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Effect of bio-oil on low-intermediate temperature properties of organosolv lignin-bitumen
Published in Xianhua Chen, Jun Yang, Markus Oeser, Haopeng Wang, Functional Pavements, 2020
Y. Zhang, X. Liu, S. Ren, R. Jing, W. Gard, P. Apostolidis, S. Erkens, A. Skarpas
The virgin binder which was used in this research was a 70/100 pen grade bitumen of 47.5°C softening point. The pure lignin was a kind of nutbrown powder provided by the Chemical Point UG (Germany). Lignin particles with purity over 87% are extracted by organosolv methods. Helium Pycnometer Test was used to accurately measure the density of lignin was 1.3774 g/cm³. The surface measuring system (Dynamic Vapor Sorption) was used to calculate the specific surface area of lignin by Braunauer-Emmett-Teller (BET) method was 147.0593 m²/g. The physical parameters of lignin were tested after aging as well. The apparent color of lignin particles became darker, the density was increased to 1.5029 g/cm³ and the specific surface area was decreased to 65.0475 m²/g (Zhang et al., 2020). Lignin particles became more compact with a smaller specific surface area after aging. The bio-oil used in this study was one of the most common rapeseed oil with saturated, monounsaturated, and polyunsaturated fatty acids.
Preliminary study on using lignin as aging inhibitor in bitumen
Published in A. Kumar, A.T. Papagiannakis, A. Bhasin, D. Little, Advances in Materials and Pavement Performance Prediction II, 2020
Y. Zhang, X. Liu, R. Jing, P. Apostolidis, S. Erkens, A. Scarpas
The specific surface area was calculated by Braunauer-Emmett-Teller (BET) method after conducting surface measurements in a Dynamic Vapor Sorption (DVS) device. The amount of lignin was about 50 mg necessary due to the high uptakes of vapors on the high surface area. The ambient temperature 25°C was selected, and a 100-sccm flow rate was used in the test. The typical partial pressure range for BET experiments was 0.05 to 0.30% (P/P0). It was therefore ideal to collect an isotherm between these limits using 5% P/P0 steps. The BET method assumed a physical adsorption mechanism in monolayer coverage was obtained, followed by multilayer adsorption, it could be applied to any adsorption system. The total surface area and the specific surface area were determined.
Guidance on Formulating Compressed Solids
Published in Sarfaraz K. Niazi, Handbook of Pharmaceutical Manufacturing Formulations, Third Edition, 2019
Micronization, where possible, allows increase in the surface area to the maximum, which can impact on the solubility, dissolution, and as a result, bioavailability. Since the aim of most preformulation studies is to determine if a solid dosage form can be administered, knowing that reduction of particle size, where it changes dissolution rates, can be pivotal in decision making for the selection of dosage forms. In the process of micronization, the drug substance is fed into a confined circular chamber, where it is suspended in a high-velocity stream of air. Interparticulate collisions result in a size reduction. Smaller particles are removed from the chamber by the escaping air stream toward the center of the mill, where they are discharged and collected. Larger particles recirculate until their particle size is reduced. Micronized particles are typically less than 10 μm in diameter. In some instances, micronization can prove counterproductive, where it results in increased aggregation (leading to reduced surface area) or alteration of crystallinity, which must be studied using such methods as microcalorimetry, dynamic vapor sorption (DVS), or inverse gas chromatography (IGC).
Poly(aspartic acid) superabsorbent polymers as biobased and biodegradable additives for self-sealing of cementitious mortar
Published in Journal of Sustainable Cement-Based Materials, 2023
Lauren De Grave, José Roberto Tenório Filho, Didier Snoeck, Sofiya Vynnytska, Nele De Belie, Katrien V. Bernaerts, Sandra Van Vlierberghe
Dynamic vapor sorption (DVS) measurements were carried out to determine the moisture uptake capacity of the material at different relative humidities (RH) and the hysteresis of the sample upon desorption. The DVS device consists of a Cahn microbalance, a temperature-controlled housing and mass flow controllers to control the flow of wet and dry N2 gas. This set-up allows to control both RH and temperature. For these measurements, the temperature was set at 20 °C. 10 mg freeze-dried SAP powder was placed in the sample pan. A first step of RH 0% was established to start with completely dry material. Afterwards, the RH was increased in systematic steps of 10%, with a final step of 8%, until a RH of 98% was reached. Every subsequent step was initiated when the change in sample mass as a function of time was lower than 0.002 mg min−1. After an equilibrium value was obtained at the highest RH, desorption was realized by decreasing the RH in the same systematic steps as the sorption process until full desorption was realized.
Experimental investigation on air dehumidification performance of metal organic frameworks and its application potential for solid desiccant air conditioning systems
Published in Science and Technology for the Built Environment, 2023
Jinzhe Nie, Yuxin Pang, Jilei Liu, Xiangrui Kong, Han Zhang
From the literatures, MIL-101(Cr) has shown prominent physical properties and adsorption performance for moisture. However, the dehumidification performance of MOFs under building ventilation and air conditioning cases hasn’t been deeply investigated. In this paper, MIL-101(Cr) and its modified material MIL-101(Cr)-SO3H having strengthened structural stability are selected as investigated MOFs. Experiment measurements were conducted to explore their moisture adsorption/desorption performances with air as carrier gas and under solid desiccant air conditioning thermal cases. For details, following the meteorologic design parameters of air conditioning and ventilation systems in Beijing, several thermal conditions were set as the experiment cases. The experiment measuring methods include:Vacuum Vapor Sorption (VVS) method was firstly used to measure the moisture adsorption capacity of investigated desiccants under pure moisture environment.Dynamic Vapor Sorption (DVS) method was used to explore the moisture adsorption/desorption isotherms and adsorption velocities of investigated desiccants under moist air environment.Dynamic Vapor Sorption (DVS) method was used to explore the moisture desorption rate and low-temperature regeneration ability of the materials.
The moisture migration behavior of wheat starch/gluten blended powders and extrudates
Published in Drying Technology, 2021
Gong Yanfei, Yingquan Zhang, Bo Zhang, Guo Boli, Wei Yimin
Moisture sorption isotherm (MSI) has been used to describe the relationship between the equilibrium moisture content and water activity (aw) at constant temperature.[1] The gravimetric and dynamic vapor sorption methods are traditional and recognized methods to assess the water sorption isotherm. The vapor sorption analyzer (VSA) is a new type of automatic isotherm generator that can generate isotherms using the dynamic vapor sorption (DVS) and dynamic dew point isotherm (DDI) methods (Aqulab VSA operator manual). VSA has been demonstrated to be an accurate instrument for generation of the equilibrium sorption isotherms for food materials.[2] MSIs are useful thermodynamic tools for the determination of the interactions between water and food materials to provide information that can be used for selection of appropriate storage conditions and packaging systems that optimize the retention of aroma, texture, nutrients and biological stability. Furthermore, water-binding energy, which can be calculated from the MSIs, has been used to describe the combination state between water and a solid matrix and is useful for the prediction of drying models and in the design of drying equipment.[3]