Ternary layered double hydroxides (LDH) based on Cu- substituted Zn-Al for the design of efficient antibacterial ceramics

Abstract

Cu-substituted Zn-Al layered double hydroxides (LDH) were synthesized via co-precipitation method by varying the amount of Cu and explored as efficient antibacterial materials. The as-synthesized materials were characterized with various methods including elemental analysis, X-ray diffraction, transmission electron microscopy and scanning electron microscopy, particle size analyzer etc. which revealed that LDH materials were well crystallized. In addition, the flakes of LDH were well dispersed, one flake being easily distinguished from another. The as-synthesized Cu-LDH was calcined at a temperature range of 400-800 degrees C to get perfect spinel and corresponding oxide phase. Particle size analysis revealed that the size of the corresponding oxides decreases to nano size from micron size. As an application, antibacterial activity of the ternary LDH were investigated against both gram positive and gram negative bacteria. Furthermore, the antibacterial performance of corresponding spinels and oxides were compared with the as-synthesized materials and the result could prove the efficiency of spinel materials with that of LDH materials. The calcined composite was added with Portland cement in different ratios like 3:1, 1:1 and 1:3, 1:10, 1:15 and 1:20 and it was found that up to the ratio of 1:20, the mixture is an effective antibacterial material against E.coli. Therefore, Cu substitution in Zn-Al ternary LDH could be a straightforward approach for designing efficient antibacterial materials with various potential applications such as ceramics, cement add-ons etc.