3.5, 10, 20 wt% of salt) were used at 30, 50, and 70 °C for the performance evaluation. Intriguingly, the addition of metal elements to the PVP solution resulted in an enhancement in the total pore volume and surface area of the resulting carbon membranes. The PVP-Zn precursor exhibited the highest increase with a maximum improvement of 99 fold. Moreover, when compared to the PVP membranes alone, the composite membranes also exhibited higher fluxes. Among the tested composite carbon membranes, PVP-Ca, PVP-Zn, and PVP-Mg demonstrated the highest flux values, reaching an impressive 55 kg.m−2.h−1. Additionally, these membranes exhibited self-elimination, where salt was effectively removed from the membrane surface during percrystallisation testing. Thus, these membranes have the potential to be employed in desalination applications.

From Hansen solubility parameters to new anti-icing, viscoelastic sponges of terpolymer of tetrafluoroethylene, vinylidenefluoride, and hexafluoropropylene (THV)

THV, a relatively new hydrophobic polymer, has found wide application from explosives to sensors. Therefore, we decided to determine its Hansen Solubility Parameters (HSP) – one of the most important parameters in polymers processing. Studied 41 liquids can be divided into four groups: very good solvents (1), causing gelation (2) causing soaking or color change (3), and inert (4) and HSP values were calculated. We also proposed green chemistry solvents for THV. At the next stage, two solvents from group 1, and two from group 2, and their mixtures, were selected to determine the effect of a solvent on the THV sponge properties. The sponges were characterized by total pore volumes, porosity, mechanical properties, and surface morphology. Moreover, thermal, and anti-icing properties were studied for different film thicknesses. This holistic approach, together with a theoretical description of the icing process via a dynamic growth angle model, makes it possible to relate the sponge morphology to thermal, mechanical, hydrophobic, and anti-icing properties, showing that the studied sponges are strongly hydrophobic or superhydrophobic with a water contact angle (WCA) as large as 160° for THVAC. Considering anti-icing properties, total freezing time, delaying of recalescence, and possible ice removal by wind or vibration, the sponge obtained from the mixture of DMF and acetone (THVDMFAC) seems to be optimal. This sponge has the highest Young’s modulus, high thermal stability, and anti-freezing properties thus, it can be successfully applied in anti-icing covers in, for example, wind turbine blades.

Pore Structure and Fractal Characteristics of the Middle and Upper Permian Dalong and Gufeng Shale Reservoirs, Western Hubei Province, South China

The Middle and Upper Permian Dalong and Gufeng Formations in South China have recently been considered as potential gas-producing shales. However, their pore structure characteristics remain poorly understood. To investigate the pore structure and fractal characteristics of the pores in these two formations, a suite of shale samples from the Dalong and Gufeng Formations in the western Hubei Province, South China were analyzed by multiple techniques, namely, TOC content, X-ray diffraction (XRD) mineralogy analysis, optical microscopy observations, major elemental analysis, field emission-scanning electron microscopy (FE-SEM), and low-pressure gas adsorption measurements (N2 and CO2). The identified major shale lithofacies include siliceous mudstone, carbonaceous mudstone, argillaceous-siliceous mixed mudstone, and calcareous-siliceous mixed mudstone. SEM images show that the dominant pore types include the pores between brittle minerals, slit-shaped pores between clay sheets, and secondary organic matter (OM) pores within solid bitumen. The pore size distribution is dominated by micropores and mesopores (<30 nm), which are the major contributors to total pore volume and surface area for the Dalong and Gufeng Formations. Based on the Frenkel–Halsey–Hill (FHH) method, fractal dimensions (D1, D2) calculated from the nitrogen adsorption data have a range of from 2.489 to 2.772 (D1) and from 2.658 to 2.963 (D2), and are higher in the Gufeng Formation (average TOC = 8.3 wt.%) due to a higher TOC content comparing to the Dalong Formation (average TOC = 6.2 wt.%). The pore development and fractal characteristics are primarily controlled by organic matter (OM), carbonate minerals, and clay minerals for both the Dalong and Gufeng Formations. Shale samples with high TOC content, low carbonate content, and high clay content tend to develop more heterogeneous micropores and mesopores, which is ascribed to the generation of clay-related and OM-hosted pores, along with the destruction of primary pores by pore-filling carbonate cements.

Effects of chicken manure‐modified biochar on the adsorption capacity of tetracycline and abundance of antibiotic resistance genes in soil

AbstractLarge quantities of livestock manure not only occupy farmland but also serve as the primary source of antibiotics and antibiotic resistance genes (ARGs) in agricultural soil. To enhance the resource utilization of animal manure and mitigate ecological risks associated with antibiotics in agroecosystems, chicken manure was used as a raw material for biochar production. The manure derived biochar (MB) was modified with an alkali–acid two‐step modification process. The results showed that the total pore volume and surface area of alkali–acid modified MB (AMMB) was significantly increased about three and five times, respectively after modification. The SEM images showed that the surface of AMMB had a more regular and clearer structure with fewer impurities. The improvement of surface properties of AMMB significantly increased its adsorbing capacity of tetracycline in the soil. The adsorption kinetics of tetracycline by AMMB were better fitted by the pseudo‐second‐order kinetic model, suggesting that the adsorption of tetracycline on biochar followed the process of chemisorption. The adsorption mechanisms mainly involved the pore filling, hydrophobic effect, and π–π EDA interaction. Moreover, after a 60 days amendment of AMMB, the total relative abundances (RAs) of tested tetracycline resistance genes (TRGs) in soil decreased significantly, which suggested that AMMB can be a potential material to reduce risks of antibiotics and its resistance genes.

Characterization and optimization of pore structure and water adsorption capacity in pinecone-derived activated carbon by steam activation

Activated carbon, due to its notable porosity and cost-effectiveness, emerges as a promising desiccant material. This research delves into the utilization of pinecones as a precursor for the production of activated carbon through steam activation. The resultant activated carbon samples presented a porous structure and exhibited a high water adsorption capacity, with the highest adsorption capacity reaching 0.35 kg/kg, placing it in competition with commercial silica gel. Various experimental parameters were systematically manipulated during the production process to optimize both the pore structure and water adsorption capacity of the activated carbon samples. Elevating the carbonization temperature from 700 °C to 900 °C proved effective in enhancing pore distribution and elevating water adsorption capacity. Furthermore, higher activation temperatures contributed to the formation of additional mesopores and macropores, possibly attributable to micropore enlargement through steam activation. Nevertheless, these elevated activation temperatures resulted in an undesired increment in mesopores concerning water adsorption. The extension of activation time led to increased micropore formation, albeit with concurrent disruption, culminating in heightened total pore volume and surface area. This extension shifted the water adsorption-desorption isotherm to higher relative pressure ranges, accompanied by a larger hysteresis loop. Moreover, an increased steam mass flow rate was found to enhance the pore structure and water adsorption capacity of the activated carbon. The activated carbons exhibited sigmoid-shaped isotherms, signifying their suitability for both open-cycle and closed-cycle adsorption systems.

Experimental Study on Properties of Syngas, Tar, and Biochar Derived from Different Gasification Methods

Biomass gasification technology is a clean and renewable energy utilization approach. Understanding the evolution of gasification product properties is crucial to achieving carbon neutrality goals. A fixed-bed reactor is employed for the biomass gasification with CO2 in this study. Various methodologies have been conducted to characterize the syngas, tar, and biochar produced from the electric gasification (EG) and microwave gasification (MG) of oak and corn stalk samples at different temperatures. When gasifying the same biomass at the same temperature, the syngas yield of MG is generally 3–7% higher than that of EG, and the difference increases with decreasing temperature. The biochar yield of MG is 3–6% higher than that of EG. EG produces more tar at 600–800 °C. The yield of syngas increases as the gasification temperature rises from 600 to 1000 °C, but that of tar and biochar falls. The syngas mainly comprises H2, CH4, CO, and CO2. MG produces 8–15% higher CO content and 2.5–3.5% higher H2 content than EG. This is due to different heating mechanisms. The net calorific value of syngas increases with temperature, reaching a maximum of 11.61 MJ m−3 at 1000 °C for syngas from corn stalk MG. When the temperature rises from 600 to 1000 °C, more primary tars are converted into polycyclic aromatic hydrocarbons (PAHs). At 900 °C, corn stalk biochar from MG has a maximum specific total pore volume (0.62 cm3 g−1), surface area (525.87 m2 g−1), and average pore diameter (4.18 nm). The intensities of the characteristic peaks of biochar functional groups decrease gradually. The heating method has little effect on the types of functional groups.

Excellent Performance and Feasible Mechanism of ErOx-Boosted MnOx-Modified Biochars Derived from Sewage Sludge and Rice Straw for Formaldehyde Elimination: In Situ DRIFTS and DFT

To avoid resource waste and environmental pollution, a chain of ErOx-boosted MnOx-modified biochars derived from rice straw and sewage sludge (EryMn1-y/BACs, where biochars derived from rice straw and sewage sludge were defined as BACs) were manufactured for formaldehyde (HCHO) elimination. The optimal 15%Er0.5Mn0.5/BAC achieved a 97.2% HCHO removal efficiency at 220 °C and exhibited favorable EHCHO and thermal stability in a wide temperature window between 180 and 380 °C. The curbed influences of H2O and SO2 offset the boosting effect of O2 in a certain range. Er–Mn bimetallic-modified BACs offered a superior HCHO removal performance compared with that of BACs boosted using Er or Mn separately, owing to the synergistic effect of ErOx and MnOx conducive to improving the samples’ total pore volume and surface area, surface active oxygen species, promoting redox ability, and inhibiting the crystallization of MnOx. Moreover, the support’s hierarchical porous structure not only expedited the diffusion and mass transfer of reactants and their products but also elevated the approachability of adsorption and catalytic sites. Notably, these prominent features were partly responsible for the outstanding performance and excellent tolerance to H2O and SO2. Using in situ DRIFTS characterization analysis, it could be inferred that the removal process of HCHO was HCHOad → dioxymethylene (DOM) → formate species → CO2 + H2O, further enhanced with reactive oxygen species. The DFT calculation once again proved the removal process of HCHO and the strengthening effect of Er doping. Furthermore, the optimal catalytic performance of 15%Er0.5Mn0.5/BAC demonstrated its vast potential for practical applications.

In-situ biofabrication of bacterial nanocellulose (BNC)/graphene oxide (GO) nano-biocomposite and study of its cationic dyes adsorption properties

In the present study, bacterial nanocellulose/graphene oxide nano-biocomposites (BNC-GO-NBCs) were fabricated by Komagataeibacter saccharivorans NUWB1 using an in-situ method involving three time-dependent approaches. Physicochemical studies showed that the chosen dried BNC-GO-NBC possessed a three-dimensional interconnected porous structure of BNC with GO layers embedded within the BNC fibrils. BNC-GO-NBC had a crystallinity index of 74.21 %, higher thermostability up to 380 °C and could withstand a tensile load of 84.72 MPa. N2 adsorption-desorption isotherm of the BNC-GO-NBC was found to be of type IV, suggesting a mesoporous type structure with a total pore volume and surface area of 6.232e-04 cc g−1 and 10.498 m2. BNC-GO-NBC exhibited remarkable adsorption capacity for two cationic dyes, Rhodamine B (RhB) and Acridine Orange (AO), and the adsorption data conformed well to the Langmuir isotherm (R2 = 0.99) and pseudo-second-order model. Thermodynamic studies indicated that the adsorption process was spontaneous and endothermic. Additionally, the BNC-GO-NBC displayed the potential for regeneration, with the ability to be recycled up to five times. Further, the antibacterial activity, cell cytotoxicity and oxidative stress assays of the BNC-GO-NBC revealed its non-cytotoxic nature. The findings of the present investigation evidently suggest the potentiality of BNC-GO-NBC in the application of dye adsorption and other environmental applications.

Investigating the porosity of Enceladus

ABSTRACT The interior of Enceladus, a medium-sized icy moon of Saturn hosts hydrothermal activity and exhibits tidal heating and related geyser-like activity. There are major disagreements in the existing literature on the porosity of the interior due to the different theoretical assumptions on which porosity related calculations are based. We present an application of experimental equations – derived for the Earth – for icy planetary objects and Enceladus in particular. We chose a set of boundary values for our initial parameters from measured porosity values of chondrite samples as references and calculated the porosity related values of Enceladus using various approaches. We present a comprehensive investigation of the effects of using these different porosity calculation methods on icy moons. With our most realistic approach, we also calculated the same values for the Earth and Mars for comparison. Our result for Enceladus is a minimum porosity of about 5 per cent at the centre of the body. For the total pore volume, we estimated 1.51 · 107 km3 for Enceladus, 2.11 · 108 km3 for the Earth and 1.62 · 108 km3 for Mars. Using the same method, we estimated the total pore surface area. From this, we derived that the pore surface under a given 1 km2 area of the surface on Enceladus is about 1.37 · 109 km2, while for the Earth this value is only 5.07 · 107 km2.

Interlayer adhesion of 3D printed concrete: Influence of layer stacked vertically

3D printed concrete is an emerging intelligent construction method, and it has been attracting an exponential attention in this sector. However, one of the major issues in printed concrete is the cold joint between the neighbor layers. In this study, an experimental study on the relation between the number of stacked layers vertically and the interlayer adhesion of 3D printed element was conducted. Splitting method was carried out to test the interlayer bond strength, mercury intrusion porosimetry (MIP) and X-ray computed tomography (X-CT) scanner were used to investigate the pore structure of the interlayer zone. The experimental results indicated that a markable influence of the stacked layers vertically on the interlayer adhesion is found. The interlayer bond strength in the middle interface of the printed element is higher than that of the upper and bottom interfaces, especially the bond strength in the bottom interface is the least. Such result is also reflected in the results of the MIP test: the lower total pore volume and total pore surface area existed in the middle interfaces. The X-CT results showed that a large number of elongated and flat pores present in the interlayer zone, the pores in the bottom interface tend to be interconnected or continuous due to the pressure of upper printed layers. An empirical model was proposed to account for the formation of the irregular pore and the change of bond strengths between the vertical neighbored layers of 3D printed element.

Micro-meso-macroscale correlation mechanism of red-bed soft rocks failure within static water based on energy analysis

The purpose of the present study is to fundamentally investigate the micro-meso-macroscale correlation mechanism of red-bed soft rocks failure within static water, based on energy analysis. Through a series of experimental studies, changes in the micro-meso-macroscale characteristics of the rocks were characterised by measuring ion concentrations in and pH of water, the pore structure and crack propagation. Based on the experimental measurements, theoretical modelling of micro-meso-macroscale energy conservation was carried out to determine the micro-meso-macroscale correlation mechanism of red-bed soft rocks failure. The results show that the microscale dominant effect of red-bed soft rocks is determined as chemical effects. The failure mechanism of red-bed soft rocks under static water saturation involves chemical, physical and mechanical dominant effects at the micro-meso-macroscale. It was demonstrated that the dominant chemical effect of clay minerals and water comprises a series of chemical energy changes in the microscale water–rock interface. This can induce the energy changes in both mesophysical and macromechanical levels. During the first month after the water saturation, there was a significant decrease in Na+ and K+ concentrations in aqueous solution, whereas there was little change in Ca+ and Mg2+ concentrations. The scanning electron microscope (SEM) images indicated an obvious change in microstructure of the red-bed soft rocks after 3 months of water saturation. A decrease in pore number and increase in total pore surface area could be seen after 6 months of water saturation. Furthermore, the theoretical results suggest that chemical effects at the microscale dominate the softening process of the rocks. During the water–rock interaction, nearly 80% of the energy dissipation results from the microscale change, and the meso-macroscale change accounts for the remaining 20%. As a uniform measure of material evolution, energy can correlate the micro-meso-macro dominant effect of red-bed soft rocks softening appropriately.

A study of the association involving pore characteristics and compressive strength of cement pastes incorporating fine fly ash

The evaluation of mechanical properties in materials derived from cements incorporating ultrafine fly ash was performed. An examination of the influences of curing time, fly ash concentration, and particle size on the compressive strength of materials derived from cements was executed. Upon the integration of ultrafine fly ash into materials derived from cements, the pore structure was scrutinized using the mercury intrusion technique, and the impact of fly ash concentration and particle size on diverse pore structure parameters was investigated. According to the findings, the quantity of macropores in materials derived from cements progressively diminished with the rise in fly ash concentration, and the porosity consistently decreased with the extension of curing time, culminating in an elevation of compressive strength. The proportion of gel pores in materials derived from cements contracted with the increment in fly ash concentration, resulting in a decline in compressive strength. Fly ash particles of reduced dimensions exhibit heightened compressive strength due to the diminution in particle size. Employing fractal theory, the fractal dimension of the pore surface in materials derived from cements was ascertained, and an outstanding correlation between the fractal dimension and the total pore surface area was discovered. Grounded in the connection concerning the compressive strength of materials derived from cements and assorted pore structure parameters, a suitable relationship model has been devised between the total pore volume, transitional pore volume, and compressive strength. At the same time, a fitting scope of the model had been determined.

Relationship between fractal feature and compressive strength of fly ash-cement composite cementitious materials

Microscopic pore structure and compressive strength of fly ash-cement composite cementitious materials at 20 °C and 60 °C measured by mercury intrusion porosimetry and compressive strength test. Microscopic pore structure was analyzed from porosity, pore volume, total pore surface area, average pore diameter, median pore diameter, most probable diameter, threshold diameter and fractal feature. The fractal dimensions of each specimen were calculated by Menger Sponge. The regression analysis between fractal dimension and pore structure parameters were fitted by linear function, quadratic polynomial function, power function and exponential function, respectively. Eventually, the relationship between pores structure and compressive strength was characterize by the mathematical model between the optimal comprehensive parameter of pores structure and compressive strength. And the T-test and F-test were used to reveal the significance of the regression parameter and function. Research results showed that the fractal curves of all specimens consist of four segments. The pores have obvious fractal features in Region I and Region IV, while presented no-fractal feature in Region II and Region III. In Region I and Region IV, fractal dimension followed the exponential function with average pore diameter, median pore diameter, most probable diameter and threshold diameter, consistent with quadratic polynomial function with porosity, pore area and pore volume, and accords with the positive power exponential function with compressive strength. Thus, the morphology of hierarchical aggregates expressed by fractal dimension can reflect the relationship compressive strength and pore structure in fly ash-cement composite cementitious materials more directly.

Effect of Low Nesquehonite Addition on the Hydration Product and Pore Structure of Reactive Magnesia Paste.

Reactive magnesia cement is considered an eco-efficient binder due to its low synthesis temperature and CO2 absorption properties. However, the hydration of pure MgO-H2O mixtures cannot produce strong Mg(OH)2 pastes. In this study, nesquehonite (Nes, MgCO3·3H2O) was added to the MgO-H2O system to improve its strength properties, and its hydration products and pore structure were analyzed. The experimental results showed that the hydration product changed from small plate-like Mg(OH)2 crystals to interlaced sheet-like crystals after the addition of a small amount of Nes. The porosity increased from 36.3% to 64.6%, and the total pore surface area increased from 4.6 to 118.5 m2/g. At the same time, most of the pores decreased in size from the micron scale to the nanometer scale, which indicated that Nes had a positive effect on improving the pore structure and enhancing the compressive strength. Combined with an X-ray diffractometer (XRD), a Fourier transform infrared spectrometer (FTIR), and a simultaneous thermal analyzer (TG/DSC), the hydration product of the sample after Nes addition could be described as xMgCO3·Mg(OH)2·yH2O. When Nes was added at 7.87 and 14.35 wt%, the x-values in the chemical formula of the hydration products were 0.025 and 0.048, respectively. These small x-values resulted in lattice and property parameters of the hydration products that were similar to those of Mg(OH)2.

Perspectives of Gas Adsorption and Storage in Kerogens and Shales

Shale gas from unconventional resources will contribute to meeting the energy demand during the transition to a net-zero carbon economy. In this minireview, the current status of understanding methane adsorption on kerogens and shales is discussed in relation to methane storage capacity. Standard subcritical adsorption studies provide characterization data (micropore volumes, total pore volumes, surface areas, and pore size distributions) for the porous structures of shales and kerogens. However, supercritical methane adsorption measurements under simulated geological conditions are necessary to assess realistic methane adsorption storage capacities. Supercritical methane adsorption on shale and shale components (kerogens and clays) under high pressure and temperature conditions that simulated geological conditions is compared. Kerogen structural characteristics are discussed in relation to supercritical methane isotherms and isobars. The contribution of adsorbed methane gas relative to “free” or compressed gas to the total gas stored in shale is considered. The importance of kerogens in both storage of the adsorbed phase and as the source of methane is highlighted, and the areas where knowledge and understanding are deficient are identified, in particular, the relationship of kerogen type and maturity with supercritical methane adsorption under simulated geological conditions. The competitive adsorption of water on methane capacity is also an area where more detailed studies are necessary. These are challenges to address gaps in the current knowledge and understanding, which require future research.

Effect of thermal fatigue on mechanical properties and microstructure of concrete in constant ambient humidity

The daily and annual temperature differences in mid and high latitudes areas vary greatly, which leads to thermal fatigue deterioration of concrete. The deterioration of concrete properties can also be generated by the cyclic change of humidity in concrete. In the experiment, the thermal fatigue tests of concrete with two strength grades were carried out at the temperature difference of 20 °C, 30 °C, and 40 °C (the initial temperature is 20 °C) under the condition of constant ambient humidity. The macroscopic properties change of concrete such as compressive strength and splitting tensile strength were measured. The microstructure changes of concrete were determined by ultrasonic nondestructive testing technique and mercury intrusion test. The results indicated that thermal fatigue has obvious deterioration effect on concrete. With the increase of temperature difference and cycle number, the strength of concrete decreased dramatically and the decrease of C40 concrete was greater than that of C25 concrete. The splitting tensile strength was more sensitive to thermal fatigue than compressive strength. The ultrasonic wave velocity gradually decreased and the damage factor increased, indicating the internal crack defects of concrete increased. At the same temperature difference, the porosity, total pore volume, average pore diameter, medium pore diameter, and the most probable pore diameter of concrete increased gradually with the increase of the cycle number, while the total pore surface area decreased. The pore structure showed the characteristics of coarsening and the trend of deterioration. The porosity of C40 concrete was less than that of C25 concrete, but the relative change value of porosity was larger, which reveals the internal reason for the strength damage of concrete under thermal fatigue at the microscopic level.

High Surface Area Silica Particles Using Anionic Surfactant Template Prepared by One-step Spray Drying System for Dye Removal Application

This study reported the effect of sodium lauryl sulfate (SLS) as a template on silica morphology and its properties. The precursor was prepared by producing silica nanofluid by the sol-gel method and mixed with various SLS concentrations. After that, the precursor was spray-dried to generate silica powder. An increase in SLS concentration up to 2 critical micelle concentration (CMC) indicates an increase in the silica particle size from 2.12 μm in untemplated silica particles to 2.58 μm. On the other hand, when the SLS concentration increases to 3 CMC, the particle size decreases to 2.19 μm. A significant increase in total pore volume and surface area is obtained for silica particles synthesized at least at the SLS concentration of 2 CMC, around eight higher volumes than without SLS addition. In addition, they have a macropore compared to silica particles synthesized without SLS addition that only exhibits mesopore. The surface area was 1,011 m2/g for the SLS concentration at 3 CMC, whereas the silica without SLS has only a surface area of 131 m2/g. The SLS concentration at 2 CMC or higher leads to a significant increase in its physical properties because the micelle formation is enough for sacrificed template formation. Methylene blue solution was used as an adsorbate for evaluating the dye adsorption capacity that followed the Langmuir isothermal adsorption model. The highest theoretical maximum monolayer adsorption capacity was 142.9 mg/g, obtained by silica adsorbent with the SLS concentration at 3 CMC.

Influence of sound and calcination temperature on the fabrication of TiO2-based photocatalysts and their photoactivity for H2 production

This work evaluates the influence of sound and calcination temperature on the synthesis of TiO2-based photocatalysts and designated IDs as TiO2_473, TiO2_623, TiO2_473HS, TiO2_623HS, TiO2_473QB, and TiO2_623QB. All designated TiO2-based photocatalysts were synthesized using the precipitation technique in the absence and presence of sound (409 and 274 Hz), and calcination at 473 and 623 K. Various instrumental techniques, including Thermogravimetric Analysis (TGA), Adsorption and N2 desorption, X-ray Diffraction (XRD), Diffuse Reflectance Spectroscopy (DRS), Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM), were used to thoroughly characterize the as developed TiO2-based photocatalysts. An increase was observed in the relative intensity of the diffraction peaks with the increase in the calcination temperature in the presence or absence of sound. However, at 409 Hz, the larger crystallite size was observed for all tested fractions. Furthermore, the increase in the calcination temperature promoted the sintering of the mesopores, decreasing total pore volumes and surface area and increasing the average pore diameter. As developed TiO2-based photocatalysts were deployed to produce H2 via reforming an aqueous solution of methanol and ethanol under the UV region. The performance of photocatalysts in the presence of ethanol used as a sacrificial agent in the split of water reaction was unquestionably more relevant than methanol. The following order of H2 production from ethanol was observed, TiO2_473QB > TiO2_473HS > TiO2_623QB > TiO2_623HS > TiO2_473 > TiO2_623.

Characterisation of hydrogels and aerogels as carriers for sea buckthorn pomace extract

SummaryIn this study, aerogels were prepared from kognac glucomannan (KG) or whey proteins loaded with bioactive sea buckthorn pomace extract. KG was diacetylated with Na2CO3 (0.1; 0.2; 0.3; 0.4 m) resulting hydrogel formation that were further freeze‐dried to obtain an aerogel structure. Whey protein aerogels were prepared by removing pore fluid from alcogels using supercritical CO2 drying. Produced aerogels evaluated for microstructure, porosity, specific surface area, absorption capacity, encapsulation efficiency and antioxidant capacity of the extract. It was found that higher concentration of alkali induced higher hardness, resilience and elastic modulus values. It was also obtained that pores in the konjac glucomannan aerogels were irregular in shape and a decrease in total pore volume (0.026 to 0.019 cc/g) and surface area (12.39 to 11.40 m2/g) after increasing the carbonate concentration was observed. These aerogels were found to have better encapsulation efficiency properties for sea buckthorn pomace extract (17 to 20%) in comparison to whey protein aerogels (0.05 to 0.36%). Overall, the KG aerogels show potential for applications in the food industry as a carrier of bioactive sea buckthorn pomace extract, while whey proteins must be used in combination with other biopolymers to enhance their bioactive compound loading capacity.