Vol. 2 No. 1 (2024): March

Titanium is widely recognized as the most biocompatible metal due to the inert passive oxide layer that forms spontaneously on its surface. However, dental implants made of titanium and its alloys remain susceptible to corrosion when exposed to saliva for extended periods in the oral environment. Additionally, the presence of alloying elements in the alloy may raise concerns about potential toxicity concerns upon release into the human body. Consequently, there is an increasing need for research aimed at improving the mechanical properties and biocompatibility of dental implants made from both commercially pure titanium (CP Ti) and Ti alloys. This article provides a review of recent publications that investigate the impact of grain size reduction on ultrafine-grained and nanocrystalline CP Ti and Ti alloys. The article explores the modification of the oxide layer to nanotube TiO₂ and its influence on corrosion resistance. The analysis of accumulated data provides a comprehensive understanding of the mechanisms underlying corrosion resistance improvement, offering valuable insights into the crucial directions for future research in this field.

This study investigates the selective adsorption capabilities of Ni/Al Layered Double Hydroxide (LDH) modified with Eucheuma cottonii for the removal of cationic and anionic dyes from aqueous solutions. The primary objective was to evaluate the efficiency and selectivity of these modified adsorbents towards different dyes, including rhodamine-b, malachite green, methylene blue (cationic dyes), and direct yellow, methyl orange, direct green (anionic dyes). The modification process aimed to enhance the adsorption properties of LDHs, leveraging the natural adsorption capabilities of Eucheuma cottonii. Experimental results demonstrated significant differences in adsorption percentages among the tested dyes, with malachite green showing the highest adsorption efficiency among cationic dyes, indicating a strong affinity of the modified adsorbents towards cationic dyes. However, the ability to also adsorb anionic dyes suggests the dual-functionality of the modified LDHs, making them versatile agents for dye removal in water treatment applications.

This experimental inquiry delves into the evaluation of compressive and flexural strengths in concrete through the utilization of waste glass powder as a partial substitute for cement. Compressive strength is a key metric, indicating the concrete’s ability to effectively support structural axial loads, while flexural strength signifies its capacity to withstand deformation under bending, specifically the maximum tensile stress it can endure without fracturing when subjected to a bending moment. Certain pozzolanic materials have demonstrated the ability to enhance the mechanical strength of concrete when used as a cement replacement, and waste glass powder is among them. To address this, the experimental investigation included the substitution of cement with glass powder at different proportions (0%, 10%, 15%, 17.5%, and 20%) in both cubic and prismatic samples. Compressive strength and flexural strength tests were made following the curing of the samples for 7, 14, and 28 days. The findings indicated that the 17.5% cement replacement level exhibited a 6.07% over-strength for compressive strength and a 6.85% over-strength for flexural strength on the 28^th day. However, the 15% replacement showed superior strength compared to a 10% replacement, and the 10% replacement was stronger than a 0% cement replacement. Notably, the 20% cement replacement displayed negative over-strength percentages, specifically -2.42% in compressive strength and -1.42% in flexural strength on the 28^th day. This deviation raises concerns about its suitability for use in concrete applications, signifying that a 20% replacement may not be recommended.

The selectivity analysis of anionic dye adsorption by E. cottonii macroalgae has been successfully conducted in this study. Selectivity analysis encompassed congo red, direct yellow, methyl orange, and direct green dyes with measurements taken at 0, 2, 4, 6, 8, and 10-minute intervals. The dye concentration was standardized at 50 g/mL, and 20 mL of each dye solution was utilized. Variations in absorbance were assessed using a UV-Vis Spectrophotometer, revealing that E. cottonii exhibited the highest selectivity for methyl orange. Characterization through FT-IR indicated the presence of O-H, C-H aliphatic, C=N, C=C, C-O, and N-H bonds in the dried E. cottonii macroalgae material. These results affirm the superior selectivity of E. cottonii in adsorbing methyl orange, as demonstrated by the selectivity test.

In this study, the synthesis of composite materials produced from Ni/Al with three types of carbon-based materials namely chitosan (Ch), cellulose (Ce), and graphene oxide (GO) was successfully carried out supported by X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), and Brunauer-Emmett-Teller (BET) analysis. The combined characteristics of the two starting materials are present in the composite material based on XRD and FT-IR data. The surface area of Ni/Al-LDH increased after compositing with Ch, Ce, and GO, from 3.3 m²/g to 9.5 m²/g in Ni/Al-Ch, 5.1 m²/g in Ni/Al-Ce, and 78.4 m²/g in Ni/Al-GO. These findings indicate that the materials are suitable for various applications such as photocatalytic and adsorption as effective materials in further research.