International Journal Of Nanoscience and Nanotechnology
Volume:16 Issue: 1, Winter 2020

A modified morphology was introduced for poly(3-hexylthiophene):phenyl-C71-butyric acid methyl ester (P3HT:PC71BM) bulk heterojunction (BHJ) solar cells by thermal and solvent annealing treatments in the presence of hydrophilic-hydrophobic block copolymers. Power conversion efficiency (PCE) plummet was prohibited during both thermal and solvent treatments for all BHJ devices modified with either hydrophobic- or hydrophilic-based copolymers. It was originated from ever increasing trend of fill factor (FF) and increasing or marginally decreasing trend of short circuit current density (Jsc). Although PCEs were higher in untreated hydrophobic-compatibilized devices, the hydrophilic-compatibilized systems further benefited from thermal and solvent treatments. The vertical homogeneity increased for compatibilized BHJs during annealing processes, leading to very high FFs around 70%. The maximum values of Jsc and PCE for the well-controlled photovoltaic systems were 12.10 mA/cm2 and 4.85%, respectively.

Small changes in pressure or temperature, close to the critical point, lead to large changes in solubility of supercritical carbon dioxide (CO2). Environmentally friendly supercritical CO2 is the most popular and inexpensive solvent which has been used for preparation of nanodrugs and nanocarriers in drug delivery system with supercritical fluid technology. Delivery of a drug is one of the most challenging research areas in pharmaceutical sciences. With a combination of drugs and innovative delivery systems such as lipid nanocarriers, drugs efficiency and safety have been improved significantly. There are various techniques available to produce drug loaded solid lipid nanoparticles. Among them, supercritical fluid technology has been identified as potentially effective and applicable approach which has attracted increasing attention during recent years. This technique has several advantages such as avoid the use of solvents, particles are obtained as a dry powder, instead of suspensions, mild pressure and temperature conditions can be applied. Nevertheless, little attention has been paid to formation of drug loaded solid lipid nanoparticles by supercritical fluid technology. In this paper, we present a brief introduction to solid lipid nanocarriers. Then a general overview of different processes of supercritical fluid technology has been provided and also case studies are presented to show the potential benefits of this approach in drug loaded solid lipid nanoparticle production.

In this work, magnetic graphene oxide (MGO) was prepared by in situ synthesis of magnetite nanoparticles in the presence of graphene oxide (GO). The prepared nanocomposite was characterized by applying scanning electron microscopy (SEM), X-ray diffraction (XRD, Fourier transform infrared spectroscopy (FTIR) and vibrating sample magnetometer (VSM). MGO was applied as an efficient nano-sorbent for adsorptive removal of reactive red 195 (RR195). The adsorptive removal process of RR195 was modeled and optimized using the response surface methodology (RSM) based on central composite design (CCD). Important parameters influencing the adsorption of RR195 including pH, contact time, initial concentration of RR195 and adsorbent amount were selected as input variables for RSM. The highest adsorption capacity of MGO sorbent (77.2 mg g-1) was obtained at an initial dye concentration of 325 mg L-1, contact time of 65 min, adsorbent amount of 89.4 mg, and pH of 3.  Moreover, the adsorption isotherms and kinetics studies were performed, indicating that the adsorption process best fitted in pseudo-second-order model and Langmuir isotherm model, in which the maximum adsorption capacity, qm, was calculated to be 80 mg g-1.

In This research the effect of fluorine and chlorine substituents on the electronic and opticalproperties of pentacene molecule have been investigated based on density functional theory as implemented in SIESTA code. The results show thatthe full replacement of hydrogen atoms with fluorine and chlorine in pentacene molecule, leads to shrink the HOMO-LUMO gap by the value of 0.14 and 0.46 eV, respectively. Moreover, the cohesive energy of fluorinated (F-PENT) and chlorinated pentacene (Cl-PENT) follow F-PENT< PENT < Cl-PENT order with respect to the cohesive energy value of -7.54 eV corresponding to pristine pentacene.  Therefore F- PENT shows better stability than others. The results of optical properties demonstrate that fluorinated and chlorinated pentacene have greater dielectric constant and refractive index with respect to pristine pentacene. The reflectivity feature along the long axis of pentacene molecule undergoes a red shift and accordingly the violet color of pentacene changes to blue and green by the influence of fluorination and chlorination, respectively. These results can be utilized to improve molecular electronic and optical devices.

ZnO structures with different dopants (1mol% Cr, Mn, Fe, Co, Cu and Ni) have been synthesized via a simple hydrothermal method using sucrose as a template. These doped ZnO nanostructures characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and photoluminescence (PL). The photocatalytic property of these synthesized materials was studied by a photocatalytic characterization system. The PL results confirmed that these dopants showed a significant effect on photoluminescence properties of ZnO structure. Among the synthesized photocatalysts, Ni doped ZnO showed a significant enhancement of photodecolorization capability (98.6 %) toward Congo red dye in UV irradiation. Also, it showed the highest dye adsorption (80%) at dark conditions. The improvement of decolorization of this photocatalyst might be attributed to enhancement the chance of the separation of electrons and holes, high capacity of dye adsorption and presence of defects in its structure. Preliminary experiment suggested Ni doped ZnO as effective photocatalyst for treating some pollution such as azo dyes.

The growth and structural study of Nickel doped Cobalt ferrite thin films on glass substrate using spray pyrolysis technique have been done. The structural studies confirmed the growth of polycrystalline film having cubic structure with Fd3m space group. The x ray density was found to increase with Ni concentration, where as the reduction, in crystalline size, was found in XRD measurements. The AFM studies also showed the grain size and roughness of the films decrease with increase in Ni concentration.