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The purpose of this study is to prepare a polydopamine (PDA)–palygorskite (Pal) hybrid-reinforced epoxy coating with high adhesion strength on wet concrete surface.

One synthetic step was adopted to prepare novel PDA–Pal hybrid epoxy coating. The process and product were analyzed and confirmed by FIRT, thermogravimetric analysis and scanning electron microscopy. The mass fraction of PDA–Pal hybrid affecting the adhesion strength of epoxy coating was analyzed and confirmed by pull-off test.

PDA–Pal hybrid mass fractions of 0, 1, 3 and 5 were added to the coatings. For a 5 Wt.% PDA–Pal hybrid content, the adhesive strengths on the saturated or underwater concrete surfaces increased to 4.0 and 2.5 MPa, respectively. In addition, the tensile mechanical property of the epoxy coating improved significantly after PDA–Pal addition.

This new epoxy coating hybrid by PDA–Pal could be applied as a concrete protective layer near water or in wet or damp environments.

Introduction of PDA–Pal hybrid to prepare epoxy coating with high adhesion strength on wet concrete surface has not been systematically studied previously.

This paper aims to characterize the mineral composition of Martian surfaces based on Thermal Emission Spectrometer (TES; Mars Global Surveyor) as measured in the infrared thermal range. It presents modeling and interpreting of TES spectral data from selected Martian regions from which the atmospheric influences had been removed using radiative transfer algorithm and deconvolution algorithm. The spectra from the dark area of Cimmeria Terra and the bright Isidis Planitia were developed in Philip Christensen’s and Joshua Bandfield’s publications, where these spectra were subjected to spectral deconvolution to estimate the mineral composition of the Martian surface. The results of the analyses of these spectra were used for the modeling of dusty and non-dusty surface of Mars. As an additional source, the mineral compositions of Polish basalts and mafic rocks were used for these surfaces as well as for modeling Martian meteorites Shergottites, Nakhlites and Chassignites. Finally, the spectra for the modeling of the Hellas region were obtained from the Planetary Fourier Spectrometer (PFS) – (Mars Express) and the mineralogical compositions of basalts from the southern part of Poland were used for this purpose. The Hellas region was modeled also using simulated Martian soil samples Phyllosilicatic Mars Regolith Simulant and Sulfatic Mars Regolith Simulant, showing as a result that the composition of this selected area has a high content of sulfates. Linear spectral combination was chosen as the best modeling method. The modeling was performed using PFSLook software written in the Space Research Centre of the Polish Academy of Sciences. Additional measurements were made with an infrared spectrometer in thermal infrared spectroscopy, for comparison with the measurements of PFS and TES. The research uses a kind of modeling that successfully matches mineralogical composition to the measured spectrum from the surface of Mars, which is the main goal of the publication. This method is used for areas where sample collection is not yet possible. The areas have been chosen based on public availability of the data.

The infrared spectra of the Martian surface were modeled by applying the linear combination of the spectra of selected minerals, which then are normalized against the measured surface area with previously separated atmosphere. The minerals for modeling are selected based on the expected composition of the Martian rocks, such as basalt. The software used for this purpose was PFSLook, a program written in C++ at the Space Research Centre of the Polish Academy of Sciences, which is based on adding the spectra of minerals in the relevant percentage, resulting in a final spectrum containing 100 per cent of the minerals.

The results of this work confirmed that there is a relationship between the modeled, altered and unaltered, basaltic surface and the measured spectrum from Martian instruments. Spectral deconvolution makes it possible to interpret the measured spectra from areas that are potentially difficult to explore or to choose interesting areas to explore on site. The method is described for mid-infrared because of software availability, but it can be successfully applied to shortwave spectra in near-infrared (NIR) band for data from the currently functioning Martian spectroscopes.

This work is the only one attempting modeling the spectra of the surface of Mars with a separated atmosphere and to determine the mineralogical composition.

The purpose of this paper is to investigate the effect of reciprocating and unidirectional sliding motions on friction and wear of phenolic resin-based composite.

The phenolic resin-based composite was fabricated by hot press molding, and then the tribological properties were tested on a CSM tribometer with two types of friction motion modes – reciprocating friction and unidirectional friction.

The results showed that the composite exhibited low friction coefficient in unidirectional test. However, the wear factor recorded under unidirectional sliding condition was 12-16 times higher than the reciprocating friction results. The SEM and optical microscopy test results showed that changing the relative motion mode resulted in different topography of transfer film, which is responsible for the different friction and wear characteristics of the composite under reciprocating and unidirectional friction conditions.

Effect of different friction modes, reciprocating friction and unidirectional friction, on friction characteristics of the composite is sought. Different topography of transfer film formed under reciprocating and unidirectional friction conditions contributed to the different friction characteristics.

The purpose of this paper is to demonstrate the strategy for increasing the applicability of material extrusion additive manufacturing (AM) technologies, based on fused deposition modeling (FDM), through the development of materials with targeted physical properties. Here, the authors demonstrate materials specifically developed for the manufacture of electromechanical and electromagnetic applications, the use of FDM-type processes in austere environments and the application of material extrusion AM.

Using a twin screw polymeric extrusion process, novel polymer matrix composites and blends were created where the base material was a material commonly used in FDM-type processes, namely, acrylonitrile butadiene styrene (ABS) or polycarbonate (PC).

The work presented here demonstrates that, through targeted materials development, the applicability of AM platforms based on FDM technology can be increased. Here, the authors demonstrate that that the physical properties of ABS and PC can be manipulated to be used in several applications such as electromagnetic and X-ray shielding. Other instances of the development of new materials for FDM led to mitigation of problems associated with the process such as surface finish and mechanical property anisotropy based on build orientation.

This paper is an overview of a research effort dedicated to increasing the amount of material systems available to material extrusion AM. Here materials development is shown to not only increase the number of suitable applications for FDM-type processes, but to be a pathway toward solving inherent problems associated with FDM such as surface finish and build orientation-caused mechanical property anisotropy.

The paper aims to evaluate drying performance of earth mortar by solar drying for more durability, minimize pathologies in traditional construction and determine the influence of temperature and humidity on the microstructure of earth mortar using static gravimetric method.

A convective solar dryer was used for the pretreatment of building and solid materials for construction.

The humidity influences the mortar sorption – surface water sorption of earth mortar increased with increasing temperature.

The study used a novel method for pretreatment building materials by using solar dryer.

The tribological properties of muscovite and its thermal-treated products as lubricant additives in lithium grease were investigated. The effect of thermal temperature on the crystal structure and tribological properties of muscovite was studied. This study aims to explore the tribological mechanism of muscovite and optimize a proper thermal activation temperature, thus further improving the tribological properties.

The crystal structure of muscovite samples was characterized by SEM, TG-DSC, XRD and FTIR. The tribological properties of grease samples were investigated using a four-ball tribotester and the worn surface was analyzed by SEM and EDS.

The excellent tribological properties of muscovite can be ascribed to the layer structure and lubricant film formed on the worn surface. Thermal temperature at 500-600°C increases the surface activity and oxygen releasing capability, and thus favors the formation of lubricant film and accordingly further improves the tribological properties. However, the layer structure is destroyed and hard phases such as alumina and amorphous appear after thermal temperature activated beyond 1000°C, as it results in the aggravation of friction and wear.

To the authors’ knowledge, it is the first to study the effect of thermal temperature on the crystal structure and tribological properties of muscovite. The tribological mechanism of muscovite particle and its thermal-treated products was disclosed.

Kaolin is a soft, white mineral mainly composed of coarse‐ to fine‐grained, plate‐like aluminum silicate particles. As kaolin assists with desired rheological properties that help maintain proper dispersion and provide bulk to the product, it is used as an important extender in paint manufacture. It can be used to reduce the amount of expensive pigments, such as titanium dioxide. In spite of these uses, kaolin has the disadvantage of having coarse particles and low hiding power. The purpose of this paper is to introduce a new class of pigments based on kaolin as a core and titanium dioxide as the shell.

In the work reported in this paper, kaolin was used as a core covered with a surface layer of titanium dioxide comprising the shell in order to combine their properties and get over kaolin's disadvantages, besides enhancing its corrosion protection properties. The pigments prepared were characterised using X‐ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Deposition of titanium dioxide on the surface of kaolin was confirmed by Energy‐dispersive X‐ray analysis (EDAX) and X‐ray fluorescence (XRF) techniques. Pigment properties were estimated according to American standard testing methods (ASTM) methods and then were incorporated in anticorrosive paint formulations based on medium oil alkyd resin. The physico‐mechanical and corrosion properties of dry paint films were determined according to ASTM methods.

The tests revealed that the concentration of titanium dioxide layer deposited on kaolin surface was inversely proportional to the anticorrosive behaviour of these pigments.

The pigments can be applied in other polymer composites, e.g. rubber and plastics as filler and reinforcing agent.

The pigments prepared are eco‐friendly that can replace other expensive pigments. These pigments can compensate for the presence of titanium dioxide in paint formulations successfully, and thus lower the costs. The main advantage of these pigments is that they combine the properties of both of their counterparts, they are of lower cost, and they also overcome the disadvantages of both its counterparts, e.g. low hiding power of kaolin, photochemical activity of titanium dioxide. Also, they can be applied in other industries other than paints, e.g. paper, rubber and plastics composites.

The purpose of this study is to improve the dispersion of nanoserpentine modified with OA, KH550 and KH550/oleic acid in lubricating oil. The main aims are to analyze the influence of the dispersion and stability of nanoserpentine modified by different modifiers on the friction properties of lubricating oil.

The nanoserpentine particles obtained by ball-milling were modified by silane coupling agent KH550, OA and KH550/OA, respectively. The dispersity and stability of nanoserpentine in base lubricating oil were characterized by the absorbance value method, centrifuge precipitation rate method and static observation method. The MMU-5G screen display friction and wear tester was used to evaluate the tribological properties of C45E4/C45E4 friction pairs in corresponding lubricating oils. The surface morphology of the friction pairs was observed by scanning electron microscopy and energy dispersive spectroscopy.

The results showed that the dispersity and stability of nanoserpentine particles in lubricating oil were best modified by OA, followed by the KH550/OA and finally, the KH550. Nanoserpentine particles modified with oleic acid showed optimum tribological properties as lubricant additives.

This study can improve the dispersion stability of nanoserpentine particles in lubricating oil, increasing the antiwear and antifriction performance of lubricating oil, which has great significance in economic and military aspects.

The purpose of this paper is to synthesise a disperse dye based on benzisothiazole and to characterise its crystal morphology, dispersing stability, to study the relationship between the chemical structure and the dyeing property of the dye.

The disperse dye based on benzisothiazole, 3-(3-methyl-4-N-ethyl-N-benzyl-phenyldiazenyl)-5-nitro-2,1-benzisothiazoles, was synthesized. The disperse dye based on benzisothiazole, 3-(3-methyl-4-N-ethyl-N-benzyl-phenyldiazenyl)-5-nitro-2,1-benzisothiazoles, was synthesised. The chemical structure of the dye obtained was characterised by infrared spectrum Fourier transform infrared spectroscopy and nuclear magnetic resonance (1HNMR), and the crystal morphology was observed by Field Emission Scanning Electron Microscopy. Sodium salt of polycondensated naphthalenesulphonic acid (dispersing agent sodium salt of polycondensated naphthalenesulphonic acid [MF]) and a sulphonated amino polyether (anionic surfactant B600) were employed to grind and disperse the dye crystals. The dispersion property of the dye particles was characterised. Dyeing property of the dispersion system was also studied.

The dye formed spherical crystals that were made up of a large number of acicular crystals similar to spherical chrysanthemum. The crystals had warping crystal centres inside the spheres. The particle sizes of the dispersion with the mixture of B600 and MF had an uniform distribution and were smaller than that of the dispersion with only single dispersing agent MF. Dyeing with the dispersion system had an excellent reproducibility under alkalinic condition.

An alkalinic dyeing method for poly(ethylene terephthalate) (PET) with disperse dyes as a cleaner wet process had been developed. Such a process combined pretreatment and dyeing process using the alkali-stable disperse dyes and reduced the consumption of water and energy and improved production efficiency.

The crystal morphology, dispersion and dyeing properties of the synthesised disperse dye for dyeing PET fabric under alkalinic condition were discussed. This disperse dye has an important potential application in alkalinic dyeing method.

Kaolin is a soft white mineral which has a large array of uses. It is most commonly referred to as “China clay”. Sources of this mineral can be found all over the world, its uses are multiple and diverse. It is a mineral belonging to the group of alumino‐silicates with the chemical composition Al2Si2O5(OH)4. It is white, soft, plastic clay mainly composed of plate‐like particles. It is a unique industrial mineral, which remains chemically inert over a relatively wide pH range. The purpose of this paper is to study the difference in performances of untreated or natural kaolin, thermally treated kaolin or so‐called “calcined kaolin” and chemically treated kaolin using ammonium molybdate to convert the γ‐Al2O3 naturally found in kaolin to α‐Al2O3 which possesses one of the most known stable crystalline phases (corundum) in alkyd based anticorrosive paint formulations used for protection of steel.

The different kaolins were characterized using different analytical and spectro‐photometric techniques. The pigments were characterized using X‐ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Evaluation of these pigments using international standard testing methods (ASTM) was estimated. The extender pigments were then incorporated in solvent‐based paint formulations based on medium oil‐modified soya‐bean dehydrated castor oil alkyd resin. The physico‐mechanical properties of dry films and their corrosion properties using accelerated laboratory test in 3.5% NaCl for 28 days were tested.

The results of this work revealed that calcined kaolin was better in its performance in protection of steel than kaolin, while chemically treated kaolin varied in its performance according to the concentration of modifier or dopant.

Kaolin has a large array of uses. These pigments can be applied in other polymer composites, e.g. rubber and plastics as reinforcing agent.

The untreated and treated kaolins are environmentally friendly pigments which can impart high anticorrosive behaviour to paint films with concomitant cost saving.