Pycnometer Method Research Articles

Density, thermal expansion, dynamic viscosity of halogenated arenes

Purpose. Experimental study of the density, thermal expansion and dynamic viscosity of halogenated arenes at temperatures from 293.15 to 343.15 K and atmospheric pressure 97.992 kPa.Methods. Density was determined by the pycnometric method, viscosity by the capillary method. A quartz pycnometer type PZh2 with a nominal capacity of 10 ml and a glass capillary viscometer type VPZh-2 with a nominal capillary diameter of 0.34 mm were used. The mass of liquids was measured using an electronic scale VSL-200/0.1A with a division value of 0.0001 g. Numerical methods were used to process the experimental results.Results. Experimental data were obtained on the density, coefficient of volumetric thermal expansion and dynamic viscosity of liquid o-xylene, ethylbenzene, fluorobenzene, chlorobenzene, bromobenzene, toluene, o-fluorotoluene, mfluorotoluene, p-fluorotoluene, o-chlorotoluene, m-chlorotoluene, p-chlorotoluene, 2,4-dichlorotoluene, 2,6-dichlorotoluene. Density and dynamic viscosity data are approximated by a third-degree polynomial. Data on the coefficient of volumetric thermal expansion are obtained from approximated measured density data. The maximum estimate of the measurement error for density was 0.13 %, for dynamic viscosity – 3.5 %. The maximum calculation error for the coefficient of thermal expansion is estimated at 3 %.Conclusion. Mathematical processing of the obtained experimental data on density and dynamic viscosity made it possible to obtain analytical relations in the form of power polynomials that allow calculating the values of these quantities at any temperature from the studied temperature range and atmospheric pressure with an error not exceeding the error of experimental determination. The calculated values are in good agreement with the data provided in the reference and scientific literature. The experimental data obtained complement the information on the properties of some of the liquids under consideration, for which the dependences of density and viscosity on temperature are poorly understood. The substances under study are used in various sectors of the economy and are therefore technically important liquids. The measurement results can be used in condensed matter physics, for the analysis of liquid hydrocarbons, and can be useful in the chemical industry.

Density and stability of oil-in-water emulsions

The stability of oil-in-water emulsions is determined by the physicochemical properties of oil, as well as the composition of emulsified water. The present work aims to study the effect of concentration and temperature on the density and stability of oil-in-water emulsions. Classical oil emulsions of the first type were prepared with aqueous CaCl2 solution and oil from the Yarakta field. The ratios of the hydrocarbon component to the aqueous phase were as follows, vol %: 5:92, 10:87, 15:82, 20:77, 25:72, 30:67, and 35:62 with the addition of emulsifier. The density of emulsions was studied using the pycnometer method, with a measurement error of up to ±0.01 kg/m3. The method consists in accurately determining the mass of the test solution and distilled water, which occupy a known volume (50 cm3) in the pycnometer, and using a high-precision analytical scale. The obtained regression equations provide a means to calculate the densities of oil-in-water emulsions within the studied temperature (20–60 °С) and oil concentration (5–35 vol %) ranges. The derived empirical equations can be used in practice. It is shown that with increasing oil concentration and temperature, the density of emulsions decreases. The stabilizing ability of oil-in-water emulsions was evaluated in terms of luminous transmittance: the luminous transmittance value served as a stability criterion of emulsions in water. It was experimentally confirmed that the stabilizing ability of emulsions decreases with increasing temperature. The obtained results can be used in the study of regularities defining the direction and extent of chemical transformations and stabilization of oil-in-water emulsions, as well as in the solution of practical issues related to their destruction.

High entropy (HfTiZrVNb)B2 ceramic particulate reinforced Al matrix composites: Synthesis, mechanical, microstructural and thermal characterization

This study aims to introduce a novel type of particulate reinforced Al matrix composite. High entropy (HfTiZrVNb)B2 ceramic particulate reinforced Al matrix composites were produced via a combined process of different powder metallurgy methods. Firstly, boride compounds (HfB2, TiB2, ZrB2, VB2, NbB2) were synthesized in the laboratory scale using the related metal oxide, boron oxide, and magnesium by mechanochemical synthesis (MCS) and leaching processes under optimum conditions. Secondly, the synthesized and purified boride powders were mixed in equimolar ratios using a planetary ball mill for 72 h, and they were sintered at 2000 °C under 30 MPa via spark plasma sintering (SPS). Thirdly, equimolar high entropy (HfTiZrVNb)B2 bulks were crushed, converted into powder forms, and added into Al powders at different amounts as 1, 2, 5, 10, and 15 wt %. Lastly, these powder blends were mechanically alloyed in a vibratory ball mill for 6 h, cold pressed and pressureless sintered at 630 °C for 2 h. For characterization techniques, X-ray diffractometry (XRD), thermal analysis, scanning electron microscopy/energy dispersive spectrometry (SEM/EDS), density measurements using pycnometer and Archimedes' methods, microhardness and dry sliding wear tests were conducted on the sintered composites. The highest hardness (∼1.5 GPa) and the lowest wear rate (∼0.0012 mm3/Nm) were obtained in the Al-15 wt % (HfTiZrVNb)B2 sample.

Determination of the porosity characteristics by pycnometric methods

Data on pore size distribution in solids are obtained by pycnometric density-based methods for measuring the pore structure of materials. The results of measuring open porosity by weighing a dry sample followed by evacuation and saturation with distilled water at atmospheric pressure, impregnation with water under pressure using a hydrostat and mercury porosimetry are presented. The samples of porous nickel obtained using powder technology by sintering of the compacts from mixtures of nickel nanopowder with powder ammonium bicarbonate NH4HCO3 (a blowing agent), the volume fractions of which were 80 and 20%, respectively, were studied. A powder blowing agent with a particle size of 63 – 125, 140 – 200, and 250 – 315 μm was used. A theoretical estimation of the pore size available for the penetration of the impregnating liquid was carried out for three methods used for the determination of open porosity. It is shown that upon water saturation after evacuation the liquid can penetrate only into pores larger than 3 μm. Moreover, in porous structures with a large fraction of submicron pores, the actual values of the open porosity are significantly underestimated when using the method of saturation with distilled water after evacuation. The higher the fraction of fine pores in the material, the lower the open porosity value. The difference between the open porosity values determined by methods of water impregnation using a hydrostat and mercury porosimetry was negligible. It has been established that among three considered methods for measuring open porosity, only the method of saturation with distilled water after evacuation cannot be used in analysis of structures with submicron pores. The results obtained can be used to develop porous functional materials and products with a given porosity structure.

PSII-24 Relationship Among Color, Physicochemical Traits, and Ruminal in Situ Dry Matter Digestion of Corn Grains from Argentina, Brazil, and the United States

Abstract Corn-derived starch and rumen-degradable protein (RDP) available for rumen microbial fermentation vary significantly with corn hybrid and environmental conditions. Identifying corn physicochemical traits potentially correlated with ruminal DM digestibility would facilitate the prediction of its nutritional value compared with more time-consuming determinations. We assessed 1) the effect of corn origin on color, physicochemical traits, and 22-h in situ DM digestibility (22h-DMD), and 2) the relationship of color and physicochemical traits with 22h-DMD on Argentinian (AR, n = 29), Brazilian (BR, n = 4), and North American (US, n = 15) corn samples. The hardness-associated properties measured were: color (Hue angle; H) and physicochemical traits [crude protein (CP), thousand kernel weight (TKW), test weight (TW, Schopper chondrometer with ¼ L capacity), floaters (FLO, percent of kernels floating in a sodium nitrate solution), kernel density (KD, pycnometer method), vitreousness (VIT), and coarse-to-fine milling ratio (C:F)]. In situ 22h-DMD was determined using two ruminally cannulated steers receiving a 53:47 forage-to-concentrate ratio diet. Mastication was simulated by grinding a 100-g sample for 10 s using a 0.625-cm screen. For each steer, three sets of 4-g (DM basis) of each corn sample were placed into R1020 Ankom bags and introduced in the ventral sac of the rumen at two independent events separated by 48 h. Four bags per sample were placed in a water bath (39 °C, 15 min) to determine the soluble fraction (0h-DMD). Corn origin effect on color and physicochemical traits and on 0h-DMD and 22h-DMD were tested using GLM and MIXED procedures, respectively. Means were compared by Tukey-Kramer test. Relationships among variables were studied using a correlation matrix (PROC CORR) and stepwise multiple linear regression (PROC REG). All traits differed (P < 0.01; Table 1) among corn origin, being AR corns intermediate in hardness-associated properties between BR and US samples, though more similar to BR ones. Correlation coefficients (P < 0.01) of 22h-DMD with H, FLO, TW, KD, C:F, and CP, were 0.43, 0.80, −0.77, −0.71, −0.82, and −0.72, respectively; TKW was unrelated (P = 0.26) to 22h-DMD. The predictive 22h-DMD equation (P < 0.01) based on physicochemical traits was 22h-DMD (%) = 160.31 – 1.16 × TW (kg/hL) – 7.49 × C:F (g/g; RMSE = 3.54, R2 = 0.74). Softer kernels with higher H and FLO and lower TW, KD, C:F, and CP, demonstrated greater 22h-DMD than harder samples. Indeed, TW and C:F resulted in reliable predictors of 22h-DMD to describe the nutritional value of corn samples. Succinctly, AR and BR corn hardness-associated properties contrasted with US ones. We hypothesized that greater CP and reduced 0h-DMD and 22h-DMD of harder genotypes may reduce or eliminate the need for RDP supplementation when those grains are included in beef cattle finishing rations; however, more research is warranted on this topic.

Exploring the mechanism of solubilization and release of isoliquiritigenin in deep eutectic solvents

Isoliquiritigenin (ISL) is a natural medicinal product with extensive pharmacological activities. However, its low solubility limits its application. Therefore, this study aimed to explore the solubilization and release mechanism of the ISL using deep eutectic solvents (DESs). The choline chloride (ChCl) and oxalic acid (OA)/malic acid (MA)/gallic acid (GA) were used to synthesize ChCl-OA/MA/GA DESs, and the solubility of ISL in these DESs was studied to explore the solubilization mechanism of ISL. The thermodynamic properties of DESs were characterized using differential scanning calorimetry (DSC). The molecular interactions in DESs were studied using spectroscopy and molecular dynamics (MD) simulations. The relative density of DESs was measured using a pycnometric method, its accuracy was validated by comparing it with the MD simulation. The release of ISL from ChCl-OA/MA/GA eutectogels was studied using Carbomer 940 as the thickener, and the release mechanism of ISL in the eutectogels was explored by the drug release kinetic model. The solubility study found that the solubility of ISL in ChCl-OA/MA/GA DESs is 30073, 5055, and 68,103 times higher than that in an aqueous solution. In addition, further studies using MD simulations revealed that enhancing the interactions between ISL and solvent molecules can improve the solubility of ISL in DESs. In vitro release studies showed that the release of ISL in ChCl-OA/MA/GA eutectogels followed a first-order release model, with correlation coefficients of 0.9812, 0.9916, and 0.9961, respectively. In conclusion, the study of the solubilization and release mechanism of ISL in DESs provides new ideas and methods for the study of poorly soluble drugs, which is expected to improve the efficacy and clinical application value of drugs.

MAGNETIC-CONTROLLED SORBENT FOR WATER SURFACE CLEANING FROM OIL POLLUTION

The modern structure of industry, outdated technologies form a wide range of environmental problems and sharply worsen the ecological situation. Various methods are used to clean water sources from oil spills: mechanical, thermal, physicochemical, biological. Among the available alternatives, oil sorbents are considered as one the most economical, efficient and environmentally friendly materials because oils can be properly absorbed by oil sorbents without causing secondary water pollution.
 The purpose of the research is to study the possibility of obtaining an effective magnetically controlled sorption material for cleaning the water surface from oil spills.
 Research objectives are to analyze the composition of electric arc steel-smelting furnaces (EASSF) dust; conduct research on the hydrophobization EASSF dust with paraffin; determine the optimal proportions of dust and hydrophobizator, which allow the material to maintain buoyancy and magnetic susceptibility; evaluate the interaction of the obtained material with an oil spills on water surface.
 The dust sample elemental composition was obtained using the ARL9900 Intellipower Workstation.
 The sorption material was prepared as follows: the EASSF dust was mixed with a sample of paraffin, then it was heated to 105 °C in an oven, mixed, and cooled to a temperature of 20 °C.
 The true density was determined by the pycnometric method. The method ASTM D2854-70 «Standard Test Method for Apparent Density of Activated Carbons» was used to determine the bulk density.
 Electric steelmaking waste was used as a magnetically susceptible component. Studies have been carried out on its hydrophobization with paraffin for possible use in water treatment. With the waste : paraffin ratio of 1 : 0.07, a material with high hydrophobicity and buoyancy was obtained. Tests for thickening and extracting a crude oil spill from water surface proved the promise of using the obtained material for cleaning water from oil pollution.

A study of lunar soil simulants from construction and building materials perspective

Ten lunar soil simulants originated from North America and Europe were analysed in this paper. Properties important from civil engineering perspective (especially for future large-scale field experimental studies associated with lunar aggregate and lunar concrete-like composite) were of special interest. The tested properties included: bulk density in loose and vibrated state, density measured using the pycnometer method, particle size distribution, median particle size, coefficient of uniformity, coefficient of curvature, cohesion, inner friction angle and angle of repose. A microscopic analysis was also conducted. The properties of soil simulants were compared to average properties of lunar soil brought by Apollo and Luna missions. Finally the Principal Component Analysis was performed in order to select simulants most similar to the lunar soil.

Densities, Excess Volumes, and Partial Molar Volumes of Butyl Methacrylate Solutions in Some Organic Solvents

Densities and excess volumes of the binary systems of butyl methacrylate with acetonitrile; acetic acid, benzene, 1,2-dichlorethane, and hexane have been measured as a function of composition at 293 K and atmospheric pressure by pycnometric method. The measured excess volumes were correlated by polynomials. The partial molar volumes were calculated by experimental data.

Performance Evaluation of Polysachharide based Biomaterials for Sand Stabilization

Recent research on soil improvement have showed that the use of biopolymers can significantly enhance the various engineering properties of the soil. Soil improvement using biopolymers has attracted considerable attention in recent years, with the aim to reduce the harmful environmental effects of traditional materials. This report aims to provide a review on the environmental assessment of biopolymers as binders in soil improvement, biopolymer-treated with soil characteristics, as well as the most important factors affecting the behavior of the treated soil. Various geotechnical properties are evaluated and compared, including the unconfined compressive strength, and durability of biopolymer-treated soils. The usage of biopolymers has positive effects on the soil in the form of enhanced strength, However, a thorough understanding of the geotechnical qualities is required in order to completely apply the biopolymer technology to the fields. Biopolymer kinds, soil types, biopolymer contents, curing times, thermal treatment, and mixing techniques all play a significant role in how effective biopolymers are at improving the ground. In this part of study, the pycnometer method, sieve analysis, standard proctor compaction tests, unconfined compression test, durability, gel plug tests, pH test, and FTIR test, were used to understand and analyze the pectin-treated sand. Keywords: Pectin,Geotechnical Engineering,Bio Polymer- Treated soil

Prospects for the Development of Reference Materials of the Wobbe Index

The thermophysical properties of gaseous fuel, including the calorific value and the Wobbe index, are one of its main properties for industrial use. The correctness of measurements of the volumetric energy of gas combustion is currently ensured by using sets of certified reference materials of the lowest volumetric energy of combustion based on pure gases: hydrogen, methane, ethane and propane GSO 11662–2020 / GSO 11665–2020 and gaseous mixtures GSO 11904–2022 / GSO 11907–2022 with metrological traceability to GET 16–2018. However, it becomes necessary to measure the gas relative density to air with established traceability to GET 18–2014 when determining the Wobbe index.The purpose of this research is to improve the accuracy of the pycnometer method for measuring the density of gases for further development and creation of metrological assurance in the field of measuring the Wobbe index.In the course of the research, an analysis of existing methods for determining the gas density was performed, as a result of which the pycnometer method set forth in GOST 17310–2002, GOST 34721–2021 was taken as the basis for the developed method. The uncertainty budget of gas density measurements was estimated using the pycnometer method. It has been established that the mass determination of the gas under study makes the greatest contribution to the total uncertainty. It was decided to increase the internal volume of the pycnometer and use a modified method for determining its volume to minimize the uncertainty.An imitator of a pycnometer with an increased volume was manufactured in an original design to solve the task of developing a modified pycnometer method for measuring the gas density. A gravimetrically produced gaseous mixture of the following composition was chosen for testing the developed method: CO2 – 40.22 mol. %, CH4 – rest.The theoretical significance of the results obtained lies in approbation of a modified pycnometer method to improve the measurement accuracy of such a gaseous fuel property as the Wobbe index. In the process of developing a modified pycnometer method, the measurement algorithm was tested, the density values of the studied gas were obtained, and the uncertainty budget of density measurements was estimated.The practical significance of the results of this research will expand the possibility of establishing metrological characteristics during the metrological assurance of Wobbe index analyzers, as well as apply the developed method in future accuracy control of the measurement results of the gas relative density to air.

Evaluation of Hold-Up Volume Determination Methods and Markers in Hydrophilic Interaction Liquid Chromatography.

Common methods for hold-up time and volume determination in Reversed-Phase Liquid Chromatography (RPLC) have been tested for Hydrophilic Interaction Liquid Chromatography (HILIC). A zwitterionic ZIC-HILIC column has been used for the testing. The pycnometric determination method, based on differences in column weight when filled with water or organic solvent, provides the overall volume of solvent inside the column. This includes the volume of eluent semi-sorbed on the packing of the column, which acts as the main stationary phase. The homologous series approach, based on the retention behavior of homologues in relation to their molecular volume, allows the determination of accurate hold-up volumes. However, the application of this method is time-consuming. In some cases, large neutral markers with poor dipolarity/polarizability and hydrogen bonding interactions can be used as hold-up volume markers. This is the case of dodecylbenzene and nonadecane-2-one in clearly HILIC behaving chromatographic systems, the use of decanophenone as a marker can be even extended to the boundary between HILIC and RPLC. The elution volume of the marker remains nearly unaffected by the concentration of ammonium acetate in the mobile phase up to 20 mM. The injection of pure solvents to produce minor base-line disturbance as hold-up markers is strongly discouraged, since solvent peaks are complex to interpret and depend on the ionic strength of the eluent.

X-ray computed tomography vs Archimedes method: a head-to-head comparison

Metal additive manufacturing (AM) is growing rapidly towards industrial adoption in various industries, but porosity remains a concern because it creates areas of stress that affects the mechanical properties and reduces reliability. Porosity can be quantified by X-ray computed tomography (XCT), but the method is relatively slow and expensive. The Archimedes density measurement method is widely used due to the low cost and ease of operation; however, it is limited in its precision for low porosity levels. In this work, a series of additively manufactured aluminium 6061-Ti6 alloy samples with different types and quantities of porosities are subjected to Archimedes, gas pycnometer and X-ray methods. This work clarifies the application range and limitations of each of these methods, using 10 mm cubes of Al 6061-Ti6 manufactured by laser powder bed fusion.

The Phenomenon of Biodiesel Heating: Its Effect on Viscosity, Density, and Emission

Biodiesel fuel is a mixture of diesel oil mixed with vegetable oil (palm). The composition of the mixture affects its properties, especially viscosity and density. The research was conducted to determine the effect of increasing temperature on these properties. By applying several experimental methods, including the ASTM D 445-95 method, the pycnometer method, and the particulate emission test method. The biodiesel test was carried out with variations in temperature of 30 o C, 40 o C, 50 o C, 60 o C, and 70 o C at room conditions of 24.0 o C temperature and 71% humidity. From the temperature variation, the viscosity is 2.23 cSt, 2.61 cSt, 3.1 cSt, 3.7 cSt, and 4.45 cSt. The results of the research prove that the increase in biodiesel temperature affects decreasing viscosity and density which has an impact on reducing particulate emissions.

Application of Density Measurements for Discrimination and Evaluation of Chemical Composition of Different Types of Mechanically Separated Meat (MSM).

At present, the problem of identifying and controlling different types of Mechanically Separated Meat (MSM) is a very important practical issue in the meat industry. To address this challenge, the authors propose a new, analytical method for the discrimination and characterization of MSM that uses density measurements. The method proposed by the authors, in contrast to the analytical methods existing so far, is rapid, non-destructive, relatively simple and can be computerized. The density measurements of meat samples were conducted with a modified pycnometric method. Statistically significant (p<0.01) differences were found in the evaluated mean values of density for all investigated types of meat. Subsequently, the density measurements were correlated with the physicochemical properties of meat samples. A high correlation coefficient was found between the density of meat samples and the content of protein, sodium and fat. The authors have proven that density measurements allow for rapid discrimination of various types of MSM, and can also be effectively used to determine the chemical composition of MSM samples, e.g., the content of protein, fat and sodium.

In Situ Validation Methodology for Weighing Methods Used in Preparing of Standardized Sources for Radionuclide Metrology

High-accuracy source standards preparation in radionuclide metrology is based on a properly described and reliable weighing procedure able to achieve relative standard uncertainties below 0.1%. However, the results of uncertainty budget comparison CCRI(II)-S7 put in check the ability of the former pycnometer and substitution weighing methods to attain this goal. As a result, a question arises about the validation of mass measurements performed from the elimination weighing method when appropriate uncertainties are required. In order to address this problem, a comprehensive in situ validation methodology is proposed for the results of the pycnometer, substitution, elimination and modified elimination (MEM) methods. Mass comparisons are applied to evaluate the compatibility between weighing methods’ results. It is possible due to a developed weighing sequence, which allows for the performing of all methods by only one drop deposition in the range of mass from 10 mg to 200 mg. As a result, the high degree of compatibility between the MEM and elimination method for uncertainties below 0.1% has been achieved, as well as for higher uncertainties to pycnometer and substitution methods. Numerical simulations indicate that the validation results remain valid on improved technical implementations for these last two methods.

Desorption and thermophysical properties of feijoa pulp as affected by temperature and moisture content

ABSTRACT Feijoa has a high nutraceutical and agro-industrial potential, an attractive opportunity for Colombia to enter new markets with innovative products. However, there is little knowledge about its behavior and requirements for its proper industrial processing. The studies of thermophysical and sorption properties are fundamental for analyzing and optimizing the different unit operations, evaluation, and product quality control. This study aimed to determine and mathematically model the physical, thermal, and water desorption properties of feijoa pulp in the physiological ripening stage. The desorption isotherms were determined using the gravimetric method, based on saturated salts’ solutions to create atmospheres of controlled relative humidity (RH, %), in this case, at temperatures (T) of 8°C, 23°C, and 38°C and water activities (aw) between 0.07 and 0.98. From the isotherms model that best fits the experimental data, the isosteric heat of sorption (Qs ), differential entropy (ΔSdiff ), and Gibbs free energy (ΔG) were calculated. The density (ρ), thermal conductivity (k), and specific heat capacity (cp) properties were determined and modeled at different moisture contents (H: 75%, 80%, 85%, and 90%) in the temperature range (T) 20 to 80°C, using the pycnometer method, concentric cylinder method, and differential scanning spectrophotometry (DSC), respectively. The desorption isotherms of the feijoa pulp were type III with equilibrium moisture contents (Xe ) between 0.1246 and 5.5135 kg/kg (dry basis, d.b.), a monolayer moisture content of 0.2 kg/kg (d.b.); and spontaneity of the sorption phenomenon. Both cp and k depended more on H than on T; while ρ showed an equal relationship with both factors; these behaviors are characteristic of high humidity foods. The mathematical models obtained in this study are a valuable contribution for the food industry for an effective agro-industrialization, use, and added value of feijoa pulp through the design, control, and optimization of processes and equipment that involve the transfer of heat and matter.

Structural characteristics of cellulose esters with different degrees of substitution

In this article, structural characteristics of amorphous mono-, di-, and tri-substituted esters of cellulose have been studied. These esters were synthesized under homogenous conditions using anhydrides of various aliphatic acids. The specific gravity of the highly substituted samples was measured by a pycnometric method in the aqueous medium. To calculate the molar, Van der Waals, and free volumes, as well as the packing coefficient of amorphous esters, the method of additive contributions of partial volumes of atoms and atom groups in the volumes of polymers was used. Based on the molar volume, also values of specific gravity of cellulose esters were calculated. The coincidence of calculated and experimental characteristics was shown. In addition, the relationship between glass transition temperature and free volume was found for the esters of cellulose. The theoretical equations were derived, which provide predicting the structural characteristics of cellulose esters with different degrees of substitution.

Study of Structural Characteristics of Cellulose Esters with Different Degrees of Substitution

In this article, structural characteristics of amorphous mono-, di-, andtri-substituted esters of cellulose have been studied. These esters weresynthesized under homogenous conditions using anhydrides of variousaliphatic acids. The specific gravity of the highly substituted samples wasmeasured by a pycnometric method in the aqueous medium. To calculatethe molar, Van der Waals, and free volumes, as well as the packingcoefficient of amorphous esters the method of additive contributions ofpartial volumes of atoms and atom groups in the volumes of polymerswas used. Based on the molar volume, also specific gravity of celluloseesters was calculated. The coincidence of calculated and experimentalcharacteristics was shown. In addition, the relationship between glasstransition temperature and free volume was found for the esters. Thetheoretical equations were derived, which provide predicting the structuralcharacteristics of cellulose esters with different degrees of substitution.

Evaluation of the Penetration Behavior of Viscous Fluids into Porous Media in the Context of Volume Determination

Abstract The current study addresses the penetration of viscous fluids into compacted clay samples in the context of volume determination. The volume of compacted clay samples was measured with established methods (paraffin-coated clod method, pycnometer method) and uncoated immersion weighing (IW) with three different fluids (silicone oil, paraffin oil, and canola oil). The suitability of the methods was evaluated statistically. The amount of penetrated liquid into the sample was tracked over time and analyzed. Experimental data were fitted with a modified Washburn’s equation considering different pore sizes in the sample. The fitting yielded very good matches. IW was found to generate the most accurate (i.e., smallest error measurements) and reproducible results for volume determination among the established methods. Thereby, paraffin and silicone oil performed best for IW. The penetration of liquids into the sample was found to be negligibly small for those two liquids in the relevant time range for conducting an IW.