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1

Synergistic effect between starch and sulfuric acid the separation of galena from chalcopyrite

Huang Xingguo, Cao Qinbo, Zhang Haiyu, Zou Heng, Yan Yan, Liu Dianwen, Wang Menglai, Du Lingpan

Physicochemical Problems of Mineral Processing

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2025

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Vol. 61, iss. 4

art. no. 209128

EN

Galena (PbS) is still hard to separate from chalcopyrite (CuFeS2) in China, necessitating more effective depressants. This study investigated a combined depressant system using sulfuric acid (H2SO4) and starch to selectively depress PbS in a PbS−CuFeS2 mixture. Single-mineral flotation experiments identified the optimal parameters to depress PbS at pH 3, 6 min reaction time, an H2SO4 to starch ratio of 6:1, and 700 mg/dm3 of H2SO4. Under these conditions, PbS recovery has decreased to 9.2%, while CuFeS2 recovery reached 81.1%, Furthermore, the PbS recovery with this combined depressant was significantly lower than the recovery with 700 mg/dm3 of H2SO4 (83.2%) or 116.7 mg/dm3 of starch (32.1%). FTIR results also showed that starch molecules could physically adsorb onto the PbS surface. Furthermore, XPS and SEM-EDS analyses revealed that the interaction between H2SO4 and the PbS surface produced oxidative components, i.e., Pb-O and SO42−. These oxidative species may interact with the OH groups in starch molecules, enhancing the adsorption of starch molecules and thus efficiently producing a hydrophilic PbS surface. This study proposes an effective approach for the depression of PbS using the H2SO4 and starch combination. These combined reagents exhibit outstanding industrial potential, owing to their low prices.

2

Comparative study of copper sulfide hydrophobic textile treatment: hierarchical structures versus nanostructures

Almeda-Torres Cynthia, Reyes-Blas Hortensia, Hernandez-Paz Juan Francisco, Olivas-Armendariz Imelda, Villanueva-Montellano Alfredo, Rodriguez-Gonzalez Claudia Alejandra

Materials Science Poland

|

2025

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Vol. 43, No. 1

133--148

EN

This study compares membranes coated with hierarchical structures and copper sulfide nanostructures for water and oil separation. Copper was synthesized by a REDOX reaction, followed by sulfidation by a solid vapor method to produce copper sulfide hierarchical structures. A high-energy mechanical milling process was then applied to obtain copper sulfide nanostructures. Both types of copper sulfide structures were applied to cotton textiles by a dip coating method with varying copper sulfide concentrations (1–4%). The morphology of copper sulfide was characterized by scanning electron microscopy before and after milling, and the coated membranes were also analyzed to confirm the presence of polydimethylsiloxane (PDMS) and copper sulfide. Fourier transform infrared spectroscopy analysis confirmed the presence of PDMS and copper sulfide through their characteristic functional groups, while X-ray diffraction analysis confirmed the formation of the anilite phase. Membranes with hierarchical copper sulfide structures and copper sulfide nanostructures showed high hydrophobicity and stability through multiple filtration cycles. Contact angle measurements showed that copper sulfide nanostructure coatings provided a higher degree of hydrophobicity, achieving superhydrophobic angles of 155–165°, depending on the concentration. In contrast, membranes with hierarchical structures exhibited slightly lower hydrophobicity, with contact angles ranging from 146° to 154°. Filtration tests further supported these findings: membranes with copper sulfide nanostructures retained 96% efficiency even after ten cycles, while those with hierarchical structures dropped to 87%, underscoring the superior durability and performance of copper sulfide nanostructured membranes for separation applications.

3

Study of the Physicochemical Properties of Streptomyces Cell Surface and their Relationship with Soil Salinity of Origin

Zanane Chorouk, Mazigh Doha, Mitro Soukaina, Hakim Taoufik, Lekchiri Souad, El Othmany Rabha, El Louali Mostafa, Latrache Hassan, Zahir Hafida

Ecological Engineering & Environmental Technology

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2024

|

Vol. 25, iss. 10

31--43

EN

Physicochemical properties of the bacterial surface are involved in several interfacial phenomena, such as microbial adhesion. Ecology Soil salinity is a crucial parameter for the distribution of Streptomyces. The objective of this study was to investigate the impact of NaCl on the hydrophobicity and electron donor/acceptor characteristics of the cell surface of fourteen Streptomyces strains isolated from soils of the Beni Amir region (Morocco) with different salinities. The physicochemical properties of the surface were evaluated using the MATS (microbial adhesion to solvents) method at two concentrations of NaCl (0.1 M and 1.2 M). The results obtained show a significant change from hydrophilic to hydrophobic character. In particular, the Streptomyces lilaceus A53 strain showed the lowest variation (4.21%). On the other hand, the Streptomyces albogriseolus A65 strain presented the greatest variation (86.15%). These changes were observed when the salt concentration increased significantly from 0.1 M to 1.2 M NaCl. The electron donor/acceptor character systematically decreases and even becomes null for the majority of strains. Furthermore, a strong correlation between cell surface hydrophobicity and salinity of the original soil was observed with MATS at 1.2 M NaCl. This study highlighted the crucial importance of the NaCl concentration in the modulation of the physicochemical properties of the surface of Streptomyces bacteria.

4

Effect of Growth Medium Composition on the Physicochemical Surface Properties of Pseudomonas savastanoi, the Agent of Olive Tuberculosis

Mitro Soukaina, El Othmany Rabha, Hakim Taoufik, Zanane Chorouk, Lekchiri Souad, Mazigh Doha, El Louali Mostafa, Latrache Hassan, Zahir Hafida

Ecological Engineering & Environmental Technology

|

2024

|

Vol. 25, iss. 8

72--78

EN

Research into the formation of Pseudomonas savastanoi biofilms on olive trees is essential to prevent infections that induce tumour formation and damage tree health. To prevent the development of P. savastanoi biofilms, it is crucial to comprehend the factors influencing its adhesive behaviour. This research analysed the physicochemical properties of P. savastanoi in two types of media. P. savastanoi was cultivated in two media: nutrient agar (NA) and King B (KB), in solid and liquid forms. Wettability (θw), electron acceptor (γ+) electron donor (γ- ) properties, and surface free energy (ΔGiwi) are evaluated by contact angle measurements. The obtained results indicated that in solid media (NA and KB), P. savastanoi exhibited hydrophobic surface (𝜃WNA = 82.23°; 𝜃WKB= 94.9°), with strong electron donor (γNA− = 43.54 mJ.m-2; γKB− = 58.34 mJ·m-2) and mild electron acceptor (γNA+ = 0.32 mJ.m-2; γKB+ = 0.52 mJ·m-2) properties, along with negative surface free energy (ΔGiwiNA-76.13 mJ·m-2; ΔGiwiKB= -65.33 mJ·m-2. Conversely, in liquid media (NB and KB), the surface of P. savastanoi was generally hydrophilic (𝜃WNB= 55.43°; 𝜃WKB = 64.43°), with strong electron donor (γNB− = 29.23 mJ.m-2; γKB− = 41.38 mJ.m-2) and a surface free energy that registers as positive. Modification of the growth medium composition led to minor variations in P. savastanoi hydrophobicity and surface free energy. By understanding the factors involved in this adhesive behaviour, ecological methods to protect crops and contribute to more efficient environmental management and conservation of natural resources can be developed.

5

Effect of uv laser texturization on hydrophobic and anti-icing properties of waterborne polyurethane nanocomposite coatings

Przybyszewski Bartłomiej, Kozera Rafał, Ziętkowska Katarzyna, Labeda Anna, Karl Christian W., Pilz Monika, Boczkowska Anna

Composites Theory and Practice

|

2024

|

R. 24, nr 4

213--219

EN

Reducing ice buildup on different aerodynamic surfaces like airplane wings or wind turbine blades caused by the impact of supercooled water droplets can be achieved by creating surfaces featuring anti-icing capabilities. Hydrophobic surfaces are particularly promising due to their water-repelling attributes. In recent years, advancements in short-pulsed laser technolo gies have provided an efficient method for altering material surface properties. However, the effectiveness of such surfaces in preventing ice accumulation has yet to be validated. This study introduces a UV laser texturization approach for polymer sur faces. Laser patterning was employed to create periodic surface structures on the modified polyurethane coatings. The study investigated the influence of different laser parameters like pulse frequency, laser speed or pattern shape on the topographical features, hydrophobicity, and anti-icing properties of the resulting surfaces. Surface topography characterization was per formed using scanning electron microscopy (SEM) and an optical profilometer. The wettability parameters, including the stat ic contact angle and contact angle hysteresis, were measured to assess the impact of the wetting behavior and laser parameters on the materials under investigation. The anti-icing properties were evaluated by means of freezing delay time tests. The find ings indicate that the laser texturization of waterborne polyurethane coatings enhances the hydrophobic and anti-icing prop erties of the investigated materials.

6

The outer-membrane component of the multi-drug efflux system - a structural analysis based on hydrophobicity distribution

Roterman Irena, Konieczny Leszek, Stapor Katarzyna

Bio-Algorithms and Med-Systems

|

2024

|

Vol. 20, no. 1

1--14

EN

Aim: The structure of a multi-drug efflux system (specifically the outer membrane part) is the focus of our analysis. The role of electrostatic interactions in the efflux process is well understood. Methods: Our analysis is made possible by the application of the fuzzy oil drop model in its modified form (FOD-M). Results: The distribution of hydrophobicity in the periplasmic and membrane domains plays a significant role in both stabilisation within the membrane and in tunnel formation, which facilitates the transport of antibiotics. Conclusions: The analysis presented in this paper reveals the specificity of hydrophobicity distribution in relation to biological activity, as well as a possible mechanism for the folding process of proteins involved in multi-drug efflux.

7

Use of Glyoxal in Starch Based Sizing Mixture for Surface Modification of Paper

Akin Ayse Ebru, Canbolat Doğan, Ondaral Sedat

Drewno : prace naukowe, doniesienia, komunikaty

|

2023

|

Vol. 66, nr 211

Art. no. 1644-3985.444.09

EN

Starches have been used as the surface sizing or coating material to enhance the strength and surface properties of paper. The main mechanisms behind their performance are physical and chemical interactions between cellulosic fibres and starches. In this study, the usage of glyoxal in an oxidized starch-based sizing mixture was studied to improve the chemical crosslinking due to the additional hydrogen and acetal bonds. The performance of glyoxal on starch sizing formula containing oxidized starch, styrene acrylate and polyaluminium chloride were studied in terms of water resistance and mechanical properties of paper. The results showed that the water absorption values (Cobb60) decreased by 32% when adding glyoxal to paper coated with the reference solution, which contained only a styrene acrylate copolymer. Additionally, with this newly formulated surface sizing application, the tensile strength of the papers increased by about 16% compared with the reference.

8

Electrokinetic and surface properties of some methacrylate-based copolymers

Ersoy Bahri, Çiftçi Hakan, Evcin Atilla, Merdivenci Yılmaz

Physicochemical Problems of Mineral Processing

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2022

|

Vol. 58, iss. 5

art. no. 152162

EN

In this study, some electrokinetic and surface properties of MBAOM-GMA copolymers synthesized from 2-[(methoxy-1,3-benzothiazole-2-yl) amino]-2oxoethyl methacrylate (MBAOM) and glycidyl methacrylate (GMA) monomers were investigated. Accordingly, (i) pH-dependent zeta (ζ) potential changes of the copolymers were investigated under a constant ionic strength (in 1.10-3mol/dm3 NaCl) and the corresponding isoelectric points (iep) were determined, (ii) zeta potential changes depending on the salt concentration in the presence of mono-, di- and tri-valent metal salts were examined, (iii) contact angles (θ) of the copolymers with water were measured and their wetting behavior was assessed, and (iv) surface free energies (SFE) of the copolymers were determined by Acid-Base approach using Van Oss-Chaudhury-Good method. The compositions of the copolymers were 77% MBAOM - 23% GMA, 45% MBAOM - 55% GMA, and 19% MBAOM - 81% GMA. FeCl3, CaCl2, and KCl salts were used for the salt solutions for the zeta potential measurements. As a result, (i) it was determined that the chemical structure of methacrylate copolymers showed a decisive effect on both electrokinetic and surface properties, (ii) the hydrophobic character of copolymer increased with the increase of the GMA ratio, and correspondingly, the SFE decreased, and (iii) the iep of the copolymers varied between pH 3.1-3.7 depending on composition.

9

Control of glass surface wettability via esterification with n-alkyl alcohols

Kruszelnicki Mateusz, Polowczyk Izabela, Kowalczuk Przemyslaw B.

Physicochemical Problems of Mineral Processing

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2022

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Vol. 58, iss. 2

art. no. 145147

EN

Surface wettability plays an essential role in many processes and materials applications. It depends mainly on the surface roughness and chemical composition, thus through a controlled modification of these parameters, the wettability can be restrained. Glass is an inorganic solid material, composed mainly of amorphous silica, which surface, due to the presence of reactive hydroxyl groups, can be quite easily chemically modified. This feature can be used to control the wettability of glass by reaction with organic compounds. In this study, the esterification of glass silanol groups with n-alkyl alcohols (Cn/H2n+1/OH, n=3, 4, 6, 8, 10) was employed to modify its wettability. The effect of such modification on the physicochemical properties of glass surface was comprehensively investigated and characterised by the water contact angle, surface free energy, zeta potential, atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) measurements. We demonstrate that the wettability of the esterified glass surface is strongly dependent on both the chain length of used alcohol and modification time. The alcohol molecule binds to the glass surface through a Si-O-C bond, leading to the formation of a monolayer that does not significantly affect the surface morphology and zeta potential. Conducted studies provided a broader view of the influence of this technique for modifying surface wettability on its physicochemical properties.

10

Perspektywy rozwoju technik hydrofobizacji papieru

Ganicz Tomasz

Przegląd Papierniczy

|

2021

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R. 77, nr 1

53--61

PL

Materiały celulozowe o powierzchniowej hydrofobowości i właściwościach barierowych dla wody stanowią coraz większy odsetek rynku papierniczego, co wynika w dużym stopniu ze zmian struktury handlu detalicznego oraz środowiskowych regulacji prawnych. Niniejsza praca omawia stan legislacji europejskiej w tym zakresie oraz dokonuje przeglądu współczesnej literatury naukowej, opisującej nowe zastosowania tradycyjnych metod, nowych obiecujących technologii do zastosowań masowych, a także propozycji nadawania właściwości superhydrofobowych i kombinacji hydrofobowych z innymi właściwościami. Potencjalnie może to znaleźć zastosowania niszowe, takie jak: specjalne metody zabezpieczania banknotów, medyczne testy diagnostyczne i elektronika mikroprzepływowa.

EN

Cellulose materials with surface hydrophobicity and water barrier properties constitute an increasing percentage of the paper market. It is largely due to changes in the structure of retail trade and environmental legal regulations. This paper discusses the state of European legislation in this area and contemporary literature describing new applications of traditional methods, new promising technologies for mass applications as well as attempts of imparting superhydrophobic properties and combinations of hydrophobicity with other properties. These could potentially find niche applications such as special security methods for banknotes, medical diagnostic tests or microfluidic electronics.

11

Growth Temperature Effect of Atomic-Layer-Deposited GdOx Films

Ryu Sung Yeon, Yun Hee Ju, Lee Min Hwan, Choi Byung Joon

Archives of Metallurgy and Materials

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2021

|

Vol. 66, iss. 3

755--758

EN

Gadolinium oxide (Gd2O3) is one of the lanthanide rare-earth oxides, which has been extensively studied due to its versatile functionalities, such as a high permittivity, reactivity with moisture, and ionic conductivity, etc. In this work, GdOx thin film was grown by atomic layer deposition using cyclopentadienyl (Cp)-based Gd precursor and water. As-grown GdOx film was amorphous and had a sub-stoichiometric (x ~ 1.2) composition with a uniform elemental depth profile. ~3 nm-thick GdOx thin film could modify the hydrophilic Si substrate into hydrophobic surface with water wetting angle of 70°. Wetting and electrical test revealed that the growth temperature affects the hydrophobicity and electrical strength of the as-grown GdOx film.

12

Effect of particle properties on rheology of low-concentration coal suspensions

Hou Jinying, Ma Xiaomin, Fan Yuping, Dong Xianshu, Yao Suling

Physicochemical Problems of Mineral Processing

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2020

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Vol. 56, iss. 5

984--995

EN

In wet coal preparation, the products of some processes are transported as low-concentration suspensions. Their rheology is greatly affected by the properties of the coal particles that result from the formation and weathering during preparation. In this study, the properties of coal particles, including volumetric properties (i.e., solids content, granularity, and clay mineral fraction) and surface characteristics (i.e., dynamic potential, degree of coalification, and degree of surface oxidization), were studied to determine their effects on the apparent viscosity of low-concentration coal suspensions. With increasing solids content and smaller particle size in the suspension, the interactions between the coal particles became stronger due to the increased particle content, thus increasing the coal suspension’s apparent viscosity. Adding clay minerals to the suspension gradually changed its composition and structure and increased its viscosity. The dynamic potential of the coal particles and inter-particle electrostatic repulsive forces were reduced with the addition of Ca2+ ions, and the coal particles collided and aggregated, which increased the apparent viscosity of the suspension. For coal with a low degree of coalification or coal had been oxidized by a hydrogen peroxide solution, the suspension of the hydrophilic coal particles was associated with a lower apparent viscosity than that of highly hydrophobic solids, which tended to aggregate and form flocculent masses.

13

The Hydrophobization of a Nanofiber Layer Using Low-Vacuum Plasma

Knížek Roman, Knížková Denisa, Bajzík Vladimír

Autex Research Journal

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2020

|

Vol. 20, no. 4

524--529

EN

Nanofiber materials offer a wide range of use in various production fields, e.g., different types of filtration, or areas requiring high hydrostatic resistance. They are made from different polymers, some of which are more hydrophobic than others, for instance some types of polyurethanes and polyvinylidene fluoride. However, even these polyurethanes cannot guarantee a high hydrophobicity of the final nanofiber material. To increase this desired property, we have to use the so-called hydrophobic substances like fluorocarbon. The nanofiber layer has to be prepared so that its pores do not get blocked, which would worsen its filtration capability and air permeability. This is why a roll-to-roll low-vacuum plasma was used in our case for creating a fabric with nanofiber layer for the clothing industry. The result is a nanofiber material with a hydrostatic resistance higher than a 15,000 mm water column. Under suitable conditions, we can produce a nanofiber membrane for clothing with thermophysiological properties similar to those of membranes produced with different principles, e.g., nanoporous membranes. The nanofiber membrane provides us desirable properties such as stability during repeated washing.

14

Surface properties of the doped silica hydrophobic coatings deposited on plasma activated glass supports

Chodkowski Michał, Terpiłowski Konrad, Goncharuk Olena

Physicochemical Problems of Mineral Processing

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2019

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Vol. 55, iss. 6

1450--1459

EN

The paper discusses preparation and characteristics of silica hydrophobic layers deposited on the plasma-modified glass supports. The surfaces were investigated using wettability measurements, profilometry, photoacoustic and infrared spectroscopy, X-ray photoelectron spectroscopy as well as scanning electron microscopy. The wettability measurements showed that the obtained surfaces are hydrophobic – the water contact angle was in the range of 140-150 degrees. The photoacoustic and infrared spectroscopy as well as X-ray photoelectron spectroscopy disclosed the surface compositions, particularly that of the hydrophobic alkyl groups deposited on them. They were methyl groups introduced during hydrophobization by hexamethyldisilazane. In addition, it was found that the number of groups on the surface depends on the kind of plasma by which the supports were activated. The optical profilometer showed differences in the surface roughness which affects their hydrophobicity. Moreover, the surface free energies were determined using the contact angle hysteresis method. They disclosed differences in each surface, depending on the way of supports activation. The largest hydrophobicity was obtained on the layer deposited on the support activated by the argon plasma. However, support activation by the air plasma resulted in a decrease of hydrophobicity compared to that of the non-activated surface.

15

Metahydrophobicity and orthohydrophilicity tested in flotation of NaCl, KCl, KPF6 in their saturated aqueous solutions

Drzymala Jan, Dubiel Malgorzata, Ratajczak Tomasz

Physicochemical Problems of Mineral Processing

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2019

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Vol. 55, iss. 5

1141--1147

EN

Flotation tests of different size fractions of NaCl, KCl and KPF6 in their saturated aqueous solutions were performed in a 36 cm in height monobubble Hallimond tube. Also contact angle tests by means of sessile drops of saturated salt solution put on pressed discs of salts were carried out. The obtained sessile drop contact angles were equal to zero, pointing to a complete hydrophilicity (orthophilicity) of the investigated salts. In the case of NaCl and KCl, their orthohydrophilicity was confirmed by flotation tests and flotometric considerations because the entrainment factors, which take into account the maximum size of entrained particles and density of the salt as well as it solution, were similar to those of quartz and magnetite and equal to 0.11 mm. The entrainment factor for KPF6 was equal to 0.18 mm and was greater than that of NaCl and KCl indicating certain natural flotation of this salt caused by some flotational hydrophobicity called in this paper metahydrophobicity. The metahydrophobicity of KPF6 was confirmed by flotation results. In the case of KPF6 the maximum yields of the same size particles were the highest, even though the density of this salt was greater than that of NaCl and KCl. Also, the first order kinetic constants were always the greatest for KPF6. Further flotometeric calculation based on the balance of forces involved in flotation indicated that the estimated contact angle of KPF6 was about 8 º assuming static flotation, and 7 º for dynamic flotation, while for NaCl and KCl was below 5 º . It means that during flotation test orthohydrophilic NaCl and KCl are only entrained while for metahydrophobic KPF6 there is mostly entrainment and some flotation.

16

Difference in flotation behavior of galena by single and multi-step chronoamperometric oxidation

Ozdemir Orhan, Hampton Marc A, Nguyen Tuan, Nguyen Anh

Physicochemical Problems of Mineral Processing

|

2019

|

Vol. 55, iss. 3

812--821

EN

The relationship between electrochemical oxidation (Chronoamperometry) of galena surfaces and collocterless galena flotation was investigated in detail. The chronoamperometry (CA) micro- flotation experiments and zeta potential experiments were performed with ground galena particles (106×53 μm). In addition, contact angle measurements were carried out with a freshly cleaved galena sample at pH 4 in order to investigate any changes in galena surface hydrophobicity after the surface oxidation electrochemically. The results from this study indicated that there is a strong link between the nano/micro-physico-chemical properties of a sulphide on galena surfaces and collectorless flotation of galena particles at pH 4. The results were also supported with the electrokinetics behavior and contact angle values of galena particles.

17

Density functional theory study of H2O adsorption on different sphalerite surfaces

Deng Zheng-bin, Tong Xiong, Huang Ling-yun, Xie Xian

Physicochemical Problems of Mineral Processing

|

2019

|

Vol. 55, iss. 1

82--88

EN

Effects of In, Ge, Fe substitution in the lattice of sphalerite on wettability were usually ignored, therefore the optimal flotation condition could be difficult to find due to lacking of sufficient theoretical study on water adsorption, resulting lower recoveries of different sphalerites. Adsorption of H2O on different sphalerite surfaces was studied using density functional theory (DFT) method. All computational models were built in a vacuum environment to eliminate the effects of oxygen and other factors. H2O molecule prefers to stay with ideal sphalerite, indium-beard sphalerite, germanium-beard sphalerite and marmatite surfaces rather than water. Compared with ideal sphalerite surface, Fe atom improves the hydrophilicity of surface, while In and Ge atoms reduce the hydrophilicity.

18

Influence of High-Voltage Electromagnetic Pulses on Technological Properties of Diamond Crystals and Kimberlite Rock-Forming Minerals

Anashkina N. E., Bunin Igor Zh., Khachatryan G. K.

Inżynieria Mineralna

|

2019

|

R. 21, nr 1/2

133--138

EN

For optimization of diamond processing technology the influence of nanosecond high voltage pulses on mechanical and technological properties of diamond crystals and kimberlite rock-forming minerals (calcite, olivine, serpentine) was investigated. Using methods of Fourier Transform Infrared Spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), microscopy and mikrohardness measurement the changes of structural, physic-chemical surface properties, and microhardness of minerals as the result of impacts, was studied. Non-thermal impacts caused a decrease of kimberlite rock-forming minerals microhardness in general to 40–66% as the result of surface microstructure destruction which is caused by formation of micro cracks, traces of surface breakdown and other defects. At the same time, the pulse energy impact on natural diamonds led to formation of B2 type crystal lattice microsift defects, elevated concentration of which increases the hardness properties of crystals. The obtained result indicates possibility of applying pulsed energy effects to improve the softening efficiency of diamond-bearing kimberlites rock-forming minerals without damaging the diamond crystals and ensuring their preservation by the subsequent grinding of ores. The effect of increasing the natural diamonds flotation activity by 14% (from 47% to 61%) was experimentally established as a result of processing diamond crystals with nanosecond pulses (~ 10–50 sec), which indicates the principal possibility of using pulsed energy impacts to intensify the diamond flotation during processing diamond-bearing kimberlites.

PL

W celu optymalizacji technologii przeróbki diamentów zbadano wpływ impulsów wysokiego napięcia nanosekundowego na właściwości mechaniczne i technologiczne kryształów diamentu i minerałów tworzących skały kimberlitowe (kalcyt, oliwin, serpentynit). Przy pomocy metod spektroskopii w podczerwieni z transformacją Fouriera (FTIR), rentgenowskiej spektroskopii fotoelektronowej (XPS), mikroskopii i pomiaru mikrotwardości badano zmiany strukturalnych, fizykochemicznych właściwości powierzchni oraz mikrotwardości minerałów w wyniku uderzeń. Uderzenia nietermiczne spowodowały zmniejszenie mikrotwardości minerałów tworzących skały kimberlitowe ogólnie do 40–66% w wyniku zniszczenia mikrostruktury powierzchni, spowodowanego powstawaniem mikropęknięć, śladów rozpadu powierzchni i innych wad. Jednocześnie wpływ energii impulsu na naturalne diamenty doprowadził do powstania defektów mikroprzesunięcia sieci krystalicznej typu B2, których podwyższone stężenie zwiększa właściwości twardości kryształów. Uzyskany wynik wskazuje na możliwość zastosowania efektów pulsacji energii w celu poprawy wydajności zmiękczania zawierających diamenty minerałów tworzących skały jak kimberlity, bez uszkadzania kryształów diamentu i zapewnienia ich zachowania w czasie późniejszego mielenia rudy. Efekt zwiększenia naturalnej aktywności flotacyjnej diamentów o 14% (z 47 do 61%) ustalono eksperymentalnie w wyniku przetwarzania kryształów diamentu za pomocą impulsów nanosekundowych (~ 10–50 sekund), co wskazuje na główną możliwość wykorzystania energii pulsacyjnej. Impulsy wpływają na intensyfikację flotacji diamentów podczas przetwarzania kimberlitów zawierających diamenty.

19

Aggregation-promoting conditions necessary to create the complexes by acylphosphatase from the hyperthermophile Sulfolobus solfataricus

Banach Mateusz, Wiśniowski Zdzisław, Ptak Magdalena, Roterman Irena

Bio-Algorithms and Med-Systems

|

2019

|

Vol. 15, no. 2

art. no. 20190023

EN

The structural transition from the globular to the amyloid form of proteins requires aggregation-promoting conditions. The protein example of this category is acylphosphatase from the hyperthermophile Sulfolobus solfataricus. This protein represents a structure with a well-defined hydrophobic core. This is why the complexation (including oligomerization) of this protein is of low probability. The chain fragment participating in aggregation in comparison to the status with respect to the fuzzy oil drop model is discussed in this paper.

20

Oznaczenie stanów energetycznych powierzchni zgłębnika żołądkowego po wybranych procesach starzenia materiału

Chrobak Aleksandra, Cieślik Magdalena, Jaśko Klaudia, Kuras Ilona, Łagan Sylwia

Aktualne Problemy Biomechaniki

|

2019

|

z. 17

19--25

PL

Celem pracy była ocena wpływu procesu starzenia zgłębnika żołądkowego na właściwości powierzchni określona w oparciu o pomiary kątów zwilżania. Oznaczono poziom chłonności materiału pod wpływem działania środowiska wodnego (woda: 23ºC/24h oraz 100º/h, 0,9% roztwór NaCl: 37ºC/48h, roztwór Nestle Health Science Isosource Energy: 37ºC/48h). Zidentyfikowano swobodną energię powierzchniową oraz jej składowe wykorzystując dwa modele analityczne (Owensa-Wendta oraz van Ossa-Chauhury-Gooda). W rezultacie przyspieszonego starzenia ujawniono zmiany właściwości powierzchni zgłębnika.

EN

The aim of this work was to assess the influence of the stomach tube aging process on surface properties determined based on measurements of contact angles. The level of absorbency of the material under the influence of the water environment was determined (water: 23ºC / 24h and 100º / h, 0.9% NaCl solution: 37ºC / 48h, Nestle Health Science Isosource Energy: 37ºC/48h). The surface free energy and its components were identified using two analytical models (Owens-Wendt and van Oss-Chauhury-Good). As a result of aging accelerated aging, changes in the surface properties of the stomach tubes were revealed.