Effectiveness of plant-mediated synthesis of hydroxyapatite nano-particles impregnated in Pistachio oleogum resin on mineral contents of human teeth. An in-situ single-blind controlled study.

OBJECTIVES: This study aimed to synthesize and characterize an environmentally friendly nanohydroxyapatite (n-HA) and evaluate its impact on enamel mineral content when incorporated into a Pistachio oleo gum resin (Saqqez) bio-chewing gum for in-situ models. We compared the effects of this green nano-hydroxyapatite (G n-HA) with those of a commercially available synthetic nano-hydroxyapatite (S n-HA). METHODS: Various analytical techniques were employed including XRD, FESEM, FT-IR, EDX/SEM and TGA/DTA to characterize the crystallinity, size and composition of the G n-HA powder. Three chewing gum groups were formulated: (1) Saqqez gum containing 10% wt G n-HA, (2) Saqqez gum containing 10% wt S n-HA, and (3) pure Saqqez gum. In order to evaluate the impact of these chewing gums on enamel, intraoral appliances were fabricated, each containing six enamel specimens. Participants were instructed to chew the gums while wearing these appliances. The calcium (Ca+2) and phosphorus (P) levels in enamel specimens, both with and without exposure to an acid challenge, were quantified using EDX/SEM. FE-SEM was employed to capture the microstructure of the enamel surface. In terms of the statistical analysis, one-way ANOVA and Tukey's post hoc tests were utilized to compare the data, where the significance level (α) was set at 0.05. RESULTS: The characterization tests confirmed the successful synthesis of G n-HA. Furthermore, EDX/SEM analysis of the enamel specimens from the intraoral appliance revealed significant variations in calcium (Ca+2) content among the enamel specimens (P = 0.000). The S n-HA group, in particular, exhibited the highest Ca+2 content, while the pure Saqqez group displayed the lowest. Nonetheless, there was no statistically significant differences in phosphorus (P) content observed among the three groups (P = 0.27). CONCLUSIONS: Saqqez gum can be considered a wholesome natural chewing gum that serves, as a carrier for delivering remineralization agents to the tooth surfaces. This was evident in the groups containing n-HA, exhibiting elevated Ca+2 levels. It's noteworthy that G n-HA demonstrated less efficacy in enamel remineralization compared to S n-HA.

Enhanced visible-light-driven photocatalytic performance for degradation of organic contaminants using PbWO4 nanostructure fabricated by a new, simple and green sonochemical approach.

Water contamination has turned into a critical global concern that menaces the entire biosphere and has a notable effect on the lives of living beings and humans. As a proper and environmentally friendly solution, visible-light photocatalysis technology has been offered for water contamination removal. There is a strong interest in the design of the efficient catalytic materials that are photoactive with the aid of visible light. Herein, to fabricate a highly efficient photocatalyst for removal of organic pollution in water, a facile and swift sonochemical route employed for creation of the spindle shaped PbWO4 nanostructure with the aid of an environmentally friendly capping agent (maltose) for the first time. To optimize the efficiency, dimension and structure of lead tungstate, various effective factors such as time, dose of precursors, power of ultrasound waves and kind of capping agents were altered. The attributes of PbWO4 samples were examined with the aid of diverse identification techniques. The produced lead tungstate samples in role of visible-light photocatalyst were applied to remove organic pollution in water. The kinds of pollutants, dose and type of catalyst were examined as notable factors in the capability to eliminate contaminants. Very favorable catalytic yield and durability were demonstrated by spindle-shaped PbWO4 nanostructure (produced at power of 60 W for 10 min and with usage of maltose). Usage of ultrasonic irradiation could bring to improvement of catalytic yield of PbWO4 to 93%. Overall, the outcomes could introduce the spindle-shaped PbWO4 nanostructure as an efficient substance for eliminating water contamination under visible light.

Green sol-gel auto combustion synthesis and characterization of double perovskite Tb2ZnMnO6 nanoparticles and a brief study of photocatalytic activity.

In this work, new double perovskite Tb2ZnMnO6 nanoparticles were successfully synthesized by a sol-gel auto combustion method. To synthesize these nanoparticles, three known sugars, lactose, fructose, and maltose, and liquorice powder, which contains quantities of sugar and other organic compounds, were used as fuel. Images obtained from Scanning Electron Microscopy (SEM) analysis implied that maltose-based nanoparticles are homogenous and less in particle size. Further, different maltose ratios were applied to get the best size and morphology. The optimum sample was used to continue the other analysis to check other features of the nanoparticles. Also, the optimum sample was used for the removal of dye contamination under the photocatalytic process. Photocatalytic tests were performed in neutral and alkaline pH conditions under UV-light irradiation. It has been found that the decolorization percent for methyl orange was about 35% and for methyl violet about 55% at neutral pH. Also, this value for methyl violet was about 90% at pH = 8. The results obtained from the study of photocatalytic properties introduce these nanoparticles as a desirable option for removing dye contaminants from aqueous media.

Sol-gel auto combustion synthesis, characterization, and application of Tb2FeMnO6 nanostructures as an effective photocatalyst for the discoloration of organic dye contaminants in wastewater.

In this study, the auto-combustion sol-gel method was used to prepare novel Tb2FeMnO6 (TFMO) double perovskite nanoparticles. Chemical and natural fuels were used to achieve these particles with appropriate size. The resulting particles were examined via X-ray powder diffraction (XRD) and scanning electron microscopy (SEM) techniques. Rietveld analysis was also performed to confirm the crystallinity and lattice parameters of the formed particles. The particles obtained in the presence of maleic acid were selected as the optimal sample (S4), and the particles obtained in the presence of pomegranate paste were chosen as the non-optimal sample (S8) in terms of size and morphology. Both particles were used to investigate the photocatalytic activity. Fourier transform infrared spectroscopy (FTIR), UV-Vis diffuse reflectance spectroscopy (DRS), and vibrating sample magnetometer (VSM) analyses and N2 adsorption/desorption isotherms were performed for both samples and the results were compared. Erythrosine and malachite green dyes in aqueous solutions were used as contaminants in the photocatalysis process. The results showed 22% and 20% discoloration for S4 and 41% and 30% discoloration for S8 in the presence of erythrosine and malachite green under visible light irradiation. The photocatalytic activity was investigated under UV light for S4, which showed 80% and 50% discoloration for erythrosine and malachite green, respectively. Investigating the photocatalytic activity of TFMO double perovskite nanoparticles showed that these nanoparticles could be a desirable option for mitigating water pollution.

DyMnO3/Fe2O3 nanocomposites: simple sol-gel auto-combustion technique and photocatalytic performance for water treatment.

Recently, nanocomposite photocatalysts based on semiconductors have drawn consideration due to their suitable bandgap. Combination of tow of several semiconductors can slow down the electron-hole recombination. For this purpose, we have introduced DyMnO3/Fe2O3 nanocomposite as a novel and efficient catalyst for water purification. For this regard, DyMnO3/Fe2O3 nanocomposite has been fabricated by a simple and green sol-gel auto-combustion technique. The impact of calcination temperature, time, and types of fuel was investigated on morphology, structure, and purity of the products. The samples were identified by XRD, FTIR, FESEM, HRTEM, BET, and DRS. The bandgap was calculated by DRS to be 3.20 and 3.28 eV for Fe2O3 and DyMnO3. Due to the appropriate bandgap, DyMnO3/Fe2O3 degraded 80% of methylene blue under UV light. The future aspects of the DyMnO3/Fe2O3 application can be applied in thermoelectric materials, solid fuel cells, electrochemical gas sensors, and electrochemical biosensors.

Sonochemical-assisted synthesis of pure Dy2ZnMnO6 nanoparticles as a novel double perovskite and study of photocatalytic performance for wastewater treatment.

Herein, successful synthesis of pure Dy2ZnMnO6 nanoparticles as a new double perovskite was reported. The samples were prepared using various base and surfactants under ultrasound waves (30 W and 20 kHz). The effects of base type and surfactant type as effective parameters on morphology and size of products and the roles of calcination temperature and sonication as operative procedures on purity of products were investigated. According to the results tepa was chosen as favorite base to produce the smallest particles with the most homogeneity and T ≥ 900 °C was considered as desirable calcination temperature for synthesis of pure product. It seemed that high temperature of ultrasound waves can decrease the required calcination temperature, so facilitates the achievement of pure product. Moreover, photocatalytic performance of the prepared product was examined by decolorization of three dyes including Eriochrome Black T, Methyl orange and Methyl violet under UV irradiation. The most and the least percent of degradation were assigned to Methyl violet (90.44%) and Methyl orange (48.39%), respectively. Paramagnetic property of this product was considered as the other advantage for its photocatalytic performance because of it can be easily separated by magnetic field and recycles again.