Incorporation of Silver Ions into Zirconium Titanium Phosphate: A Novel Approach toward Antibacterial Activity

The effects of nano-silver loaded zirconium phosphate on antibacterial properties, mechanical properties and biosafety of room temperature curing PMMA materials

Polymethyl methacrylate (PMMA) frequently features in dental restorative materials due to its favorable properties. However, its surface exhibits a propensity for bacterial colonization, and the material can fracture under masticatory pressure. This study incorporated commercially available RHA-1F-II nano-silver loaded zirconium phosphate (Ag-ZrP) into room-temperature cured PMMA at varying mass fractions. Various methods were employed to characterize Ag-ZrP. Subsequently, an examination of the effects of Ag-ZrP on the antimicrobial properties, biosafety, and mechanical properties of PMMA materials was conducted. The results indicated that the antibacterial rate against Streptococcus mutans was enhanced at Ag-ZrP additions of 0%wt, 0.5%wt, 1.0%wt, 1.5%wt, 2.0%wt, 2.5%wt, and 3.0%wt, achieving respective rates of 53.53%, 67.08%, 83.23%, 93.38%, 95.85%, and 98.00%. Similarly, the antibacterial rate against Escherichia coli registered at 31.62%, 50.14%, 64.00%, 75.09%, 86.30%, 92.98%. When Ag-ZrP was introduced at amounts ranging from 1.0% to 1.5%, PMMA materials exhibited peak mechanical properties. However, mechanical strength diminished beyond additions of 2.5%wt to 3.0%wt, relative to the 0%wt group, while PMMA demonstrated no notable cytotoxicity below a 3.0%wt dosage. Thus, it is inferred that optimal antimicrobial and mechanical properties of PMMA materials are achieved with nano-Ag-ZrP (RHA-1F-II) additions of 1.5%wt to 2.0%wt, without eliciting cytotoxicity.

Thermal plasma processing of Moringa oleifera biochars: adsorbents for fluoride removal from water

Anthropogenic activities accelerate fluoride contamination in groundwater, which largely affects public health. Though biochars have been explored for defluoridation, the plasma technology-based production of biochars has not received as considerable attention as other methods and it is also important that biochars be tested on groundwater samples. In the present study, for the first time, we report the preparation of biochars from different parts of Moringa oleifera using thermal plasma processing and demonstrate fluoride adsorption in both synthetic and contaminated groundwater. Water samples were collected from different locations in Nuapada district of Odisha such as Kotamal-Makardampada (20°24'46''N 82°37'19''E), Pandrapathar (20°34'41''N 82°39'25''E), Karlakot-Kadobhata (20°22'52''N 82°37'24''E), Kotamal-Jhakarpada (20°24'35''N 82°37'20''E), and Dohelpada (20°33'50''N 82°38'57''E). The Moringa leaf samples are processed at 1600 °C for 3 min in an inert atmosphere under a continuous flow of argon to get suitable biochars. The plasma-synthesized biochars contain larger exposed surfaces, which are efficient for the adsorption of fluoride. The prepared biochars were highly porous, amorphous, and contain > 72% carbon, which increases the efficiency of defluoridation due to the surface adsorbate site exposed. XRD of the samples showed the presence of calcium hydroxide, magnesium oxide, and calcium oxide, and large peaks of carbon. Raman data showed the double bond of carbon with oxygen in the form of carbonyl bonds, thioether, and sulfhydryl bonds, which contribute to the protonated site for the adsorption of fluoride, and assist in water penetration and swelling of biochars. The biochar of Moringa oleifera is very efficient for the adsorption of fluoride from standard samples as well as groundwater samples up to a concentration of 6 ppm. Conclusively, the present investigation shows that Moringa oleifera leaves are a good alternative adsorbent that could be used for the removal of fluoride from groundwater samples with > 85% removal in 18 h using 1 g biochar for 100 mL or 10 g biochar for 1 L water containing 4 ppm fluoride. To our knowledge, this is the first report on the thermal plasma-based production of Moringa biochars for the removal of fluoride from drinking water.

Adsorption of Ag (I) Ions at the Zirconium Phosphate/KNO3 Aqueous Solution Interface

The paper presented the mechanical (MChT), microwave (MWT), and hydrothermal (HTT) methods of zirconium phosphate samples modification in order to improve its adsorption affinity for the Ag (I) ions. The FTIR studies proved that the modification of both gel and xerogel samples with the ultrasonic microwaves causes an increase in the concentration of phosphate groups on the surface of MWT-modified zirconium phosphate: the isoelectric point pHiep = 2.2–2.9 for these samples against 3.9 for the initial sample and pKa2 values were 4.7–5.6 and 6.3, respectively. As resulting from the Ag⁺ ion adsorption studies, the MWT treatment of zirconium phosphate samples caused the greatest affinity of Ag⁺ ions for the surface of MWT zirconium phosphate. Compared with the initial ZrP sample, the shift of the Ag (I) ion adsorption edge towards lower pH values was observed, e.g., with adsorption of Ag (I) ions from the solution with the initial concentration of 1 µmol/dm³ for the initial ZrP sample pH50% = 3.2, while for the sample MWT ZrPxero pH50% = 2.6.

Synthesis of cationic acrylate copolyvidone-iodine nanoparticles with double active centers and their antibacterial application

Antibacterial materials are rapidly emerging as a primary component in the mitigation of bacterial pathogens, and functional polymers play a vital role in the preparation of antibacterial coatings. In this study, a novel antibacterial polymer with double active centers was synthesized. Firstly, using one-pot soap-free emulsion polymerization technology, the cationic acrylate copolymeric polyvidone (CACPV) was synthesized by copolymerization of four monomers with different functions, which were methyl methacrylate (MMA), N-vinyl-2-pyrrolidone (NVP), γ-methacryloxypropyltrimethoxysilane (MAPTS) and [3-(methacryloylamino)propyl]trimethylammonium chloride (MAPTAC). Secondly, using iodine complexation, the cationic acrylate copolyvidone-iodine (CACPVI) nanoparticles were prepared. After being characterized by scanning electron microscopy (SEM), dynamic light scattering (DLS), X-ray photoelectron spectroscopy (XPS) and contact angle test, the antibacterial activity of CACPVI was evaluated against the typical human pathogens Escherichia coli (E. coli, Gram-negative) and Staphylococcus aureus (S. aureus, Gram-positive). Additionally, CACPVI was used to improve the antibacterial activities of some materials, such as ink, dye and coatings. It was found that CACPVI presented an excellent antibacterial synergy. When the antibacterial activities were more than 99% at a concentration of 40.00 μg mL-1, CACPVI exhibited long-term antibacterial performance as expected. The antibacterial mechanism of this synergy was also investigated. In summary, a novel antibacterial polymer material with double active centers was successfully synthesized and was widely applied in coating, dye and ink materials for minimizing bacterial infection.

Recent Advances in Metal Decorated Nanomaterials and Their Various Biological Applications: A Review

Nanoparticles (nanoparticles) have received much attention in biological application because of their unique physicochemical properties. The metal- and metal oxide-supported nanomaterials have shown significant therapeutic effect in medical science. The mechanisms related to the interaction of nanoparticles with animal and plant cells can be used to establish its significant role and to improve their activity in health and medical applications. Various attempts have been made to discuss the antibiotic resistance and antimicrobial activity of metal-supported nanoparticles. Despite all these developments, there is still a need to investigate their performance to overcome modern challenges. In this regard, the present review examines the role of various types of metal-supported nanomaterials in different areas such as antibacterial, antifungal, anticancer, and so on. Based on the significant ongoing research and applications, it is expected that metal-supported nanomaterials play an outstanding role not only in medical but also in other important areas.

Supercritical synthesis of layered elongated hexagonal titanium phosphate nanoplates

Elongated hexagonal α-titanium phosphate nanoplates with single-crystalline and controllable structures were synthesized in supercritical ethanol without any template.

Improved supercapacitor potential and antibacterial activity of bimetallic CNFs–Sn–ZrO2 nanofibers: fabrication and characterization

The objective of our study was to develop a new class of one-dimensional Sn–ZrO₂ nanocrystal decorated CNFs.