Characterization of the antibacterial galactomannan/ $$\hbox {Zn(OH)}_{2}$$ Zn(OH) 2 –ZnO composite material prepared in situ from a green process using mesquite seeds as a biopolymer source

Abstract

In this work, the preparation of an antibacterial galactomannan/Zn(OH) 2-ZnO composite material by a green process is proposed and demonstrated. The galactomannan polysaccharide was extracted from the arid-native mesquite (Prosopis spp.) seeds through a hydrothermal technique, and it was used as an organic polymeric matrix for the in situ chemical precipitation of the Zn(OH) 2-ZnO inorganic particles from simple reactions between Zn 2+ and NaOH. The preparation was performed under standard conditions in aqueous solutions. The composite material, which was obtained by centrifugation of the previous preparation, was characterized by X-ray diffraction, transmission and scanning electron microscopy, infrared spectroscopy and thermal analysis. By means of these techniques, it was deduced that the composite material is highly crystalline (about 94%), composed of about 92% inorganic and 8% organic portion, and has a predominant size of 760 nm and a mean size of 800 nm. The antibacterial activity of the composite material was also studied, which resulted better against Escherichia coli (Gram-negative bacterium) than against Staphylococcus aureus (Gram-positive bacterium), which was calculated in a difference of about 30%. This work presents the high potential of galactomannans to form functional composite materials with inorganic particles.

Chemical Solution Deposition of Al(OH)3‐AlOOH Films: Application for Surface Sensitizing of Rigid and Flexible Substrates to Improve the Adhesion in Coating Technology Areas

“…Given the above, and given our previous experience, we decided to use aluminum oxide (Al 2 O 3 ) material deposited by radio‐frequency sputtering [24] to test the effects of adhesion. However, our recent line of research is oriented to the utilization of non‐vacuum techniques, and to better employ equipment, tools, and reagents that are available in most research laboratories, and to follow methodologies that can be carried out under typical lab conditions [21,22,25‐31] . In this sense, in the present work, we present a simple and practical formulation to obtain adherent and homogeneous thin films of an aluminum compound (in fact, a mixture of aluminum hydroxide, Al(OH) 3 , and aluminum oxyhydroxide, AlOOH, as will be demonstrated latter) by chemical solution deposition, which is a “wet” technique that is well known for its simplicity, versatility, reproducibility, low cost, large‐scale and industry compatibility, among many others advantages over physical techniques [15] .…”

“…However, our recent line of research is oriented to the utilization of non-vacuum techniques, and to better employ equipment, tools, and reagents that are available in most research laboratories, and to follow methodologies that can be carried out under typical lab conditions. [21,22,[25][26][27][28][29][30][31] In this sense, in the present work, we present a simple and practical formulation to obtain adherent and homogeneous thin films of an aluminum compound (in fact, a mixture of aluminum hydroxide, Al(OH) 3 , and aluminum oxyhydroxide, AlOOH, as will be demonstrated latter) by chemical solution deposition, which is a "wet" technique that is well known for its simplicity, versatility, reproducibility, low cost, large-scale and industry compatibility, among many others advantages over physical techniques. [15] Perhaps this is the main contribution of the present research, since there are only three works that deal with aqueous formulations to deposit thin films of aluminum Images at the left correspond to the appearance of the samples at the moment that are withdrawn from the reaction solutions, while the right images correspond to the samples after the cleaning process with water and wet cotton.…”

One-Step Synthesis of ZnO Films by Chemical Bath Deposition Not Using Thermal Annealing

“…It has a reported wurtzite-like structure 7 , with an exciton binding energy of 60 meV 8 , and a whole effective mass of 59 meV 8 . Because of this, there are studies of ZnO for application in medicine, electronics, among other fields [9][10][11][12][13] . Its high conductivity and optical transmittance identify it as promising for active layers in thin film transistors 14 .…”

Effect of Extraction Method in the Content of Phytoestrogens and Main Phenolics in Mesquite Pod Extracts (Prosopis Sp.).

“…Mesquite is a legume of genus Prosopis native of Central Mexico. Mesquite comes from Nahuatl (the language spoken by the Aztecs) "mizquitl" (Bouttier-Figueroa et al, 2017), it is abundant in Central and Northern Mexico as well as in Baja California Peninsula (Sauceda et al, 2014). It also grows in Texas, California, Utah and Kansas, as well as in Argentina, Chile, Brazil and Bolivia.…”