Browsing by Subject "wettability"

Now showing 1 - 11 of 11

Access status: Open Access ,
An effect of aromatic diluent addition on the selected properties of epoxy resin
(2005) Hutera, Barbara; Drożyński, Dariusz
The article describes the studies which have been conducted on the dynamic wetting of quartz grains by EPIDIAN 5 resin and by this resin with an addition of 5 wt. %, 20 wt. % and 30 wt. % of xylene at different temperatures. In the case of the investigated resin, the wetting process dynamics is best described by a logarithmic function: theta = A Int + B0, where: theta is the contact angle after time t, and A and B0 are constants characteristic of this process at a given temperature. It has been proved that with 5 wt. % addition of xylene both constants assume a value different than zero. With addition of 20 wt. % and 30 wt. % of xylene, the State of equilibrium is reached almost immediately, and it is expressed by a zero value of constant A. The infrared spectroscopy did not reveal the presence of any chemical reactions between the EPIDIAN 5 resin and xylene, thus confirming that the chemical structure of xylene molecule affects the type of interaction and proves the non-active behaviour of xylene as a diluent. The importance of the studies for foundry sand practice has been stressed.
Access status: Open Access ,
Jak termodynamika i mechanika opisują makroskopową oraz molekularną istotę zwilżalności
(2007) Grodzka, Janina; Pomianowski, Andrzej Aleksander
Recent studies on wetting lead to the two most important conclusions: description (estimation) of wettability needs the knowledge of not only the macroscopic wetting angle but also of the nature of molecular aqueous films that occupy surfaces of all solids; mechanical equilibrium of the wetting process is generally much more rapidly established than the thermodynamic equilibrium of the whole system. In consequence, the macroscopically measured wetting angle is different from the equilibrium angle, when the thermodynamic equilibrium and the formation of the molecular water film on the solid are not attained. Rapidly proceeding investigations of molecular wettability, carried out with the use of AFM (atomic force microscopy), will lead in the near future to unification of the theory and practice of wetting, and in particular will solve the question of the hysteresis of wetting, resulting from changes in the structure of water, directly adjacent to the surfaces of solids.
Access status: Open Access ,
New concept of hardware and software setup for wettability and surface tension analyzing system
(Wydawnictwa AGH, 2011) Sankowski, Dominik; Albrecht, Andrzej; Wojciechowski, Rafał; Bąkała, Marcin
Zjawiska na granicy fazy stałej i ciekłej odgrywają znaczącą rolę w wielu procesach w metalurgii, w obszarach inżynierii materiałowej i powierzchniowej, dotyczy to technologii lutowania, produkcji materiałów kompozytowych, spiekania proszków itp. Pełna analiza zjawisk międzyfazowych wymaga znajomości parametrów napięcia powierzchniowego i kąta zwilżania. W artykule przedstawiono koncepcję konfiguracji sprzętowo-programowej dla systemu analizatora zwilżalności i napięcia powierzchniowego - dedykowanego rozwiązania pozwalającego na projektowanie, przeprowadzanie i analizę eksperymentów pozwalających na ilościowe określenie ww. parametrów. Zostały opisane i omówione szczegóły projektowe, m.in. struktura systemu, interakcje, jak również metodologia eksperymentów pomiarowych.
Access status: Open Access ,
Selection of protective coatings obtained by plasma-spraying method for foundry industry
(2017) Richert, Maria Wiesława; Nejman, Ilona; Zawadzka, Paulina; Kacprzyńska-Gołacka, Joanna
This article presents results from the studies of protective coatings applied to industrial graphite molds used for the casting of non-ferrous metals. The selection of coatings was based on the results of measurements of surface wettability by liquid copper and microstructure examinations. The study involved industrial graphite molds with single-layer protective coatings of Al₂O₃ + 30%C and ZrO₂-Y₂O₃ + 30%C as well as two-layer protective coatings of Al₂O₃ + 30%C /glassy carbon and ZrO₂-Y₂O₃ + 30%C /glassy carbon.
Access status: Open Access ,
Substantiation of fluid saturation of reservoir-rocks on the basis of petrophysical studies
(2008) Fedišin, Volodimir; Nesterenko, Mikola
The method of quantitative estimation of porous medium structural parameters by distinctive areas of capillary pressure curves is proposed, according to which the part of hypercapillary, capillary and subcapillary pores is being determined. Their relations stipulate to a great extent the character of reservoir rocks saturation with residual water and hydrocarbon fluids. Differentiation of oil is carried out in reservoir rocks (Horizon V-22 of Buhru-vate and horizons V-20-21, V-25-26 of Yuliyivs'k fields of Dniepro-Donets depression), in Lower Cretaceous terrigenous and Upper Jurassic carbonate reservoirs of Lopushnia field (Precarpathian oil and gas bearing region) and in reservoir rocks of Middle Cambrian Age of Girkaliai field (Baltic oil bearing region) by parameters of its displacement taking into account hydrodynamic and capillary forces. That permitted to advance arguments for total and recoverable oil reserves of the above-mentioned fields.
Access status: Open Access ,
The influence of physical and chemical parameters of modified water glass on the strength of loose self-setting sands with water glass
(2012) Kmita, Angelika; Hutera, Barbara
An attempt of water glass modifying by 30% water bochmite Al(OH)O solution was undertaken. The flow curves were determined and the binder viscosity estimated from them. The quartz wettability by binders was determined by measuring the wetting angle θ changes with time. Strength properties of moulding sands with fractions of modified binders were verified by checking the tensile strength R$_m^u$ after various hardening times under environmental conditions. The R$_m^u$ value after 24 h of hardening was assumed for the analysis.
Access status: Open Access ,
The influence of wettability on oil recovery
(2015) Kulinič, Vitalij
Understanding the mechanism by which oil is displaced from the porous medium requires knowledge about the role of wetting and capillary forces during EOR. Knowledge of the effect of wettability on oil production is also a key point for understanding the behavior of multiphase flows in the reservoir. A literature review indicates that wettability is one of the main factors controlling and regulating the distribution of oil and water in the reservoir rock. Therefore, the resolution of problems associated with the calculation of oil resources, operation and analysis of core deposits, must take into account the wettability of rock. Therefore, the study of such phenomena as wettability is still valid today. In the paper reservoir rock wettability and its types were described. Direct and indirect methods of determining the wettability were characterized, the graph of capillary pressure is used to characterize the wettability. In order to determine the effect of wettability on multiphase flow in porous media are discussed petrophysical parameters: capillary pressure, relative permeability and hydrocarbon saturation of the rock. Characterized wettability of each of the porous medium of carbonate and sandstone reservoirs.
Access status: Open Access ,
The influence of wettability on the petrophysical parameters of reservoir rocks
(Wydawnictwa AGH, 2017) Kulinič, Vitalij
Knowledge of the reservoir rock wettability and its influence on petrophysical properties is a key factor to determine the mechanisms and assess the efficiency of oil recovery. In the reservoir rock at the presence of different liquids, it is very important to obtain information about the type of wettability of the rock. Since the understanding of the relationship between wettability and distribution of water and oil in the pore space is necessary to assess the efficiency of oil recovery. Wettability is one of the main parameters that determines the position of the liquid in the reservoir pore space and fluid flow. Wettability affects the properties of petrophysical rock containing hydrocarbons, among others, saturation, capillary pressure, relative permeability, electrical properties of reservoir rocks. Also affects the multiphase flow in porous media. The aim of this article is to characterize the petrophysical parameters of rocks dependent wettability, an overview of the research state of the impact of wettability on the selected petrophysical parameters and presents directions of the future research.
Access status: Open Access ,
Thermoresponsive nanofiber yarns for water harvesting enhanced by harp system
(2024) Parisi, Gregory; Szewczyk, Piotr K.; Narayan, Shankar; Stachewicz, Urszula
WIMiIP
The escalating global water crisis necessitates innovative approaches to developing sustainable water resources. Fog water collectors with variable surface wettability offer controlled fog harvesting in water-scarce regions. This study develops thermoresponsive fog collecting materials by electrospinning poly(N-isopropylacrylamide)-polyvinylidene fluoride (PNIPAm-PVDF) into yarns that are transformed into harp-like structures for enhanced water harvesting rate. Both meshes and harps using electrospun membranes exhibit the remarkable ability to transition between hydrophilic and hydrophobic wetting states at temperatures below the lower critical solution temperature (LCST). Hydrophilic and hydrophobic surfaces play distinct roles in fog water collection. Hydrophilic surfaces have a high affinity for water and enables droplet capture. Hydrophobic surfaces help the removal of aggregated water droplet and fog water collection. The highest water collection rate obtained with the electrospun PNIPAm-PVDF harp was 1415 ± 7.0 mg·cm−2 h−1. The water harvesting system based on the electrospun PNIPAm-PVDF harps exhibits a 485 % increase in water collection compared to the standard meshes made from the same material, emphasizing their potential for significantly improving the overall rate in fog water harvesting applications.
Access status: Open Access ,
Wettability gradient of photoresponsive electrospun yarns for harp-based fog water harvesting
(2024) Parisi, Gregory; Szewczyk, Piotr K.; Narayan, Shankar; Stachewicz, Urszula
WIMiIP
Fog water harvesting offers a solution to water scarcity. Here, we introduce a method to enhance fog water harvesting systems utilizing electrospun yarns featuring a wettability gradient. These yarns, made from polyvinylidene fluoride (PVDF) and titanium dioxide (TiO2), gain photoinduced hydrophilicity under UV light due to TiO2 photocatalytic properties, allowing dynamic shifts from hydrophobic to hydrophilic states. Experiments show that an alternating PVDF-TiO2 harp with a wettability gradient surpasses purely hydrophobic or hydrophilic versions in fog collection. The strategic mix of hydrophobic and hydrophilic sections enhances droplet movement and water capture, achieving a 16% increase in collection rate up to 400 mg cm−2 h−1. This approach introduces a novel method for creating wettability gradients in electrospun yarns via UV irradiation and represents a significant advancement in adaptable fog water harvesting systems.
Access status: Restricted ,
Wstępna ocena bioaktywności i zwilżalności nanokompozytów poliacetalowych zawierających modyfikowany powierzchniowo hydroksyapatyt
(Data obrony: 2017-01-25) Karaś, Ewelina
Wydział Elektrotechniki, Automatyki, Informatyki i Inżynierii Biomedycznej