Fast Absorption Rate Research Articles

Industrial alkali lignin-derived biochar as highly efficient and low-cost adsorption material for Pb(II) from aquatic environment

Developing a cost-effective and high-efficiency biochar is critical in various environmental applications. Lignin-based materials are natural and abundant adsorbents to heavy metals benefited from their special polyphenol structure and physicochemical properties. In this study, adsorption capacities to Pb(II) by alkali lignin (AL) and its biochar derivative (ALB) were comparatively discussed, and the latter exhibited superior adsorption performance, with a maximum adsorption capacity almost twice that of the former, and a much faster absorption rate. The qm value of ALB was significantly superior to that of other reported biochar materials. Pb(II) was mainly adsorbed into ALB in three forms: mineral precipitation, ion exchange, and surface complexation, with complexation and mineral precipitation being the dominant mechanisms of adsorption. This study demonstrates that alkali-lignin derived biochar is a promising material for the remediation of polluted by Pb(II).

One-step fabrication of chitosan sponge and its potential for rapid hemostasis in deep trauma

In this paper, a facile and efficient preparation strategy for a porous and hydrophilic chitosan sponge is demonstrated, combining a surfactant and a pore-foaming agent. The resulting chitosan sponge possesses an interconnected pore structure and soft texture, exhibits fast water absorption rate and capacity, and the compressed sponge can achieve full shape recovery 5 s after absorbing water. Moreover, our process removes the residual acid commonly found in chitosan sponges prepared by the acid method. In addition, the results demonstrate the useful characteristics of our chitosan sponge, in terms of its contribution to improved blood coagulation, together with its compression strength and biocompatibility. It also demonstrates effective antibacterial properties in relation to both Escherichia coli and Staphylococcus aureus. Further testing via animal experimentation reveals that rapid hemostasis can be achieved within 50 s using our chitosan sponge.

A high-protein/high-energy fruit dessert is as effective as milk-based oral nutritional supplement to increase blood leucinemia in older women.

Rationale: Sarcopenia contributes to frailty and loss of autonomy and results from a decreased anabolic action of meals due to a loss of skeletal muscle sensitivity to dietary amino acids in elderly. Several strategies are based on optimizing the quantity and quality of protein intake. Whey with fast digestion and absorption rates has proven to be very effective, but such proteins properties are considerably reduced when these ones are added to a complex food matrix. The REMUS project aims at developing a novel matrix containing a rapid and vectorized milk protein to potentiate the bioavailability of amino acids in the elderly regardless product texture.

In Vitro and In Vivo Evaluation of Oral Disintegrating Nanofiber and Thin-Film Contains Hyperbranched Chitosan/Donepezil for Active Drug Delivery

Hyperbranched chitosan (HPCN) has been synthesized from the polycondensation route and transformed into an oral thin film (HCTF) and nanofiber (HCNF) formulation with the addition of donepezil drug. Chitosan blended hyperbranched polyester (HBPE) prepared and formulated as a nanofiber (CNHPN) and thin film (CNHPF). Both carried out to process for the treatment of Alzheimer’s disease. Higher thermal stability and porous surface with fiber diameter (110 to 115 nm) observed for hyperbranched nanofiber formulations. Faster disintegration (15 s) of nanofiber (HCNF 2) achieved in vitro drug release about 97.03% of drugs with an interval of 45 min. In vivo animal model studies demonstrated that plasma absorbing maximum concentration (Cmax ) as 18.94 ng/mL for CNHPN 2 formulation at the lowest time-bound (3.3 h). The total are under curve [AUC(0–∞)] of hyperbranched chitosan has faster absorption rate (978.1 ng/mL) than marketed formulation (132.05 ng/mL). These results suggested that chitosan blended/hyperbranched chitosan nanofiber formulation is good alternative with commercial formulations for the treatment of Alzheimer’s disease.

CO2 absorption rate in biphasic solvent of aminoethylethanolamine and diethylethanolamine

Amine scrubbing is currently the most promising technology for CO2 capture from gas turbine and coal-fired flue gas. It is hindered by high regeneration energy and high capital cost. Biphasic solvent of 25% aminoethylethanolamine (AEEA)/50% diethylethanolamine (DEEA) could be a potential solution as it may achieve significant reduction in regeneration energy. A fast CO2 absorption rate is preferred to reduce the capital cost of the absorber. In this work, the CO2 absorption rate (kg′) of the biphasic solvent was measured in a wetted wall column at 40 °C and at the loading conditions in the absorber. At CO2 equilibrium partial pressure (PCO2*) lower than 100 Pa, 25% AEEA/50% DEEA is homogeneous. The CO2 absorption rate, kg′, is as fast as 30% PZ (3 times faster than 30% MEA). When PCO2* is greater than 100 Pa, 25% AEEA/50% DEEA forms aqueous and organic phases after CO2 absorption. It was first found that the organic phase of 25% AEEA/50% DEEA absorbs CO2 2–7 times faster than the aqueous phase because of greater physical CO2 solubility at the same PCO2* and physical mass transfer coefficient. The kg′ of the organic phase is much faster than 30% MEA and 25% AEEA at lean and rich loading and even greater than 30% PZ at lean loading. The instantaneous reaction mechanism fits the kinetics of CO2 absorption in the organic phase at low PCO2*. The slow kg′ of the aqueous phase results from greater viscosity which significantly reduces the physical mass transfer coefficient. The CO2 capacity of the aqueous phase is 2.9 times, 1.8 times, and 5.3 times greater than that of 30% MEA, 30% PZ, and the organic phase, respectively.

Absorption of sulphur dioxide by electrosprayed droplets

AbstractThis paper describes and discusses experimental results on the absorption of sulphur dioxide in electrified water sprays, either when the polluted gas is treated as is or when the gas is exposed to a corona source to ionize the sulphur dioxide. The experiments revealed that an electrified spray with a charge‐to‐mass ratio of 50 μC · kg−1 enabled the absorption rate of droplets to double, regardless of their polarities. Corona charging gave rise to an increase in the SO2 depletion rate over the scrubber wall, while negligible effects appeared on the actual droplets absorption rate. These findings suggested that faster absorption rates mostly, though not uniquely, depend on the modifications on the morphological and interfacial properties of the sprayed droplets induced by the free electric charge imposed on their surface. Conversely, the absorption rates were negligibly affected by the electrical interactions between droplets (either charged or uncharged) and the sulphur dioxide ions/radicals originating from the corona source.

Super hygroscopic nanofibrous membrane-based moisture pump for solar-driven indoor dehumidification

Desiccants play vital roles in dehumidification and atmospheric water harvesting; however, current desiccants have mediocre hygroscopicity, limited recyclability, and high energy consumption. Herein, we report a wood-inspired moisture pump based on electrospun nanofibrous membrane for solar-driven continuous indoor dehumidification. The developed moisture pump with multilayer wood-like cellular networks and interconnected open channels is composed of a desiccant layer and a photothermal layer. The desiccant layer exhibits an unprecedented moisture absorption capacity of 3.01 g g−1 at 90% relative humidity (RH), fast moisture absorption and transport rates, enabling atmospheric water harvesting. The photothermal layer shows a high solar absorption of 93%, efficient solar thermal conversion, and good moisture permeability, thus promoting water evaporation. The moisture pump efficiently reduces the indoor relative humidity to a comfort level (40‒60% RH) under one-sun illumination. This work opens the way to develop new-generation, high-performance nanofibrous membrane-based desiccants for energy-efficient humidity control and atmospheric water harvesting.

Anti-evaporation Performance of Water in Soil of Superabsorbent Resin with Fast Water Absorption Rate

Hydroxypropyl cellulose-g-poly (acrylicacid-co-2-acrylamido-2-methyl-1-propane sulfonic acid)/laterite (HPC-g-P (AA-co-AMPS)/laterite) with excellent water (salt) absorbency, water retention performance, re-swelling property, and fast water absorption rate was prepared by free-radical polymerization. The structure and morphology of the synthetic materials were characterized by FTIR, SEM, and TGA. The water absorbency of superabsorbent resin in different salt solutions was studied, and it was proved that the superabsorbent resin was more sensitive to salt solutions. The swelling kinetic mechanism of superabsorbent resin was explained by pseudo-second-order swelling kinetic model. The effects of the ratio of laterite to loess on water evaporation and the content of superabsorbent resin on soil water evaporation and shrinkage of soil crust were studied.

Protic ionic liquid‐based deep eutectic solvents with multiple hydrogen bonding sites for efficient absorption of NH3

AbstractThe emerging of ionic liquids (ILs) provides an efficient and sustainable way to separate and recover NH3 due to their unique properties. However, the solid or highly viscous ILs are not suitable for traditional scrubbing. Therefore, an effective strategy was proposed by combining the protic ILs (PILs) with acidic H and low viscous ethylene glycol (EG) to form IL‐based deep eutectic solvents (DESs) for NH3 absorption. The results indicated that these PIL‐based DESs not only have fast absorption rate, but also exhibit exceptional NH3 capacity and excellent recyclability. The highest mass capacity of 211 mg NH3/g DES was achieved by [Im][NO3]/EG with molar ratio of 1:3, and was higher than all the reported ILs and IL‐based DESs, which was originated from multiple hydrogen bonding between acidic H and hydroxyl groups of the DESs and NH3. This work will provide useful idea for designing IL‐based solvents for NH3 separation applications.

Enrichment of heat transfer in a latent heat storage unit using longitudinal fins

AbstractThe charging and discharging rates of a phase change material (PCM) in a horizontal latent heat storage unit (LHSU) is largely influenced by the lower thermal conductivity of the PCM. In the present research, four different configurations of longitudinal fins are proposed to augment the heat transfer in horizontal shell and tube type LHSUs. Numerical investigations are reported to establish the thermal performance augmentation with rectangular, triangular, and Y‐shaped (bifurcated) fins. From the results, it has been inferred that all fin configurations provide a faster charging and discharging rate. In the present set of geometric dimensions of LHSU considered, a reduction in charging time of 68.71% is evaluated for case III (three rectangular fins with one fin positioned in the area of the heat transfer fluid [HTF] surface) and case V (two bifurcated fins with one fin positioned in the area of the HTF surface). Moreover, overall cycle (charging + discharging) time is reduced by 58.3% for case III. Employment of fins results in a faster rate of absorption and extraction of energy from the PCM.

Study on CO2 capture by AAILs-MDEA aqueous solution in packed tower

This study mainly uses N-methyldiethanolamine (MDEA) as the main body of absorption, and uses three kinds of AAILs(AAILs), 1-butyl-3-methylimidazolium lysinate ([Bmim][Lys]), tetramethylammonium glycinate ([N1111][Gly]) and 1-butyl-3-methylimidazolium glycinate ([Bmim][Gly]) as accelerator, respectively. That forms a new blended aqueous solution for CO2 removal. The new AAILs-MDEA aqueous solution absorbent has stronger ability to absorb CO2, faster absorption rate and lower equipment corrosion. When the gas flow rate is 500ml/min and the liquid flow rate is 150ml/min, the best removal efficiency is achieved. At 313.2K, the removal efficiency of MDEA-[N1111] [Gly] absorbent can reach 100%; the effect of the three new alkanolamine aqueous solutions on CO2 absorption is: MDEA-[N1111][Gly]>MDEA-[Bmim] [Gly]>MDEA-[Bmim][Lys].

Properties of aqueous amine based protic ionic liquids and its application for CO2 quick capture

Three kind of pure amines which have high solubility of CO2 were used as absorbents hardly to be recovered. A series of aqueous ethoxyacetate anion-based protic ionic liquids (PILs) with three different amine cations were designed, and physical properties including measured density and viscosity were measured. Solubility of CO2 in the three PILs solution, 90% [DMAPAH][EOAc], 90% [DEEDAH][EOAc] and 90% [DMEDAH][EOAc], were systematic determined at the range of 303.2–333.2 K under the pressure of 1.2 bar. Impressively, the solubility of CO2 in 90% [DMAPAH][EOAc] reached up to 2.44 mol/kg, which showed more advantage than some traditional or functional ILs. The 90% [DMAPAH][EOAc] could be reused four times. Besides, the proposed mechanism was advised. Considering the advantages of high absorption capacity, low cost, easy regeneration including fast absorption rate, we believe the three PILs solution can be recommended as alternatives to some volatile organic amines to be applied in CO2 capture.

CO2 Absorption from Gas Turbine Flue Gas by Aqueous Piperazine with Intercooling

Amine scrubbing is the most mature technology for postcombustion carbon capture. Much bench- and pilot-scale work has been focused on CO2 capture from coal-fired flue gas. Because natural gas is inexpensive and readily available in the United States and other countries, the natural gas combined-cycle (NGCC) has been replacing coal for electricity generation. Carbon capture for NGCC is therefore an important technology for the modern power plants. The Piperazine (PZ) Advanced Stripper (PZAS) technology has been established as a benchmark system for second-generation amine scrubbing for CO2 capture from coal-fired flue gas. It has a fast absorption rate, good energy performance, and strong resistance to thermal degradation and oxidation. PZAS was operated with simulated NGCC flue gas (4.3 mol % (dry) CO2) at the National Carbon Capture Center (NCCC) in Wilsonville, Alabama in 2019. This paper presents the absorber performance and model validation for the campaign. The absorber was tested with in-and-out and with pump-around intercooling. The variable operating conditions included lean loading (0.19–0.25 m CO2/mol alkalinity), gas temperature (40, 78 °C), and intercooling temperature (35, 40 °C). Using 5 m PZ CO2 removal from 82% to 96% was achieved with intercooling and only 12 m of packing. A rigorous, rate-based absorber model accurately predicted the CO2 removal and temperature profile. The model shows that the delta loading of the solvent at NGCC conditions for 90% removal is greater than at coal conditions, but high CO2 removal (99%) is more difficult to achieve with NGCC gas than with coal-fired flue gas. The pump-around intercooling was effective, and the intercooling temperature had a large impact on the absorber performance. With pump-around, the delta loading penalty for hot gas feed into absorber without a direct contact cooler was less than 5%.

Preparation of superabsorbent resin with fast water absorption rate based on hydroxymethyl cellulose sodium and its application

To study the application of superabsorbent resin (SAR) in preventing water evaporation in soil, hydroxymethyl cellulose sodium-g-poly (acrylic acid-co-2- acrylamido-2-methyl-1-propanesulfonic acid)/laterite (NaHMC-g-P (AA-co-AMPS)/ laterite) was prepared by radical polymerization. The structure and morphology of SAR were characterized by FTIR, SEM and TGA. The factors affecting the water absorbency of SAR were studied and the water absorption of the resin under the optimum synthetic conditions reached the equilibrium at 15 min in distilled water, and the optimum water absorption of SAR was 1329 g/g, 269 g/g and 140 g/g in distilled water, tap water and 0.9 wt% NaCl solution, respectively. The swelling kinetic mechanism of the SAR was explained by the pseudo-second-order swelling kinetics model and Ritger-Peppas model. The effects of soil type, particle size and content of SAR on water evaporation rate in soil were studied.

Postcombustion Capture of CO2 by Diamines Containing One Primary and One Tertiary Amino Group: Reaction Rate and Mechanism

Developing ideal amine solvents with a high CO2 absorption capacity and a fast absorption rate is an attractive avenue to advance the amine scrubbing technology. In this regard, diamines bearing one primary and one tertiary amino group (1°/3° diamines) are proposed to be promising solvents for CO2 absorption, which can exhibit the fast CO2 absorption rate of primary amines while maintaining the diamines’ intrinsic high absorption capacity. Here, we present a detailed kinetic study of four 1°/3° diamines for CO2 absorption and investigate the relationship between the structure of various 1°/3° diamines and their CO2 absorption rate. Results showed that increasing alkyl spacer between two amino groups within 1°/3° diamines promoted the CO2 absorption rate, while a large decrease in their reactivity with CO2 was observed when the tertiary amino group existed in the cyclic structure. Among these studied 1°/3° diamines, 3-(dimethylamino)-1-propylamine (DMAPA) displayed the highest absorption rate under relevan...

Application of empirical Peleg model to study the water adsorption and mineral desorption of cocoa (Theobroma cacao) beans in water and sodium bicarbonate during debittering process

The ability of water and sodium bicarbonate solution in producing debittering cocoa bean for immediate consumption as ready to cook food and the applicability of empirical Peleg model in order to interpret the sorption data is evaluated in this study. Fermented cocoa beans were soaked and/or boiled in water and in 2% sodium bicarbonate solution with a weight to volume ratio of 1:10. Cocoa beans were withdrawn at each interval over a 6-h time period and moisture and minerals (calcium, magnesium, phosphorus and potassium) content analyzed using standard analytical methods. Bitterness was measured by sensory analysis. Peleg model was used to transform the sorption data into the mathematical equation and Peleg parameters K1, K2 and Me calculated. It has been found that boiling in water and sodium bicarbonate (2%) significantly reduces the bitterness of cocoa beans. Kinetic curves of water absorption express the characteristic shape with a fast water absorption rate at the beginning of the process follow by a decreasing rate as the equilibrium moisture is reached. Mineral desorption curves exhibited unusual pattern depending on the mineral under consideration. Application of sorption data demonstrates a predictive capacity of the Peleg model as judged by the regression coefficients. Boiling cocoa beans for 50min in 2% sodium bicarbonate and 30min in boiling water can be considered as optimal for debittering cocoa beans in order to give them palatable option to be integrated in nutrition and in none medicinal therapeutics in Cameroon.

EcoFlex Sponge with Ultrahigh Oil Absorption Capacity.

A paraffin microsphere-templated 3D porous EcoFlex sponge was prepared to selectively absorb oil or chemicals from water. The technology for producing this EcoFlex sponge does not need complicated synthesis processes or instruments, and the materials applied in this work are ecofriendly. Therefore, this sponge can be employed in the environmental field. EcoFlex sponges showed high hydrophobicity (contact angle = 140-143°) and oleophilicity. The developed sponge exhibits a porous three-dimensional framework inside with excellent internal connectivity, which contributes both better absorption capacity and faster absorption rate. For instance, the absorption capacity for chloroform can reach3400 wt %. Theabsorption capacity of the sponge was optimized using different size of paraffin microspheres and these sponges exhibit relatively high absorption capacity in a short time (2 min). The volume of sponge expands in some oils and organic solvents: the increased volume capacity for hexane can reach 2200%. This sponge also has great recovery capability and durability; it keeps its original shape and absorption capacity after 15 cycles of oil absorption and compression.

Pharmacokinetic and pharmacodynamic modeling of gut hormone peptide YY(3–36) after pulmonary delivery

Peptide YY(3–36) (PYY(3–36)) is an endogenous appetite suppressing peptide. The present research was to perform pharmacokinetic/pharmacodynamic (PK/PD) analysis for predicting the concentration- and response-time profiles of PYY(3–36) after systemic and pulmonary delivery in mice, with the goal of suggesting a potential pulmonary dosing regimen in humans. A PK/PD model was developed to describe PYY(3–36) plasma concentration - and relative food intake rate ratio (as % of control) - time profiles after intraperitoneal and subcutaneous administration, and inhalation in mice. The absorption of inhaled PYY(3–36) from the lungs of mice could only be described with a combined slow (absorption rate of 0.147 L/h) and fast (absorption rate of 104.4 L/h) absorption process, presumably related to absorption from the central and peripheral regions of the lungs. The estimates for IC50 and Imax were 6.8 ng/mL and 63.5%, respectively, based on inhibitory Emax model. The PK parameters, such as clearance (CL), volume of distribution at steady state (Vdss), and the absorption rates (ka), were then scaled to human’s. The scaled human CL and Vdss for obese subjects were 24.8 L/h and 9.0 L, respectively. The model predicted human plasma PYY(3–36) concentrations agreed reasonably well with placebo-normalized plasma PYY(3–36) concentrations after short-term infusion and SC injection in literature. An inhalation dose of PYY(3–36) of about 100 µg was proposed for obese subjects based on simulations. This PK/PD analysis satisfactorily described PYY(3–36) concentration-time and relative food intake rate ratio- time profiles at all doses and routes. The developed model might facilitate the inhalation dose selection of PYY(3–36).

Significantly improving strength and oil-adsorption performance of regular porous polydimethylsiloxane via soft template approach

A soft template, polyethylene glycol (PEG), was used for the preparation of polydimethylsiloxane (PDMS) oil absorbent. The preparation can be finished does not involve special equipment that normally required by conventional duplicating processes base on hard template. PEG/PDMS ratio, the key synthesis parameter, was systematically optimized in terms of both oil capacity and mechanical strength. Compared with previously reported PDMS materials developed using hard template, the optimized absorbents have comparable capacities of various oils in the range of 4.5–21.5 g/g, faster absorption rate and significantly improved mechanical strength with elongation at break significantly enhanced from 60 to 97% to greater than 200%. These improved properties can be explained by the regular distribution of macropore size that exhibits a signature twin-head peak dominated at about 120 and 200 μm. That fractional distribution is not affected by increased PEG/PDMS ratio until a structural collapse occurs at the ratio of 6 suggests specific and uniform interactions between PEG soft template and PDMS. Also examined are recyclability, anti-deformation property and oil-keeping performance, which are of practical importance under realistic storage and application conditions were also examined.

Synthesis and characteristics of fire extinguishing gel with high water absorption for coal mines

Coal mine fires pose a threat to the lives of underground workers and cause incalculable losses to the national economy. When a fire occurs, the temperature in the underground wells will rise, which becomes a huge hidden danger that needs to be controlled to prevent disasters. In this paper, using sodium carboxymethyl cellulose as a matrix and through graft copolymerization of acrylic acid and 2-acrylamide-2-methylpropanesulfonic acid, a novel fire-extinguishing gel with high water absorption and high resistance has been prepared. It has a high water absorption ratio as well as an excellent fire prevention effect. The microscopic reaction and structure of the product are analyzed by infrared spectroscopy, thermogravimetry, X-ray diffraction and scanning electron microscopy. By testing the properties of the gel, it is proven that the product has a fast water absorption rate with a high ratio, strong salt tolerance, good water retention and the obvious effects of filling, sealing and fire extinguishing.