Conclusion

Barium sulphate, a chemical compound with the formula BaSO₄, is widely recognized for its numerous applications in various industries, particularly in the field of medicine, paints, plastics, and as a component in drilling fluids. One of the distinguishing features of barium sulphate is its striking physical property its color. Understanding the color of barium sulphate not only helps in identifying the compound during handling but also plays a significant role in its applications and quality assessment.

It should also be considered that due to the low pH in the stomach, the increased dissolution of the TiO₂ particles may increase its bioavailability and may facilitate the entry of titanium ions into the blood circulation. Despite the relatively large consumption of TiO₂ as a food additive, no studies on the effect of pH on its absorption and bioavailability have been found in the literature. This can be attributed to a general belief that TiO₂is completely insoluble. However, this is not completely true, as TiO₂ particles show a certain degree of solubility.

The vitaminC@P25TiO₂NPs, on the other hand, were obtained through an optimized method based on Mallakpour et al. [27]. Initially, 0.02 g of P25TiO₂NPs were dispersed in 1 mL of ultrapure water and stirred in a Vortex. Next, 100 μL of HCl (0.01 M) were added (pH 2) to 100 uL of P25TiO₂NPs to avoid gel formation. Then, 100 μL of vitamin C dissolved in ultra-pure water (5.0 × 10⁻³ M) solution were added to the mixture and was ultrasonicated for 30 min. Finally, vitamin C was added in excess to gain a beige-orange color suspension, and the ultrasonication continued for another 30 min. The pellet obtained after centrifuging the suspension for 10 min at 4500 rpm was resuspended in ultrapure water, centrifuged again, and then lyophilized.