Wet Particle Size Research Articles

Experimental Investigation of Particle Size Degradation and Plugging Efficiency of Three Granular Lost Circulation Materials

This work delineates a comprehensive study of one of the main problems that contributes towards nonproductive time (NPT) in a drilling operation, which is lost circulation. The focus of this study was to investigate the performance of walnut, graphite, and marble, which are three widely used and industry-available granular lost circulation materials (LCMs). Additionally, the study aimed to establish a particle size selection guideline for better operational performance and plugging efficiency. Four water-based carrier fluid systems (water–bentonite mix, water–polymer mix, and two polymer–salt systems) were tested with the LCMs in this study. Dry and wet particle size degradation studies were conducted on all the LCMs with the different carrier fluid systems to study their compatibility and efficiency. The effect of the carrier fluid type was proven to be significant only on marble particles size degradation; walnut and graphite were not affected by the carrier fluids and showed consistent size degradation performance with all fluids. The results of this work led to newly developed particle size selection guidelines to enhance plugging efficiency—guidelines that are custom-made for each material by taking into consideration the rate of the degradation and type of material and by correlating the findings with fracture width. Applying this method of investigation to the current lost circulation management practice can help resolve many lost circulation incidents by effectively and efficiently selecting the appropriate LCM.

Hydrophobic modification of kaolinite by coating with the conductive polythiophene and investigation of the usability as the environmental-based sensors

To prepare an electrically conductive clay-composite, in this work, the surface of kaolinite plates was covered with the hydrophobic polythiophene (PTh) nanoparticles, through in-situ oxidative polymerization of thiophene in an organic solvent mixture. By changing the polymerization conditions such as types of solvents used as polymerization media, volume ratios of the solvents in the mixture, and mole ratios of the oxidant/monomer, the composite with the highest conductivity (7.95 × 10–5 S cm−1) was obtained. Depending on the polythiophene (PTh) content (%) of the composite, Vickers microhardness, elastic modulus, Brunauer, Emmett, and Teller (BET) analysis, wet particle size distribution, and water contact angle measurements were performed. It was observed that the hydrophilic nature of kaolinite remarkably altered after the incorporation of PTh particles. FTIR, XRD, TGA, and SEM–EDX techniques were also used for the characterization of the composite. The performance of the composite in the environmental-based sensors, including humidity and temperature sensing, were examined, and the resistance values of the composite exhibited quite stable and reproducible responses, especially to the temperature changes, between 1 and 120 °C compared to the pure PTh.

Tensile and thermal properties of nanocellulose-reinforced poly(vinyl alcohol) nanocomposites

This work reports on the mechanical and thermal properties of poly(vinyl alcohol) (PVA) nanocomposites reinforced with nanocelluloses isolated by the sulfuric acid hydrolysis using commercial microcrystalline cellulose (MCC). Nanocellulose-reinforced PVA nanocomposite films were prepared by the casting method with different nanocellulose loadings, which were exposed to tensile test, thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA). The nanocellulose obtained by the acid hydrolysis was a rod-like whisker form. Wet particle size analysis resulted in an average size of about 340 nm. But, the measurements of individual nanocelluloses using transmission electron microscopy (TEM) provided the dimensions of about 6.96 nm wide and 178 nm long. The crystallinity of the nanocellulose was quite high (85.2%), which was greater than that of the MCC. The tensile modulus and strength of the nanocomposites were improved with an increase in the nanocellulose content, but decreased at the nanocellulose content of 7 wt%. Thermal stability of the nanocomposites was improved as the nanocellulose content increased up to 7 wt%. The DMA result shows a significant increase of the storage modulus of the nanocomposite at the 3 wt% nanocellulose. These results indicate that the nanocellulose has a great potential to reinforce PVA polymers.

Sorption and desorption of Cd, Cr, Cu, Ni, Pb and Zn by a Fibric Histosol and its organo-mineral fraction

It has often been stated that the contribution of soil organic matter (OM) to the sorption of heavy metals can be evaluated using the surface horizon of a Histosol as typical of soil organic matter. However, components of Histosols other than organic matter, such as clay minerals and Fe or Mn oxides, can also sorb heavy metals. In this work we compared the heavy metal sorption and desorption behaviour of a Fibric Histosol H horizon with that of its organo-mineral fraction (OMF, defined as the fraction of wet particle size <100 μm) in experiments in which Cd, Cr, Cu, Ni, Pb and Zn were sorbed simultaneously from solutions of various concentrations. The OMF sorbed the metals reversibly and apparently mainly at specific sites to each particular metal, in keeping with the good fit of Langmuir isotherms to the sorption data; greatest sorption capacity was for lead and copper. Whole H horizon appeared to include sites at which binding was less reversible and chromium competed with the other metals, especially copper. Organo-mineral fraction is suggested to evaluate the soil organic matter contribution to heavy metal fixation.

In situ comparative measurements of the properties of aerosol droplets of different chemical composition

Aerosol optical tweezers can be used to manipulate multiple aerosol particles simultaneously. When coupled with spontaneous and stimulated Raman scattering, the composition, size and phase partitioning of different chemical components within a liquid droplet can be investigated. In combination, these two techniques suggest the possibility of a new strategy for characterising the thermodynamic behaviour of aerosols and the kinetics of mass transfer between the gas and condensed phases. We demonstrate here that two droplets can be characterised simultaneously, examining specifically the variation in wet particle size with relative humidity, recording the changes in size with nanometre accuracy. In a further demonstration, we use the size of a sodium chloride droplet to determine the relative humidity of the gas phase, allowing the variation in hygroscopicity of a second aqueous glutaric acid/sodium chloride droplet to be studied. We suggest that such a comparative approach can provide new insights into aerosol dynamics.

Manipulation and Characterization of Aqueous Sodium Dodecyl Sulfate/Sodium Chloride Aerosol Particles

Aerosol optical tweezers coupled with Raman spectroscopy can allow the detailed investigation of aerosol dynamics. We describe here measurements of the evolving size, composition, and phase of single aqueous aerosol droplets containing the surfactant sodium dodecyl sulfate and the inorganic salt sodium chloride. Not only can the evolving wet particle size be probed with nanometer accuracy, but we show that the transition to a metastable microgel particle can be followed, demonstrating that optical tweezers can be used to manipulate both spherical and non-spherical aerosol particles. Further, through the simultaneous manipulation and characterization of two aerosol droplets of different composition in two parallel optical traps, the phase behavior of a surfactant-doped particle and a surfactant-free droplet can be compared directly in situ. We also illustrate that the manipulation of two microgel particles can allow studies of the coagulation and interaction of two solid particles. Finally, we demonstrate that such parallel measurements can permit highly accurate comparative measurements of the evolving wet particle size of a surfactant-doped droplet with a surfactant-free droplet.

Malvern Instruments: new Insitec LPS provides complete solution for continuous wet particle size measurement

Malvern Instruments: new Insitec LPS provides complete solution for continuous wet particle size measurement

Characterization of the swelling of a size-exclusion gel.

The swelling of a dextran gel, Sephadex G-75, was observed in an aqueous environment at room temperature by a noninvasive technique that uses light microscopy coupled to an image analysis system via a video camera. The rate of swelling was found to follow the Tanaka and Fillmore theory, from which the overall gel diffusion coefficient was estimated as 6.3 x 10(-7) cm2/s. In addition to giving a quantitative measure of gel swelling that could be useful in the mechanical design of liquid chromatography columns, this approach provides data on wet particle size and particle size range, which is needed for the modeling of diffusional and mass transfer effects in size-exclusion chromatography. In this context, key observations are that the gel particles are nearly spherical with an elliptical shape factor of 0.98 (perfect sphere = 1) and that there is little difference between sizes of particles obtained in water, 50 mM Tris-glycine buffer (pH 10.2), and buffer containing 1 mg/mL protein. The diameter of the dry material ranged from 20 to 100 microns, while the hydrated particles had diameters of 40-350 microns. The rate of swelling is rapid, with 50% swelling occurring in about 10 s and swelling to 99% of the final wet particle size being obtained in less than 90 s.

On the effect of the chemical composition of atmospheric aerosol particles on nucleation scavenging and the formation of a cloud interstitial aerosol

Nucleation scavenging and the formation of a cloud interstitial aerosol (CIA) were theoretically studied in terms of the chemical composition of atmospheric aerosol particles. For this study, we used our air-parcel cloud model, which includes the entrainment of air and detailed microphysics, for determining the growth and interaction of aerosol particles and drops. Maritime and remote continental aerosol particle spectrums were used whose size distributions were superpositions of three log-normal distributions, each of a prescribed chemical composition. Our results show (1) that the CIA exhibits a size distribution with a distinctive cut-off at a specific radius of the dry as well as of the wet particle size distribution. All particles above this limiting size become activated to cloud drops and, thus, are not present in the CIA spectrum. This limiting size was found to be independent of the chemical composition of the particles and only dependent on the prevailing supersaturation. Below this specific size, the CIA spectrum becomes depleted of dry aerosol particles in a manner which does depend on their chemical composition and on the supersaturation in the air. (2) The number of aerosol particles nucleated to cloud drops depends critically on the chemical composition of the particles and on the prevailing supersaturation.