Tragacanth gum mediated green fabrication of mesoporous titania nanomaterials: Application in photocatalytic degradation of crystal violet.

Water remediation is a crucial subject in present century. Hence, several processes have been used for this aim, which the photodegradation method with high activity, cost-effectiveness, and durability has been remarkable. In this project, the various novel mesoporous Titania nanomaterials (MTN) were green synthesized using Tragacanth gum as coupling agent. The effect of calcination times on the crystalline structure of the resulted MTNs was examined. MTNs displayed the dramatically specific surface area with negative surface charge and nano-sheet structure, and they applied for photodegradation of crystal violet under ultraviolet irradiation due to proper band gaps energy. The obtained MTN in 8 h calcination time (MTN-8) showed the best photoreduction activity. Also, the superoxide radicals, electrons, and hole pairs represented the main degradation agents as the reduction rate of crystal violet. Next, the transformation pathways were proposed, which could be transformation singlet oxygen addition, hydroxyl addition, and N-demethylation reactions.

Investigation study of methyl violet photodegradation over alginate-carboxymethyl cellulose/titanium(IV) oxide/covalent organic frameworks bio-nanocomposite beads under ultraviolet irradiation.

Concerned about water treatment, it is of great importance to present new approaches for improving photocatalytic activity. Since photocatalysis is ubiquitous in almost all chemical manufacturing processes, the development of photocatalytic systems carries significance for our environment. In this regard, three different amounts of covalent organic frameworks decorated with titanium(IV) oxide nanoparticles (TiO2/COF hybrids) in Alginate-Carboxymethyl cellulose (Alg-CMC) blend matrix were prepared under ultrasound irradiation, which Citric acid and Calcium chloride acted as two green cross-linkages. Based on the physio-chemical analyses of these bio-nanocomposite (bio-NC) beads, the Alg-CMC blend polymer appeared to be the best candidate for a disparity of TiO2/COF hybrids. Not only did COF aid to increase the distribution of TiO2 nanoparticles, but it declined the bandgap energies. The resultant Alg-CMC/TiO2/COF (TiO2/COF = 15:6) bio-NC beads demonstrated efficient photodegradation activity towards Methyl violet (MV) under Ultraviolet light. The obtained results of scavenger studies indicated that superoxide radicals and electron agents played a major role in MV degradation. Further investigation confirmed that single oxygen addition and N-de-methylation could be two important pathways for the decomposition of MV by these bio-NC beads.

Fabrication of Polysulfone Beads Containing Covalent Organic Polymer as a Versatile Platform for Efficient Iodine Capture.

Radioactive iodine poses a significant risk to human health, particularly with regard to reproductive and metabolic functions. Designing and developing highly efficient adsorbent materials for radioactive substances remain a significant challenge. This study aimed to address this issue by the fabricating polymeric beads containing covalent organic polymer (COP) as an effective method for removing iodine vapor. To achieve this, a COP was first synthesized via the Friedel-Crafts reaction catalyzed by anhydrous aluminum chloride. Then, COP-loaded polysulfone (PSf) (COP@PSf) and PSf beads were prepared using a phase separation method. The beads produced in this research have exhibited remarkable proficiency in adsorbing iodine vapor, showing an adsorption capacity of up to 216 wt % within just 420 min, which is higher than that of most other similar beads reported in the literature.

Green fabrication of chitosan/tragacanth gum bionanocomposite films having TiO2@Ag hybrid for bioactivity and antibacterial applications.

Common materials used in tissue engineering are not cost-effective and natural origin. Hence, we designed green, safe, and antibacterial bionanocomposite (bio-NC) films based on polysaccharides, chitosan (CS) and gum tragacanth (GT) for the bone tissue engineering. For this aim, different percentages of titanium dioxide nanoparticles (TiO2 NPs) and green silver (Ag)-doped TiO2 NPs (TiO2@Ag hybrid) were employed as nanofiller to improve the properties of the CS-GT film. Moreover, the physicochemical characteristics of the bio-NC films were examined with a field-emission scanning electron microscope (FE-SEM), Fourier transform infrared, X-ray diffraction, and transmission electron microscopy (TEM). The FE-SEM images showed a rough surface for the CS-GT/TiO2@Ag bio-NC films, and TEM images showed better dispersion of TiO2@Ag hybrid than TiO2 NPs into the CS-GT matrix. Also, these bio-NC films were considered for the bioactivity test and the results showed formation of hydroxyapatite on the surface of the prepared bio-NC films. Furthermore, addition of GT led to an increase in the bioactivity of the CS-GT blend. Finally, antibacterial behavior of the prepared bio-NC films was investigated against Escherichia coli and Staphylococcus aureus bacteria with/without ultraviolet irradiation and the results indicated better antibacterial performance for the CS-GT/TiO2@Ag bio-NC film (TiO2:Ag = 1:1) under both conditions.