Ethanol Drying Research Articles

Unlocking the electrochemical potential of carbon aerogels: Tailored performance via controlled carbonization and activation process

In this study, Carbon Aerogels (CAs) were prepared by high-temperature supercritical drying (HTSD) in ethanol for supercapacitors (SCs). HTSD eliminates the acetone-liquid CO2 exchange step and offers a time-efficient alternative to traditional liquid CO2 drying methods. This study investigated the effect of varying carbonization temperatures (600, 700, 800, and 900 °C) on resorcinol-formaldehyde aerogel and assessed their impact on structural, morphological, compositional, and surface area properties. Amongst, CA carbonized at 700 °C (CA-7) exhibited superior performance with a specific capacitance (Cs) of 78 F/g, energy density (Ed) of 39 Wh/kg at 2 A/g in 1 M Na2SO4. After KOH activation, CA-7 demonstrated two-fold enhancement in Cs (184 F/g at 2 A/g) and three-fold in Ed (93 Wh/kg) while maintaining 98 % capacitance retention over 7000 cycles. The symmetric aqueous device (ACA\\SSM||ACA\\SSM) exhibited a Cs of 32 F/g, Ed of 25 Wh/kg, Pd of 2308 W/kg, and 88.6 % retention over 2500 cycles at 2.4 V. This research highlights the advantages of HTSD-based CA synthesis and the potential of activated CA and Na2SO4 to achieve high Ed for SCs.

Ultrahighly Sensitive Surface-Enhanced Raman Spectroscopy Film of Silver Nanoparticles Dispersed in Three Dimensions on a Thin Alumina Nanowire Framework.

To develop highly sensitive surface-enhanced Raman spectroscopy (SERS) films, various types of aggregated Ag nanowire (NW) and nanoparticle (NP) complex structures were fabricated using anodic aluminum oxide (AAO) templates and thermal evaporation. Aggregated AgNW structures with numerous tapered nanogaps were fabricated via Ag deposition on aggregated thin alumina nanowires of different lengths. AgNP complex structures were obtained by collapsing vertically aligned thin alumina nanowires 1 μm in length and depositing AgNPs on their tops and sides using surface tension during ethanol drying after functionalization. The Raman signal enhancement factors (EFs) of the samples were evaluated by comparing the SERS signal of the thiophenol (TP) self-assembled monolayer (SAM) on the nanostructures with the Raman signal of neat TP. EFs as high as ~2.3 × 107 were obtained for the optimized aggregated AgNW structure (NW length of 1 μm) and ~3.5 × 107 for the optimized AgNP complex structure. The large EF of the AgNP complex film is attributed mainly to the AgNPs dispersed in three dimensions on the sides of the thin alumina nanowires, strongly implying some important, relevant physics yet to be discovered and also a very promising nanostructure scheme for developing ultrahighly sensitive SERS films with EF > 108.

In vitro evaluation of the impact of a bioceramic root canal sealer on the mechanical properties of tooth roots

Bacground/purposeEndodontically treated teeth are more prone to vertical root fracture with the mechanical property changes to some extent during root canal treatment. This study aimed to investigate the effects of a bioceramic sealer on the mechanical properties of tooth roots. Materials and methodsDentin discs were dried by two different methods (ethanol drying and paper points drying) and then filled with a BC sealer named iRoot SP. SEM and EDS were used to analyze the newly formed minerals in dentin tubules. Elastic modulus and hardness of the secondary dentin in areas proximal to the primary dentin (PD-SD) and areas proximal to canal or iRoot SP (SD-C/SD-iRoot SP) were measured using nanoindentation technique. The compressive strength of roots filled with iRoot SP were tested by compressive loading test. Results(1) Penetration and mineralization: Paper points drying was more conducive to iRoot SP adhesion, spreading and penetration into the dentin tubules than 95% ethanol drying. (2) Micromechanical properties: After filling root canal with iRoot SP, the elastic modulus and hardness of SD-iRoot SP were higher than those of PD-SD (P = 0.001 and P = 0.000). (3) Fracture resistance: The compressive strength of the roots filled with iRoot SP was not significantly different from that of the roots unprepared and unfilled (P = 0.957), but was higher than that of the roots prepared and unfilled (P = 0.009). ConclusionExcessive drying (95% ethanol drying method) is not conducive to the penetration and mineralization of the BC sealer iRoot SP into dentin tubules. The good bioactivity of iRoot SP was responsible for increasing the elastic modulus and hardness of dentin, which strengthened the prepared roots.

Ultra-high specific surface area spherical FePOx/SiO2 aerogel with excellent mechanical properties for the highly selective direct oxidation of CH4 to HCHO

Silica aerogels, characterized by their high porosity and substantial specific surface area, are suitable for applications as catalysts or catalyst supports. The simultaneous attainment of a substantial specific surface area and robust mechanical properties in aerogel materials remains a formidable challenge in material synthesis. Spherical FePOx/SiO2 aerogel materials were synthesized employing a combination of heating reflux, the sol-gel technique, and supercritical ethanol drying. These composites demonstrate an exceptional specific surface area, uniformly dispersed active components, shape controllability, and superior mechanical strength. A noteworthy enhancement in both specific surface area (1175 m2/g) and compressive modulus (7.56 MPa) surpasses many findings reported in extant literature. Under conditions of a reaction temperature at 650 °C and a flow rate of 97.5 mL/min, the HCHO selectivity and yield for 4 wt% FePOx/SiO2 aerogel were 18.3 and 4.2 times, respectively, higher than those of 4 wt% FePOx/SiO2 particles. These composites manifest significant selectivity towards the direct catalytic oxidation of CH4 to HCHO.

S-scheme polyimide aerogel/Bi4O5I2 heterojunction photocatalyst with improved degradation efficiency

Polymer has low migration ability of photogenerated carriers under photoexcitation, which severely limits the photocatalytic application. In this paper, S-type polyimide aerogel/Bi4O5I2 (tPIA/BOI) heterojunction photocatalysts under internal electric field are prepared by supercritical ethanol drying and in-situ solvothermal method. The large surface area (42.381 m2/g) and excellent hydrophilicity (64.11°) can provide more active sites for photocatalytic reactions and better dispersion in solution, which are conducive to the photodegradation of pollutants. The removal rate of tPIA/BOI on tetracycline (TC) aqueous solution can reach 91.3 %, and the photodegradation rate is 31 and 2 times than that of original tPIA and BOI. The internal electric field is generated by the matching of tPIA and BOI, which optimizes the separation and transfer of electron-hole pairs. Besides, the range of light absorption is expanded, thus greatly improving the degradation efficiency of the catalyst.

Ethanol Dry Reforming over Bimetallic Ni‐Containing Catalysts Based on Ceria‐Zirconia for Hydrogen Production

AbstractMixed Ce−Zr oxides with a fluorite structure were synthesized by the solvothermal method in a supercritical medium of isopropanol. The prepared mixed oxides Ce0.5Zr0.5O2 and Ce0.75Zr0.25O2 were used as supports for 5 wt%Ni and bimetallic 2.5 wt%Ni+2.5 wt%Co catalysts. The catalysts were fully characterized (specific surface area, morphology, particle size, phase composition, surface atomic composition) and tested in ethanol dry reforming.The dependences of the conversion of C2H5OH and CO2, the yield of CO and H2, and the H2/CO ratio were estimated. The effect of the supported metals interaction and the effect of Ce/Zr ratio in the support on the catalytic activity were shown. The presence of nickel in the composition of the catalyst is necessary for high catalytic activity. It has been shown that the addition of cobalt cannot contribute to increase the catalytic activity and stability, but helps to decrease the deposition of carbon and significantly reduces the rate of carbon formation during ethanol dry reforming comparing to the monometallic nickel material.

Effect of thermal treatment process on the structure of C/SiO2 composite aerogels

Abstract Carbon/silica composite (C/SiO2) aerogels were synthesized by using tetraethyl orthosilicate, 3-aminopropyltriethoxysilane, trimethylchlorosilane, resorcinol as the silicon and carbon sources, and ethanol as solvent, via the sol–gel process followed by supercritical ethanol drying and thermal treatment. The influence of thermal treatment process on the structure of C/SiO2 composite aerogels was analyzed mainly and measured by Fourier transform infrared spectrometer, X-ray diffraction and nitrogen adsorption–desorption analysis. The results showed that the optimum thermal treatment temperature of C/SiO2 composite aerogels was 1,300°C. With the increase in the thermal treatment time, the linear shrinkage of the composite aerogels increased gradually, and the pore volume, average pore diameter and specific surface area of the composite aerogels increased first and then decreased.

Construction of the novel polyimide/Bi2MoO6-OVs p-n type heterojunction aerogel photocatalysts to enhance the photodegradation on organic pollutants driven by the internal electric field

To photodegrade the organic pollution, the Polyimide/Bi 2 MoO 6 -OVs p-n type aerogel heterojunction photocatalysts with rich pore structure and large surface area were synthesized by chemical amide reaction and supercritical ethanol drying technique successfully. The introduction of oxygen vacancies can be beneficial to the activation of molecular oxygen, which can inhibit photo-generated charge recombination to improve photocatalytic efficiency. Furthermore, the formation of Mo-N chemical bond between the coordination of N atoms of heptazine units and Mo atoms of Bi 2 MoO 6 is confirmed by structure analysis. And the ability of the heterojunction photocatalyst to degrade RhB is improved significantly, which is due to photogenerated electron-hole pairs can be quickly separated under the internal electric field within the space charge region under visible light. Simultaneously, the SEM images show the flocculent PI polymer is coated on the surface of flower-like Bi 2 MoO 6 -OVs microsphere, which can expand the light absorption range and enlarge the surface area. This work provides an innovative perspective to construct polymer aerogel with inorganic materials heterojunction photocatalyst with superior photocatalytic activity. • The introduction of oxygen vacancies to Bi 2 MoO 6 is beneficial to the activation of molecular oxygen. • The flocculent PI polymer coated on the surface of flower-like Bi 2 MoO 6 -OVs microsphere is prepared. • The Mo-N chemical bond formation, rich pore structure and large surface area improve photodegradation efficiency.

Ethanol dehydration performance of three types of commercial-grade zeolite permselective membranes.

Many organic solvents form difficult-to-separate mixtures with water and have an affinity for water, making drying a potential reuse prerequisite. Pervaporation (PV) and vapor permeation (VP) membrane technologies hold promise for energy-efficient solvent drying. Several water-selective membrane materials are commercially available, but performance data is limited, particularly for two recently commercialized membrane materials: chabazite (CHA) and T-type zeolites. In this work, commercial-grade samples of CHA and T-type membranes, along with a NaA zeolite membrane, were evaluated for the removal of water from ethanol. The CHA sample had the highest initial PV water permeance (6820 GPU) and water permselectivity (3430) with 5 wt% water in ethanol at 50 °C. Initial NaA membrane performance was slightly lower (6060 GPU and 3260), while the T-type membrane had the lowest initial permeance and selectivity (4260 GPU and 1090). Performance declined over time, most notably for the NaA membrane, for which water permeance fell over 50% through 39 days of testing. The T-type membrane exhibited the steadiest PV water permeance, but the most variable ethanol permeance. The PV performance of the three membranes largely overlapped the predicted range for T-type membranes. That performance generally exceeds the anticipated ethanol drying performance of non-zeolitic PV membranes but is less than that predicted for NaA and CHA membranes. The present CHA membrane results, along with other recent reports, refine earlier predictions of the ethanol dehydration performance of that type of zeolite. The changing performance with time should be understood to properly design a solvent dehydration system.

3D Photonic Crystals: Synthesis and Drying in Supercritical Ethanol

3D Photonic Crystals: Synthesis and Drying in Supercritical Ethanol

The combination of a new PERVAPTM membrane and molecular sieves enhances the ethanol drying process

A new commercial polyvinyl alcohol (PVA) membrane (PERVAP™ 4100HF) was characterized by scanning electron microscopy (SEM), Fourier-transform infrared (FTIR), and contact angle (CA) goniometer. The separation performance of the membrane for drying ethanol by pervaporation was also investigated and compared with a standard membrane (PERVAP™ 4100) under same operating conditions. The results show that the new membrane is thinner and less cross-linked than the standard one. The water permeance in PERVAP™ 4100HF (∼800 GPU) is four-time higher than that in PERVAP™ 4100 (200 GPU) at 70 °C and for <5 wt.% of water concentration in the feed. The water/ethanol selectivity of the new membrane under this operating condition is very high (∼7000). The effect of feed water concentration on the Arrhenius activation energy was also investigated to evaluate the mass transfer through the membrane under other operating conditions, like higher temperatures and lower feed water concentrations. Simulation results confirmed that optimizing the operating temperature, the new membrane exhibits outstanding separation performance for drying ethanol below 500 ppm of water. Lastly, the ethanol drying process using the PERVAP™ membranes is compared with a molecular sieve system. Although the new membrane can easily dry ethanol below 500 ppm of water, a hybrid system consisting of pervaporation followed by molecular sieves leads to an interesting process solution, e.g., for a feed flow of 1000 kg/h, the required membrane area and the quantity of molecular sieves can be reduced from 650 m2 to 250 m2 (2.6 times less), and from 2252 kg to 204 kg (11 times less), respectively. Therefore, the ethanol drying process can be greatly optimized in terms of capital costs and energy when using a hybrid system instead of using pervaporation or molecular sieve system alone.

Melamine‐Crosslinked Polyimide Aerogels from Supercritical Ethanol Drying with Improved In‐Use Shape Stability Against Shrinking

Polyamide Aerogels In article number 2100645 by Fenglei Zhou and co-workers, thanks to the in-advance introduction of supercritical ethanol drying, the in-use shape stability of melamine-crosslinked polyimide (MPI) aerogels is greatly improved. It shrinks by only 2.64 vol.% after being treated at 280 °C for 72 h. The aerogels also show enhanced compressive strength, low thermal conductivity, excellent thermal stability and char forming ability, promising for high-temperature applications in thermal insulation.

Characterisation of Curcumin-loaded Egg Albumin Powder

Curcumin was encapsulated using egg albumin as a carrier material by desolvation and spray drying methods. Curcumin-loaded egg albumin powder was analysed for its in vitro release pattern, structural changes, morphology, stability, and antioxidant capacity. In vitro release studies showed that the cumulative release of 5.32, 47.76, 50.58, and 60.63% from pure curcumin from the powders prepared using ethanol, acetone, and spray drying, respectively, in 72 h. The FT-NIR spectrum of curcumin-loaded egg albumin powder confirmed that the curcumin and egg albumin maintained their chemical structure during drying process. FESEM images revealed that particles were in spherical shape and in the size ranges of 50 nm to 400 nm and 50 nm to 350 nm for nanoparticles prepared using ethanol and acetone, respectively. SEM images of spray dried particles showed that the particle size ranged from 1 μm to 15 μm without any agglomeration. Curcumin retentions of 74.66, 75.93, and 70.64% were observed in powder prepared using ethanol, acetone, and spray drying, respectively, after 50 min of heating at 100 ºC. Thus, the encapsulated samples were thermally stable, and could be used in food preparations as natural yellow colourant as functional food ingredient. Total antioxidant capacity of curcumin-loaded egg albumin powder prepared using ethanol, acetone, and spray drying was 5.96±0.89, 4.58±0.23, and 6.97±0.44 μg of ascorbic acid equivalents, respectively, at 100 μg.ml-1 sample concentration. Curcumin retained within the formulations was found to be stable without any change in the physical appearance throughout the storage period.

Melamine‐Crosslinked Polyimide Aerogels from Supercritical Ethanol Drying with Improved In‐Use Shape Stability Against Shrinking

AbstractPolyimide aerogels are promising for diverse applications owing to their nano‐porous structure and superior properties. However, the shrinkage of melamine‐crosslinked polyimide (MPI) aerogels has greatly compromised their performance in practical applications. In this study, supercritical drying with ethanol rather than CO2 is employed to enhance their in‐use shape stability at high temperatures. The structure, thermal insulation, mechanical strength of the resultant aerogels as well as their shape stability are characterized. Experimental results reveal that the shape stability of MPI aerogels during use is greatly improved thanks to the in‐advance baptism of supercritical ethanol drying. The aerogel shrinks by only 2.64 vol.% after being treated at 280 °C for 72 h. Besides, the MPI aerogel shows enhanced compressive strength and can easily support a load more than 20 000 times its own weight. The thermal conductivity of these aerogels varies from 0.034 to 0.046 W m−1 k−1, indicative of remarkable performance in thermal insulation. In addition, the aerogels that started to decompose at as high as 500 °C also perform well in thermal stability and char forming. It can be envisaged that the developed MPI aerogels with greatly improved in‐use shape stability may have broad prospects for thermal insulation at high temperatures.

Impacts of Ethanol Production and Drying Conditions on the Chemical, Physical, and Flowability Properties of Distillers Dried Grains With Solubles.

The production of corn-based ethanol in the U.S. has dramatically increasied in recent years, and consequently so has the quantity of coproduct feed ingredients generated from this segment of the grain processing industry. These streams are almost exclusively utilized as livestock feed, which partially offsets the need for corn in feed rations, but other value-added applications do exist. Because of its use as an animal feed, considerable research has been conducted into the nutritional properties, but to a lesser extent the physical and flowability properties of commercially-produced distillers dried grains with solubles (DDGS). There can be occasions when the quality of coproducts is not consistent. Thus questions regarding the influence of processing operations on the resulting coproduct characteristics must be examined. The objective of this research was to conduct extensive physical and flowability property analyses on DDGS samples which were produced under varying conditions in a pilot plant-scale ethanol plant, in order to investigate the effects of various manufacturing operations (specifically ethanol production and drying conditions) on the resulting properties of the DDGS. Using various laboratory methods, a variety of properties, including bulk density and angle of repose, were determined. DDGS fat content was highly correlated with aerated and packed bulk densities, which indicates that fat level plays a key role in flowability behavior. Future studies should examine this potential relationship in more depth, especially as the industry has moved to fat reduction via oil separation processes.

Ethanol Dry Reforming over Mn-Doped Co/CeO2 Catalysts with Enhanced Activity and Stability

This work mainly focused on the promotional effect of the Mn dopant on the catalytic behavior of the Co/CeO2 catalyst by selecting ethanol dry reforming as the model reaction. Herein, the as-prepared catalysts (CoCe and CoCeMn) were characterized by Brunauer–Emmett–Teller, X-ray diffraction, hydrogen temperature programmed reduction, X-ray photoelectron spectroscopy, Raman spectroscopy, and transmission electron microscopy to depict the influence of the Mn promoter on the physicochemical features. The results indicated that the presence of Mn species in the CoCeMn catalyst could improve the structural properties such as increasing the specific surface area, strengthening the active metal–support interaction, enhancing catalyst reducibility, and generating more oxygen vacancies. Generally, it was accepted that these positive factors could improve the catalytic performance. Therefore, the catalytic activity/stability of the CoCeMn catalyst was much better than that of the undoped CoCe sample. In addition, the possible mechanism of the catalyst antisintering/anticoking was also proposed to further elucidate the important role of the dopant Mn.

Effect of Drying Methods on Properties of Potato Flour and Noodles Made with Potato Flour.

This work investigated the impact of three drying methods on structural and functional properties of potato flour (PF), as well as the quality characteristics of fresh noodles made from wheat-potato flours. The results indicated that ethanol drying (ED) and oven drying (OD) had small effects on the properties of starch in potato flour, however, freeze drying (FD) caused some pores and channels on the starch granules and disruption of the long- and short-range ordered structure of starch. The maximum addition of potato flour in fresh noodles was 40% for FD-PF and 50% for both ED-PF and OD-PF. With increasing addition of potato flour in noodles, the L* (lightness) values of noodles decreased gradually, while the a* (redness) and the b* (yellowness) values, as well as the hardness and springiness values of fresh potato noodles increased. This study clearly showed that drying methods have different effects on the properties of potato flour, and in turn the quality of fresh noodles made with potato flour.

Effects of Alkali Metals on Nickel/Alumina Catalyzed Ethanol Dry Reforming

Although ethanol dry reforming is an attractive carbon utilization technology, problems of severe coke formation and low catalytic activity should be solved for realization of the technology. We demonstrate the effects of alkali metal additives (lithium, sodium, and potassium) on nickel catalyzed ethanol dry reforming. Potassium doped nickel catalyst (Ni/K2O-Al2O3) showed enhanced catalytic activity and durability in ethanol dry reforming. Thermogravimetric analysis (TGA) showed that Ni/K2O-Al2O3 had a high resistance to coke formation. The amounts of coke formed on Ni/K2O-Al2O3 were 1/3 lower than the amounts of coke formed on Ni/Al2O3. The total coke quantities were closely correlated to the number of basic sites of the nickel catalysts. Raman spectroscopy and transmission electron microscopy analyses revealed that the alkali metals control the coke formation on the catalysts.

MOF-Derived CoCeO &lt;sub&gt;x&lt;/sub&gt; Nanocomposite Catalyst with Enhanced Anti-Coking Property for Ethanol Dry Reforming

MOF-Derived CoCeO &lt;sub&gt;x&lt;/sub&gt; Nanocomposite Catalyst with Enhanced Anti-Coking Property for Ethanol Dry Reforming

Cellulose aerogel particles: control of particle and textural properties in jet cutting process

Reported approach aims for the synthesis of spherical cellulose beads with high production rates (0.7–4.1 kg/h of hydrogel) via the so-called jet cutting method. To form particles, jets of aqueous cellulose/sodium hydroxide solutions were cut into pieces and collected in a gelation bath (30 wt% aqueous H2SO4, 20 °C). After solvent exchange with ethanol and subsequent supercritical drying, cellulose aerogel particles were obtained. The particles showed high specific surface areas (ca. 400 m2/g) and low bulk (untapped) densities (0.06–0.10 g/cm3). Variation of cellulose content (4–7 wt%) and jet cutting process parameters (cutting frequency, nozzle diameter, jet velocity) turned to be useful parameters for controlling the particles size and shape. Highly spherical particles with sphericity SPH ≥ 0.92 were obtained in a broad range of achievable particle sizes (0.4–1.0 mm), with an optimum of SPH at 6 wt% cellulose content.