Sharif Digital Repository

A carboxylate gadolinium-based metal-organic framework (Gd-MOF) is an exceptional candidate for magnetic resonance imaging agents, but its low drug adsorption capacity hinders this MOF from being used as a theragnostic agent. In this work, the Gd-MOF was synthesized by a simple solvothermal method. Then, different activation situations, including various solvents over different time periods, were applied to enhance the specific surface area of the synthesized MOF. Different characterization analyses such as X-ray diffraction and Brunauer-Emmett-Teller along with experimental quercetin adsorption tests were done to study the crystalline and physical properties of various activated MOFs. In... 

Hybrid nanoparticle comprising of nanosilica (NS) and nanodiamond (ND), denoted by ND@NS, was synthesized by a two-step chemistry route and then incorporated into styrene-butadiene rubber (SBR) at low concentrations up to 5 phr by a two-roll mill. Physical hybrids of NS and ND, i.e., ND&NS, with a weight ratio similar to chemical hybrid (80:20 for NS:ND), were also incorporated into SBR. Field emission scanning electron microscopy observations revealed very fine dispersion of nanoparticles in the case of physical hybrids (ND&NS). In contrast, agglomerations and aggregation of nanoparticles were evidenced for ND@NS. Tensile and dynamic mechanical analyses exhibited a higher reinforcing effect... 

A series of ZIF-8/OND hybrid nanostructures with different percentages of oxidized nanodiamond (OND) was prepared. Then, the adsorptive removal performance of pristine ZIF-8 and its nanohybrids with OND towards methylene blue (MB) was investigated. The fabricated adsorbents were characterized via thermogravimetric analysis, X-ray diffraction, Fourier transform infrared spectroscopy, nitrogen adsorption/desorption, field emission scanning electron microscopy and zeta potential measurements. The maximal adsorption capacity of ZIF-8 (242 mg/g) was found to grow steadily with the increment in OND content and reached an approximate plateau at 343 mg/g for the nanohybrid containing 5 wt% OND, i.e.... 

Hydrogels with remarkable hydrophilicity and tunable toughness are appealing materials to serve as superabsorbent polymers. However, chemically cross-linked hydrogels often suffer from low toughness regardless of their considerable swelling, restricting their widespread applications. In comparison, the network of physically cross-linked hydrogels can be regulated to meet both a high swelling ratio and considerable toughness. Here, we develop superabsorbent and tough hydrophobic associated hydrogels using terpolymerization of poly acrylic acid (PAA), polyacrylamide (PAM), and lauryl methacrylate (LMA) within the micelles formed by sodium dodecyl sulfate (SDS) surfactant. To this end, various... 

This article deals with the adsorption performances of the unmodified nanodiamond (ND) and thermally oxidized nanodiamond (Ox-ND) for the removal of different heavy metal ions such as Fe (III), Cu (II), Cr (VI), and Cd (II) from wastewater. The adsorption capacities of the ions onto adsorbents are higher and follow the order: Ox-ND-3 > Ox-ND-1.5 > ND, which is consistent with their surface areas, zeta potentials, and the presence of carboxyl groups, suggesting that electrostatic attractions between the positive metal ions and the negatively charged adsorbents are the predominant adsorption mechanisms. Adsorption capacities of these adsorbents were found to be 26.8, 31.3, and 45.7 mg/g for Fe... 

A series of UiO-66/polyaniline (UiO-66/PANI) nanohybrids with various UiO-66 to aniline weight ratios ranging from 0.01 to 0.1 was synthesized using an in situ polymerization technique. The adsorption behavior of the neat PANI nanofiber network and the synthesized nanohybrids was examined toward anionic methyl orange (MO) dye from aqueous media. It was realized that the maximum adsorption capacity of PANI (229 mg/g) increases steadily by increasing the UiO-66 content in the nanohybrid up to 7 wt % at 426 mg/g, and then, it approximately levels off at 432 mg/g for the nanohybrid sample containing 10 wt % UiO-66, that is, UP10. Based on a thorough characterization, it was shown that UiO-66 is... 

Present work illustrated that the performance of ultrafine silica (Si) particles was improved considerably by rational hybridization with nanodiamond (ND). For this, Si@ND hybrid particles synthesized by chemical hybridization were incorporated into styrene-butadiene rubber (SBR) up to 10 phr. Scanning electron microscopy revealed coarse flower-like clusters for Si@ND nanohybrids, while Si exhibited rigid agglomerates in SBR. Comparing with physical hybrid (Si&ND) and single Si particles, it was revealed that chemical hybrids synergistically improved tensile properties, like 100% and 135% improvements in tensile strength and elongation at break, respectively. Dynamic mechanical analysis of... 

A series of nanohybrids using ZIF-8 in the presence of chitosan (CS) at various compositions (0.5–15 wt%) were synthesized. Thorough characterization exhibited that the morphology of the nanoparticles in terms of surface charge, particle size, specific surface area, and pore volume is significantly dominated by the CS content in the hybrid nanoparticles. Amongst the nanoparticles synthesized, a hybrid nanoparticle containing 2 wt% CS, named CS-ZIF-2, represented the largest positive zeta potential and smallest particle size. Moreover, adsorption experiments indicated that CS-ZIF-2 had considerable adsorption capacity against anionic dye (Congo Red, CR) compared with the individual ZIF-8 and... 

In the present research, the influence of nanodiamond (ND) and a physical hybrid of ND and fumed nano-SiO2 were investigated on the performance of a typical tire tread compound. The styrene-butadiene rubber (SBR) and cis-butadiene rubber (BR) blend filled with a commercial grade highly dispersive silica at 70 phr loading were used as typical tire tread compound. ND was substituted partially with silica at two different concentrations of 5 and 10phr. Meanwhile, 5 phr of ND/nano-SiO2 hybrids with the weight ratio of 2.5/2.5 and 1/4 were substituted with silica. ND-Filled compounds exhibit increased scorch and cure time compared to controls. Improvement in different characteristics of the... 

According to the great potential of zero-valent iron nanoparticle applications in the environmental, medical, chemical, packaging and many other industries, there is still a need to tailor their production methods. This study reports the production of a hybrid nanostructure based on iron nanoparticles (INPs) produced in/on montmorillonite (MMT) nanoclays as an oxygen scavenger and barrier additive in polymeric packaging materials of oxygen-sensitive products. INPs and MMT were demonstrated to have effective mutual interactions in which the MMT host played a chemophysical trapping role for iron particles, causing smaller particles around 10 nm with 6.2 g/m2 higher specific surface area by... 

In this study, nano-sized diamond particles (ND) were functionalized in two consecutive stages. First, dry thermal oxidation was employed to obtain carboxylated ND. In the next step, carboxylated ND was properly surface modified through wet chemistry to acquire aminated-ND (ND-NH2). Then, polyaniline (PANI) was synthesized in the presence of aminated-ND particles at a broad concentration from 1 wt% to 70 wt% to obtain PANI/ND hybrid nanostructures. The chemical structure, morphology, and thermal stability of nanoparticles were comprehensively characterized by different techniques such as FT-IR, UV–visible, TGA, XRD, FESEM, and TEM. It was observed that the morphology of PANI/ND... 

Over the past few years, development of wearable devices has gained increasing momentum. Notably, the demand for stretchable strain sensors has significantly increased due to many potential and emerging applications such as human motion monitoring, prosthetics, robotic systems, and touch panels. Recently, hydrogels have been developed to overcome the drawbacks of the elastomer-based wearable strain sensors, caused by insufficient biocompatibility, brittle mechanical properties, complicated fabrication process, as the hydrogels can provide a combination of various exciting properties such as intrinsic electrical conductivity, suitable mechanical properties, and biocompatibility. There are... 

Multifunctional magnetic shape memory polymer (SMP) nanocomposites with high sensitivity was synthesized through inclusion of silane functionalized nanodiamond@Fe3O4 (S-NDF) hybrid nanoparticle into polycaprolactone (PCL) based polyurethane acrylate (PUA) matrix followed by in situ crosslinking of the matrix. Highly biocompatible and superparamagnetic nanodiamond(ND)@Fe3O4 nanohybrids were synthesized through in situ co-precipitation method. The morphological analysis suggested that S-NDFs filled PUAs (2 to 9 wt% loadings) well interacted with both soft and hard domains of the matrix. The base polymer and the nanocomposites presented excellent shape fixity ratio (above 97%) and shape... 

In the context of nanodiamond/chitosan (ND/CS) nanocomposites and utilizing atomistic molecular dynamics, the interaction mechanism of adsorbed CS layer around a model ND has been investigated at three level of hydration: in bulk of water, water as a droplet, and completely dry condition. The effect of amination and carboxylation of ND has been studied. To ensure that the comparison of these model systems is meaningful (energetically and geometrically), the CS interphases around NDs were characterized through holistic concentration profiles and density distribution maps. Our results revealed that in a completely dry condition or hydrated by a molecularly small droplet, both of the... 

Reinforcement of rubbery materials with carbon nanotube (CNT) has gained much attention over the last few decades due to the inherent ability of CNT to improve the physical and mechanical properties of polymer composites. However, CNT renders electrical conductivity to the rubber composites, which could be problematic for a number of applications. In an attempt to overcome such issues, we controlled the insulating properties of styrene-butadiene rubber (SBR) nanocomposites by hybridization of CNT with nanodiamond (ND) particles without scarifying desirable features of the nanoparticles. In this respect, the effects of carbon nanotube (CNT) and nanodiamond (ND), either individually or in... 

In the present work, a series of nanohybrids based on UiO-66 as a physicochemical stable metal-organic framework (MOF) and different amounts of thermally oxidized nanodiamond (OND) (0.5–10 wt%) were synthesized and used as adsorbents for anionic (methyl red, MR, and methyl orange, MO) and cationic (malachite green, MG, and methylene blue, MB) dyes from contaminated water in single and binary dye solutions. The single adsorbents and their nanohybrids were characterized by FESEM, FTIR, XRD,TGA, BET, and zeta potential measurements. The experimental adsorption results displayed that the synthesized nanohybrids presented higher adsorption capacity for anionic dyes compared to cationic dyes in... 

In this research, UiO-66 and its composite nanoparticles with thermally oxidized nanodiamond (OND) were synthesized via a simple solvothermal method and utilized as solid adsorbent for the removal of anionic methyl red (MR) dye and cationic malachite green (MG) dye from contaminated water. The synthesized adsorbents were analyzed by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), thermogravimetric analysis (TGA), N2 adsorption–desorption, and zeta potential analyzer. The influences of various factors such as initial concentrations of the dyes, adsorption process time, solution pH, solution temperature and ionic... 

In this study, the effects of the type and content of reactive diluents on the permeation/separation of carbon dioxide/nitrogen (CO2/N2) through acrylate-terminated polyurethane (APU)-acrylate/acrylic diluent (APUA) composite membranes was investigated. A series of APUs based on poly(ethylene glycol) (PEG)-1000 g mol−1, toluene diisocyanate, and 2-hydroxyethyl methacrylate was synthesized and then diluted with several reactive diluents. The results obtained from differential scanning calorimetry (DSC) and Fourier transform infrared analyses showed that the microphase interference of hard and soft segments increased with increasing reactive diluent content. Furthermore, with increasing alkene... 

The multifunctional nanostructures with superparamagnetic and luminescent properties undergo revolution in the field of bio-nanotechnology. In this article, we reported a facile and efficient one-step modified co-precipitation method to load superparamagnetic Fe3O4 nanoparticle on oxidized nanodiamond (Ox-ND). Subsequently, the as-prepared Ox-ND/Fe3O4 hybrid nanoparticle was surface functionalized with vinyltrimethoxysilane (VTMS) to enhance its compatibility with organic media. The structure, morphology, magnetic, and optical properties of the nanohybrid were systematically investigated. The results confirmed successful loading of crystalline Fe3O4 on the surface of Ox-ND. Ox-ND/Fe3O4... 

In the present study, thermally oxidized nanodiamond (OND) was first modified non-covalently with dodecylamine (DDA) as corrosion inhibitor. In this respect, reactive primary amine of DDA molecule with high isoelectric point (IEP) could interact easily with negative charge carboxylic acid groups of OND. Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) proved that OND nanoparticle was successfully functionalized by DDA up to approximately 5 wt% grafting contnet. Both OND and dodecylamine modified OND (DND) were loaded in epoxy (EP)/polyamine hardener matrix at the same concentration of 1 wt% and applied on mild steel substrate. Morphology of EP-DND and...