We demonstrate the synthesis of benzimidazolones from o-phenylenediamines and CO₂ in the presence of gold nanoparticles supported on a composite material based on microcrystalline chitosan from shrimp shells and fibrous phosphosilicate.

The transmutation of waste into valuable materials has a special place in green chemistry. Herein, we report the preparation of quinazoline-2,4(1H,3H)-diones from 2-iodoaniline, isocyanides, and carbon dioxide in the presence of ZnO NPs stably placed on the surface of dendritic fibrous nanosilica by cellulose (DFNS/cellulose-ZnO) as a catalyst. This is a great economic strategy to create three bonds in a one-pot multicomponent reaction step employing functional groups. To prepare the catalyst, the dendritic fibrous nanosilica surface was first activated using cellulose as a substrate to support ZnO NPs. Cellulose acts as a stabilizing and reducing agent for the ZnO nanocatalyst and eliminates the need for a reducing agent. The structure of the prepared DFNS/cellulose-ZnO was examined by various methods, including thermogravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and inductively coupled plasma (ICP). The largest amount of quinazoline-2,4(1H,3H)-diones was obtained under ideal situations in the presence of 5 mg of DFNS/cellulose-ZnO under carbon dioxide (1 atm) utilizing a balloon set at 70 °C for 3 hours. The substance was reused for ten consecutive runs and the quinazoline-2,4(1H,3H)-dione content was more than 92% each time. This indicates the potential for application in the green and economic production of quinazoline-2,4(1H,3H)-diones, especially from low-cost feedstocks.

We studied the potential application of an efficient, reusable, and easily recoverable catalyst of dendritic fibrous nanosilica (DFNS)-supported platinum(ii) complexes (DFNS/Pt(ii) NPs) to form cyclic carbonates in the presence of epoxides by converting carbon dioxide.

In this paper, the effect of GO/Al₂O₃ and Al₂O₃ synthesized nanoparticles on the durability of concrete is studied. To this end, after the synthesis of nanoparticles and confirmation of nanoparticles fabrication by SEM and FT‐IR spectra, three concrete samples for each experiment related to each mix design were prepared and subjected to freeze‐thaw cycles, high temperature, and acidic environment. The results show that the samples containing GO/Al₂O₃ nanoparticles had the least weight loss in freeze‐thaw cycles as well as better resistance against acidic environment and the lowest apparent changes at high temperature compared to the samples containing nano‐Al₂O₃ and the samples without nanoparticles. The replacement of 2 wt.% of cement with GO/Al₂O₃ nanoparticles results in the highest increase in concrete durability. The presence of nanoparticles in the concrete microstructure and the validation of the results are investigated by FT‐IR, SEM, and EDX spectra.

Thymus, an aromatic plant of the family lamiaceae, has valuable medicinal properties commonly used in traditional and modern medicine across the world. This plant is mainly native to the northern temperate regions such as southern Europe and Asia. In Iran, several species of this plant grows in most of the temperate and mountainous areas. In this study, chemical compounds of flowering shoot of two types of thyme, namely Thymus vulgaris and Thymus kotschyanus, are compared. Thymus vulgaris was collected from the herbal plants farm of Science and Culture University of Kashmar, and Thymus kotschyanuswas collected from the heights of Bojnurd. Water and steam distillation methods were performed in order to collect the essential oils. Compounds of essential oils were identified using gas chromatography coupled with mass spectrometry GC-MASS. There were 10 common compounds identified: γ-terpinene, thymol, α-pinene, camphene, oleic acid,1-octen-3ol, trans-caryophyllene, β-myrcene, α-thujene, 1,8-cineole. Thymol was present in the essential oil and had the highest percentage, which was found to be at its highest in the flower bud of T. vulgaris at 54.66%. The antimicrobial properties of these plants were measured by the Disk diffusion method against two bacteria. It was discovered that T. vulgaris were found to have strong antimicrobial properties. The essential oils were more sensitive against Staphylococcus aureus than Pseudomonas aeruginosa.