Sharif Digital Repository

Fullerene derivatives with a strong electron-accepting ability play a crucial role in enhancing both the performance and stability of perovskite solar cells (PSCs). However, most of the used fullerene molecules are based on [6,6]-phenyl-C61-butyric acid methyl ester (PCBM), which limits the device performance due to difficulties in preparing high-quality and uniform thin films. Herein, solution-processable azahomofullerene (AHF) derivatives (abbreviated as AHF-1 and AHF-2) are reported as novel and effective electron-transport layers (ETLs) in p-i-n planar PSCs. Compared to the control PCBM ETL-based PSCs, the devices based on AHFs exhibit higher photovoltaic performances, which is... 

Titanium dioxide (TiO2) is an extensively used electron transporting layer (ETL) in n–i–p perovskite solar cells (PSCs). Although, TiO2 ETL experiences the high surface defect together with low electron extraction ability, which causes severe energy loss and poor stability in the PSC. In this study, a new intermediate layer consisting of gold nanoparticles functionalized with fully conjugated fullerene C60 derivative (C60-BCT@Au NPs) that enhances the interfacial contact at ETL/perovskite interface leading to a perovskite film with improved crystallinity and morphology is reported. Moreover, the studies demonstrate that the interface modification of the TiO2 ETL with C60-BCT@Au NPs... 

In the present study, a model was proposed to determine the elastic properties of the family of fullerenes at different temperatures (between 300 and 2000 K) using a combination of molecular dynamics simulation and continuum shell theory. The fullerenes molecules examined here are eight spherical fullerenes, including C60, C80, C180, C240, C260, C320, C500, and C720. First, the breathing mode frequency and the radius of gyration of the molecules were obtained at different temperatures by molecular dynamics simulations using AIREBO potential. Then, these data were used in a continuum model to obtain the elastic coefficients of these closed clusters of carbon in terms of temperature changes.... 

Molecular machines and surface rolling molecules show great potential to accomplish different tasks in several fields, such as bottom-up assembly and nanomanipulation. Many researchers have investigated molecular machines, most of which was on a flat single-crystal substrate. In this paper, we studied the influence of vacancies in different sizes on the motion of a nanocar, a nanotruck, and C60 on a gold substrate at different temperatures by employing classical all-atom molecular dynamics. At the temperature of 200 K, a hole or vacancy appears as a repellent obstacle in the path of C60, and at higher temperatures, C60 can enter this hole. Although C60 has enough energy to escape single-atom... 

Background & Objective: The potent antioxidant property of fullerene C60 nanoparticles and their derivatives has been demonstrated in a wide range of in vitro and in vivo studies. Hence, we examined the effects of fullerene C60 on the oxidative stress parameters in brain and liver of the rats in normal situation. Materials & Methods: The study was performed in two groups of Wistar rats (each group, n = 6); normal and fullerene-treated normal animals. Treated rats received fullerene via oral gavage at dose of 1 mg/kg/day for 60 days. At termination of the study, the oxidative stress parameters were determined in brain and liver tissues, including the contents of glutathione (GSH) and... 

Removal of aromatic compounds from fuel is an essential requirement in new environmental policies. In the present study, poly(vinyl alcohol)/graphene oxide (GO) mixed matrix membranes were prepared and applied to the separation of toluene from iso-octane by pervaporation, considering the similarity and interaction between graphene and aromatics. The effects of crosslinking and GO content on separation efficiency have been investigated in detail. Owing to the high affinity of GO with toluene through s and π bonds, the selectivity of the membranes was increased by incorporating a low amount of GO. The results also indicated that noncrosslinked membranes have higher selectivity and permeation... 

The rotational and translational motions of nanocars and nanotrucks as well as their motion regimes at different temperatures are investigated. In recent years, few similar types of molecular machines have been simulated. In contrast to previous studies, which have used the Rigid-Body Molecular Dynamics (RBMD) method, an all-atom model and classic atomistic dynamics have been employed in this paper to achieve better accuracy. Our results demonstrated that the exibility of the chassis and its attachment to the gold surface played an important role in the motion of a nanocar. In fact, a heavier and more exible nanocar chassis reduces its speed compared to a nanotruck. In addition, the results... 

Two new macrocyclic ligands containing 17- and 19-membered O2N3-donor aza-crowns anchored to [60]Fullerene were synthesized and characterized by employing HPLC, electrospray ionization mass (ESI-MS), 1H and 13C NMR, UV–vis, IR spectroscopies, as well as powder X-ray diffraction (PXRD) and thermogravimetric analysis (TGA) in solid state. TGA measurements revealed that upon linking each of these macrocycle rings to [60]Fullerene, the decomposition point measured for [60]Fullerene moiety was increased, indicating on the promoted stability of [60]Fullerene backbone during binding to these macrocyclic ligands. Moreover, the ground state non-covalent interactions of [60]Fullerene derivatives of... 

Two mononuclear coordination complexes of fullerene[60] with Pd(dba)2 (dba = dibenzylideneacetone), [(η2-C60)Pd(Ph2P(CH2)2PPh2C(H)C(O)R)2] (R = C10H7 (1), C6H4Cl (2)), have been prepared using a simple procedure to explore new directions in palladium catalysis and nanocarbon chemistry. The palladium(0)-[60]fullerene complexes incorporating unsymmetrical phosphorus ylides have been characterized by 1H, 13C and 31P NMR spectroscopic methods and other conventional techniques such as IR, TGA, SEM, ICP-OES, EDX and TEM analysis. Attributed to the enhanced dispersity and uniform size of the Pd nanoparticles with phosphine-functionalized fullerenes, the prepared catalysts exhibited comparable... 

The present paper reports the spectroscopic investigations on the complexation of Cu(II) with two macrocyclic ligands bonded to [60]Fullerene (L1 and L2) measured in N-methylpyrrolidone (NMP) as solvent. On the basis of UV–vis-NIR spectroscopy applying Jobs method of continuous variation, typical 1:1 stoichiometries were established for the complexes of Cu(II) with L1, and L2. DFT calculations suggested that superior HOMO distributions spread over the nitrogen-donor (as well as somehow oxygen- donor in L2) groups of L1 and L2 macrocycles were the key factor for the observed Kb value enhancement. Thermodynamic stabilities for these complexes have also been determined employing... 

Using seven bond-order potentials and five force fields, the fundamental natural frequency of C60,Ag(1) (breathing mode), and two other basic modes, namely Hg(1) (squashing mode) and T2g(1) are calculated. The same frequencies are derived through a DFT B3LYP/6-31G(d) calculation. Furthermore, the results are compared with Raman and IR scattering data, and previous quantum mechanics calculations, depicting the strength of each interatomic potential in predicting the vibrational properties of Buckminsterfullerene. AIREBO, which is formulated for analyzing hydrocarbons, shows the highest accuracy among all of the potentials under investigation. In general, bond-order potentials predict a... 

Chitosan films have a great potential to be used for wound dressing and food-packaging applications if their physicochemical properties including water vapor permeability, optical transparency, and hydrophilicity are tailored to practical demands. To address these points, in this study, chitosan (CS) was combined with polyvinylpyrrolidone (PVP) and graphene oxide (GO) nanosheets (with a thickness of ∼1 nm and lateral dimensions of few micrometers). Flexible and transparent films with a high antibacterial capacity were prepared by solvent casting methods. By controlling the evaporation rate of the utilized solvent (1 vol % acidic acid in deionized water), self-organization of GO in the... 

Abstract In this work, two [60] fullerene derivatives were employed as flow improvers for waxy crude oil to reduce problems caused by the crystallization of paraffin during the production and/or transportation of the crude oil. These amine-based derivatives of [60] fullerene have been applied as wax inhibitor for improvement of rheological performance as well as pour point depressant in a waxy crude oil. Moreover, the influence of these [60] fullerene derivatives on the viscosity and pour point was also investigated in an Iranian waxy crude oil sample. The [60] fullerene derivatives were simply prepared by stirring a solution of [60] fullerene and two lipophilic amines. The results similarly... 

In this paper, we have studied the motion of buckminsterfullerene (C60) on a gold surface by analyzing its potential energy and using classical molecular dynamics method. The results can be employed to investigate the motion of C60-based nanocars which have been made in recent years. For this purpose, we have studied the translational and rotational motions of C60 molecule independently. First, we have calculated the potential energy of a C60 molecule on a gold surface in different orientations and positions and employed this data to predict fullerene motion by examining its potential energy. Then we have simulated the motion of C60 at... 

In this paper a shell formulation is proposed for analyzing the torsional instability of carbon nano-peapods (CNPs), i.e., the hybrid structures composed of C60 fullerenes encapsulated inside carbon nanotubes (CNTs), based on the nonlocal elasticity theory. The nonlocal elasticity theory, as a well-known non-classical continuum theory, is capable to capture small scale effects which appear due to the discontinuities in nano-structures. Based on the derived formulation, the critical torsional moments for a pristine (10,10) CNT and C60@ (10,10) CNP are investigated as case studies. The results for the (10,10) CNT are compared with those of the available molecular dynamics simulations in the... 

The interaction of [60]fullerene with a series of 15-19-membered macrocycles containing an O 2N 2-donor set has been investigated by UV-visible spectroscopy. The formation constants arising from the complexation of [60]fullerene with these azacrown macrocycles, having various ring size, were determined in CHCl 3 media applying Benesi-Hildebrand equation. The stoichiometry has been found by the Job method in each case. The thermodynamic parameters, for example, formation enthalpies (δH o) and entropies (δS o), for these complexation were also determined. Experimentally, it was found that macroring size of the azacrown has a prominent effect on azacrown complexation with [60]fullerene in terms... 

Accurate prediction of static and dynamic response of nano structures under external excitations has been one of the interests of scientists in the last decade. Several applications of nano machines make it necessary to analyze their components, such as nano bearing, precisely. In this paper, the static and vibrational behavior of a fullerene as a sensitive part of nano bearing under external forces is simulated by a newly designed spherical super element. This super element is designed in such a way that the user can select as many numbers of nodes as desired, so that it can be implemented in different desired precisions. In this study, a 228-node super element, which is similar to a hollow... 

Accurate prediction of static and dynamic response of nano structures is one of the important interests of scientists in the last decade. Nano bearing as an important part of nano machines has been extensively implemented in recognizing and disassembling cancerous cells and building molecular support structures for strengthening bones. For this reason, Molecular Dynamic Method and some experimental methods are implemented in this area. As nano ball bearing is one of the most important components of nano machines, a large number of studies are concentrated to analyze it statically and dynamically. In this paper, a Fullerene is simulated by a spherical super element whose stress, deformation... 

This work studies the electrochemical growth behavior of cobalt nanowires in highly ordered aluminum oxide membrane. Considering the electrodeposition of metallic nanowires, cation concentration profile in each nano pore was calculated. With assumption of linear diffusion zone on the growing surface of nanowires, a modified Cottrell equation was evaluated. To confirm the model, the Co nanowires were electrodeposited into porous anodic aluminum oxide (AAO) templates and the mechanism of deposition was studied. Comparing the results of model and the experiments has proved the accuracy of the model. Also, it was observed that the growth of the Co nanowires was controlled mainly by diffusion... 

In this paper, the axial stability of single-walled carbon nanopeapods is studied based on an elastic continuum shell model. In order to model the non-bonded van der Waals interactions between host carbon nanotube and guest fullerenes, an equivalent pressure distribution is proposed and incorporated in the model. Deriving an explicit equation for the determination of critical axial load, it is concluded that the axial stability of a single-walled carbon nanopeapod is less than that of a carbon nanotube under otherwise identical conditions. In addition, it is shown that applying external pressure to the carbon nanopeapod decreases the axial compressive stability through reducing the critical...