This paper presents the effect of modified halloysite nanotubes on the sustained drug release mechanisms of sodium salicylate. Acid treatment and composite polymer-halloysite modification techniques were adopted in this study. After each modification, sodium salicylate drug was loaded, and in vitro release properties were evaluated and compared with the raw unmodified halloysite nanotubes. The results obtained from SEM, TEM and FTIR analyses indicate that both acid treatment and composite formation have no effect on the tubular structure and morphology of halloysite. However, modification of the halloysite nanotubes did influence the drug release rate. In the acid treatment modification, there was an improved loading of sodium salicylate drug which resulted in the sustain release of large amount of the sodium salicylate. In the polymer/halloysite composite formation, a consistent layer of polymer was formed around the halloysite during the composite formation and thus delayed release providing sustained release of sodium salicylate drug over a longer period of time as compared to the acid treated and unmodified halloysite. The results from the invitro release were best fitted with the Higuchi and the Koresymer-Peppas models.

Since the forming of the microstructure depends on the specific of the casting method, which directly affects further mechanical and physical properties of the material, it is important to understand how to control the microstructure of the cast to understand changes that taking place during the crystallisation process. For estimating the metallurgical quality of the liquid metal before casting, the thermal-derivative analysis (TDA) is utilised. The TDA has been used for a long time, in both ferrous and non-ferrous industries casting. The Universal Metallurgical Simulator and Analyser (UMSA) platform is a rapid, sensitive and economical method of determining a full range of solidification features. The work focuses on the thermal analysis and heat treatment of aluminium alloys. The liquidus and solidus temperatures and dendrite coherency point (DCP) are then characterised. The research shows that the UMSA platform allows precise determination and calculation of thermal parameters. The influence of the heat treatment on structure and properties of aluminium castings has been determined as well. Heat treatment was carried out to increase the mechanical properties of aluminium alloys.Based on the findings above, the influence of microstructure on properties of the alloys is discussed.

The paper presents the results of the properties of flame sprayed ceramic coatings using oxide ceramic materials coating of a powdered aluminium oxide (Al2O3) matrix with 3% titanium oxide (TiO2) applied to unalloyed S235JR grade structural steel. A primer consisting of a metallic Ni-Al-Mo based powder has been applied to plates with dimensions of 5×200×300 mm and front surfaces of Ø40×50 mm cylinders. Flame spraying of primer coating was made using a RotoTec 80 torch, and an external coating was made with a CastoDyn DS 8000 torch. Evaluation of the coating properties was conducted using metallographic testing, phase composition research, measurement of microhardness, substrate coating adhesion (acc. to EN 582:1996 standard), erosion wear resistance (acc. to ASTM G76-95 standard), and abrasive wear resistance (acc. to ASTM G65 standard) and thermal impact. The testing performed has demonstrated that flame spraying with 97% Al2O3 powder containing 3% TiO2 performed in a range of parameters allows for obtaining high-quality ceramic coatings with thickness up to ca. 500 µm on a steel base. Spray coating possesses a structure consisting mainly of aluminium oxide and a small amount of NiAl10O16 and NiAl32O49 phases. The bonding primer coat sprayed with the Ni-Al-Mo powder to the steel substrate and external coating sprayed with the 97% Al2O3 powder with 3% TiO2 addition demonstrates mechanical bonding characteristics. The coating is characterized by a high adhesion to the base amounting to 6.5 MPa. Average hardness of the external coating is ca. 780 HV. The obtained coatings are characterized by high erosion and abrasive wear resistance and the resistance to effects of cyclic thermal shock.

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In this work selected results of investigations of the new AlMg1SiCu matrix composite materials reinforced with halloysite particles manufactured by powder metallurgy techniques including mechanical alloying and hot extrusion are present. The composite materials obtained as a result of mechanical synthesis and hot extrusion are characterized with the structure of evenly distributed, disperse reinforcing phase particles in fine-grain matrix of AlMg1SiCu alloy, facilitate the obtainment of higher values of strength properties, compared to the initial alloy. The nanostructural composite materials reinforced with halloysite nanotubes with 15 mass % share are characterized by almost twice as higher micro-hardness -compared to the matrix material.Keywords: aluminium matrix composites, halloysite nanotubes, mechanical alloying, hot extrusion W pracy przedstawiono wybrane wyniki badań materiałów kompozytowych o osnowie stopu AlMg1SiCu wzmacnianych cząstkami haloizytowymi wytworzonymi z wykorzystaniem metod metalurgii proszków, w tym mechanicznej syntezy i wyciskania na gorąco. Otrzymane w procesie mechanicznej syntezy i wyciskania na gorąco materiały kompozytowe charakteryzują się strukturą równomiernie rozłożonych, rozdrobnionych cząstek fazy wzmacniającej w drobnoziarnistej osnowie stopu AlMg1SiCu, sprzyjającą osiąganiu wyższych wartości właściwości wytrzymałościowych w porównaniu do stopu wyjściowego. Wytworzone nanostrukturalne materiały kompozytowe wzmacniane nanorurkami haloizytowymi o udziale masowym 15% charakteryzują się -w porównaniu do materiału osnowy -ponad dwukrotnie większą mikrotwardością.