Sharif Digital Repository

We introduce highly antifouling Polymer-Nanoparticle-Nanoparticle/Polymer (PNNP) hybrid membranes as multi-functional materials for versatile purification of wastewater. Nitrogen-rich polyethylenimine (PEI)-functionalized halloysite nanotube (HNT-SiO2-PEI) nanoparticles were developed and embedded in polyvinyl chloride (PVC) membranes for protein and dye filtration. Bulk and surface characteristics of the resulting HNT-SiO2-PEI nanocomposites were determined using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and thermogravimetric analysis (TGA). Moreover, microstructure and... 

Freeze desalination (FD) works upon the separation of impurities from pure water during ice crystals formation. The required cold source could be supplied by the cold energy of liquefied natural gas (LNG). In the current study, freeze desalination of seawater is explored by directly exploiting the cold energy of LNG within an appropriate range of temperature after producing work in a power generation cycle. A detailed discussion has been given on the inlet temperature of LNG to the FD unit for the first time. The direct utilization has the privilege of eliminating the addition of a secondary refrigerant and its refrigeration cycle to the FD process. A multi-objective optimization is... 

BACKGROUND: The clay treatment widely utilized to reduce unsaturated components in aromatic stream has a detrimental effect on catalyst lifetime. Due to the short lifetime of commercial clay, a huge number of studies have been carried out to address this problem over the last decade. This study aims to optimize the temperature for longer serviceability of clay by removal of unsaturated aliphatic components from aromatic streams through the adsorption and catalytic properties of clay. A novel process arrangement is introduced by scheduling the reuse of deactivated clay that is discarded after deactivation. RESULTS: Results showed that the suitable range of temperature for olefin removal is... 

The potential of carbon-based nanosheet membranes with functionalized pores is great as water treatment membranes. Using the molecular dynamic simulation technique, the dimethyl sulfoxide (DMSO) separation from the water/DMSO binary solution is investigated, and the functionalized graphene nanosheets are used as a membrane. This membrane was functionalized by –F (fluorine) and –H (hydrogen) functional groups. For the separation of DMSO, external hydrostatic pressures up to 100 MPa were applied to the considered systems. The separation mechanism was based on molecular size. Multiple analyses were done to study the capability of considered membranes for the separation of DMSO molecules from... 

We have developed an environmentally friendly benign and practical protocol for the highly diastereo and chemo selective synthesis of some novel derivatives of 6-amino-4-aryl-3-oxo-2,3,3a,4-tetrahydro-1H-pyrazolo[3,4-b]pyridine-5-carbonitrile via a one-pot three-component reaction between arylaldehydes, malononitrile and 3-amino-1H-pyrazol-5(4H)-one in the presence of acetic acid as a catalyst and aqueous green medium at the ambient temperature. In this synthetic protocol, we highlight the utility of enaminone functional groups of 3-amino-1H-pyrazol-5(4H)-one for the synthesis of N-cyclized pyrazolone fused 3,4-dihydropyridine skeletons. Some important features of this new synthetic green... 

Herbal medicine wastes (HMWs) are byproducts of medicine factories, which are mainly landfilled for their environmental problems. Only bearing in mind the contamination and concerns caused by the COVID-19 pandemic and environmental emissions, the worth of herbal medicine wastes management and conversion to green products can be understood. In this work, subcritical water treatment was carried out batch-wise in a stainless tube reactor in the pressure range of 0.792–30.0 MPa, varying the temperature (127–327 °C) and time (1–60 min) of extraction. This resulted in new and green material sources, including organic acids, amino acids, and sugars. Amazingly, at very low extraction times (below 5...