Nanochemistry Research
Volume:5 Issue: 2, Summer-Autumn 2020

Bis (1(3-trimethoxysilylpropyl)-3-methyl-imidazolium) nickel tetrachloride tethered to colloidal nano-silica (ionic liquid/ colloidal nano-silica) has been used as an effective catalyst for the preparation of benzopyranophenazines through the reaction of hydroxynaphthoquinone, o-phenylenediamine, benzaldehydes, and malononitrile under ultrasonic irradiations in ethanol. The catalyst has been characterized by 1H NMR, FE-SEM, EDS, DLS and TGA. Experimental simplicity, excellent yields in short reaction times, wide range of products and applying the sonochemical methodology as an efficient method and innocuous means of activation in synthetic chemistry for the synthesis of medicinally privileged heterocyclic molecules are some of the substantial features of this procedure. The present catalytic method is extensible to a wide diversity of substrates for the preparation of a variety-oriented library of phenazines.

Some pulsed tissues are replaced with non-pulsed damaged tissue, which jeopardizes heart function after a heart attack. The restoration is performed by a patch tissue to repair defective tissues. It is supposed to attach to the outside of the heart and connect to the wounded area. The above patch is made of a conductive polymer on which a separate electrical polymer called "alginate" through a process called 3D bioprinter. The mechanism of the following patch for biological and cell behavior has to be investigated. Besides, we explain the results of the combination of these polymers with natural and synthetic polymer composites. As a natural and biological soft patch for cardiovascular disease (CVD) the adhesion of cells to patch is more efficient and important. In this study, we used a novel technique to print sodium alginate for CVD problems with soft hydrogel patch loading with the restorative drug. In other words, by producing soft tissue patches, researchers and clinical surgeons can obtain more desirable properties made of natural and synthetic polymer composites for the treatment of heart disease. In this study, four CVD patches fabricated using 3D bioprinter X4bioFab with various amounts of drug on their surfaces containing 2%, 4%, 6%, and 8%. The obtained values for mechanical and biological performance present proper features for the sample containing a 6% drug. The results indicated the prepared patch can be a suitable candidate for heart disease with sufficient cell attachment after a while.

Metallic nanoparticles have extraordinary antibacterial property. The silver NPs capped by biomolecules from medicinal plants can be disastrous to pathogens. For the first time, green silver nanoparticles (EcS-Ag NPs) were successfully synthesized from the Ethiopian medicinal plant Echinops sp . The most advanced techniques were employed to characterize the NPs. The presence of absorbance maxima, λmax,at 454 nm confirms the formation of EcS-Ag NPs. The UV-DRS studies revealed the band gap of 2.22 eV for NPs. The role of biomolecules as capping agents for EcS-Ag NPs was authenticated by FT-IR spectra. The presence of 4 sharp peaks in the XRD pattern of NPs confirmed the highly crystalline nature of NPs. The purity of the NPs was corroborated by SEM-EDAX analysis. The mean particle length of NPs was found to be 33.86 nm. In addition, TEM micrographs revealed the presence of EcS-Ag NPs with varieties of nano-sized shapes. TEM-HRTEM-SAED analysis authenticated the presence of silver NPs with interplanar spacing value of 0.2418 nm which conformed to Ag (111) lattice fringes of NPs. The EcS-Ag NPs showed significant synergistic antibacterial effects against S. aureus, E. coli, P. aeruginosa, and E. aerogenes. The uppermost zone of inhibition of 18 mm was found against S. aureus bacteria. EcS-Ag NPs exhibited better antibacterial activities against gram-positive and gram-negative bacteria.

Nano-NiZr4 (PO4)6 has been used as an effective and retrievable heterogeneous catalyst for the synthesis of pyrimidines through the reaction of benzaldehydes, guanidinehydrochloride and malononitrile under reflux conditions in ethanol. Experimental simplicity, wide range of products, excellent yields in short reaction times, reusability of the catalyst and low catalyst loading are some of the substantial features of this procedure. The best results were gained in EtOH and we found the convincing results for the synthesis of pyrimidines in the presence of nano-NiZr4 (PO4)6(3 mg) under reflux conditions. The present catalytic method could be extended to a wide diversity of substrates for the synthesis of a variety-oriented library ofpyrimidines.

In this paper, semi-solid precursor of chromium was prepared from the reaction of Cr(NO3)3 and oxalic acid at the presence of NaOH. Then, Cr2O3 nanoparticles were prepared by solid-state thermal decomposition of this precursor at 500 and 600 ºC at standard atmospheric pressure for 3 h. The as-prepared Cr2O3 nanoparticles were characterized by Fourier transform infrared (FT-IR), ultraviolet-visible (UV-Vis) spectroscopy, X-ray powder diffraction (XRD), transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). The sharp vibration bands in FT-IR spectra and high intensity peaks in XRD patterns confirmed the preparation of pure, single rhombohedral phase and crystalline Eskolaite structure of Cr2O3 nanoparticles. A broad absorption peak appeared at UV-Vis spectra indicates the d3 electronic transition of Cr3+. The TEM images show that the particles are similar and a little agglomerated with the average crystal size of < 100 nm. The VSM results predict that the as-prepared Cr2O3 nanoparticles are weak ferromagnetic and paramagnetic.

M3(OH)2V2O7·nH2O ( M : Co, Ni, Cu, Zn) nanostructures were synthesized by a simple and economic chemical precipitation route. For Co and Ni compounds, very small (~9 nm), irregularly shaped and poor crystalline nanoparticles occurred, probably due to high tendency for complexing with ammonia molecules releasing from ammonium metavanadate. However, more crystalline Co compounds could be synthesized in high reactant concentrations, but not for Ni.  Zn and Cu compounds are well crystallized in the hexagonal and monoclinic unit cell, respectively. Their shapes were nanoflake or nanoplate and their thickness were about 20 nm and 25 nm, respectively. Both have an average diameter of less than 500 nm. The chemical formulas determined were Co3V2O7(OH)2·2.8H2O, Ni3V2O7(OH)2·5.6H2O, Cu3V2O7(OH)2·2H2O and Zn3V2O7(OH)2·2.8H2O. The band gaps of samples were found in the range from 3.22 to 4.34 eV. Magnetic measurements show that all Co samples have a magnetic transition from ferromagnetic (FM) to paramagnetic (PM) around 300 K, on the ground that samples with FM characteristics and coupling at 5 K temperature turn into PM samples at room temperature. These results are important for large-scale synthesis of nanovanadate structures.

A novel resorcinol formaldehyde hydrogel-based matrix was synthesized to stabilize indium sulfide / graphitic carbon nitride (In2S3/ g-C3N4) heterojunction, and the adsorption performance and photocatalytic degradation activity of RhB over In2S3/ g-C3N4 in hydrogel were explored. The g-C3N4 nanosheets and In2S3 nanoparticles were synthesized and characterized by Fourier-transform infrared spectroscopy (FTIR), and UV-Vis diffuse reflectance spectroscopy (DRS). In2S3 andg-C3N4 were stabilized in hydrogel, and In2S3/ g-C3N4 in hydrogelwas characterized by FFIR, DRS, X-ray diffraction, Brunauer-Emmett-Teller (BET) surface area analysiand Barrett-Joyner-Halenda (BJH) pore volume and pore size analysis, field emission scanning electron microscopy, and energy dispersive X-ray.The measured bandgap for In2S3/ g-C3N4 in hydrogel was 2.1 eV. BET results showed that the presence of heterojunction in the synthesis process of hydrogel dramatically increases the specific surface area about 20 times. In2S3/ g-C3N4 in hydrogeladsorbed RhB (25 ml of 3 ppm solution) about 72% and removed RhB under light irradiation about 89% in 120 min.The RhB removal reactions over In2S3/ g-C3N4 in hydrogel in both dark and under light irradiation conditions follow the first-order kinetic. This study reveals a new potential application of resorcinol formaldehyde hydrogel as a porous matrix to stabilize nano-size photocatalysts.

Pseudomonas aeruginosa is a significant cause of nosocomial infections. Infection caused by this organism is difficult to treat due to the presence of its innate resistance to many antibiotics. Conjugation of antimicrobial drugs with nanoparticles has emerged as an innovative and promising alternative that enhances therapeutic effectiveness. The current study focuses on the use of gold nanoparticles (GNPs) as a carrier to enhance the antibacterial effect of amikacin against P. aeruginosa. Amikacin was conjugated with GNPs. The success of conjugation was studied by UV/Vis and FTIR spectroscopies. The labeling efficiency was measured by HPLC and atomic absorption spectrometer analyses. The antibacterial activity of amikacin-GNPs conjugate was investigated by disc diffusion and liquid broth dilution methods. The labeling efficiency showed that 450 amikacin molecules were attached to each GNP. The zone of growth inhibition of amikacin-GNPs complex and amikacin by disc diffusion method were 37± 0.118 and 35± 0.149 mm. Minimum inhibitory concentration (MIC) of the conjugate and amikacin alone were determined 23.43 and 46.87, mg/ml, respectively. Minimum bactericidal concentration (MBC) of the conjugate and amikacin alone were determined 46.87 and 93.75 mg/ml, respectively. The results showed the enhanced antibacterial effect of amikacin-GNPs complex in comparison with amikacin alone against P. aeruginosa.

The present study describes a new approach for the investigation of electrocatalytic oxidation of hydrazine by using a glassy carbon electrode (GCE) modified by graphene chitosan nanocomposite (Gr-Cs) and Rutin (Ru). The heterogeneous electron transfer rate constant (ks) and the surface coverage of immobilized Ru on the Gr‒Cs/GCE were obtained as 63 s−1 and 4.48×10−11 mole cm−2, respectively. The constructed sensor showed excellent electrocatalytic activity toward oxidation of hydrazine. The catalytic rate constant (kcat) of the modified electrode toward N2H4 is 6.3 ×103 M-1s-1. Linear relationship between amperometric current response and hydrazine concentration was observed in the range from 0.3 to 1500 µM and the limit of detection was 90 nM (S/N=3). In addition, the modified electrode has an excellent anti-interference property in the presence of other potentially interfering species as well as a good operational stability. To evaluate the applicability of the proposed sensor, it was employed to determine hydrazine in drinking water sample.

Surface of graphene oxide was modified by grafting 3-aminopropyl-triethoxysilane to have the positive charge, and thus, to provide sites for the immobilization of H3PW12O40. This modified-nanosized material (PW12-APTMS@GO) was characterized by FTIR, XRD, BET, SEM and TEM. XRD shows that the structure of graphene remains intact after two steps modifications, while spectral techniques show the successful grafting of the PW12 on the graphene layers. PW12-APTMS@GO was used as a catalyst in the photodecolorization process of methylene blue dye in aqueous solution under sunlight radiation.The results of UV–vis spectra changes and HPLC methods indicate that photocatalytic process can be used for complete decolorization and mineralization of the pollutant in a photochemical reactor. The optimum values of the experimental parameters which affect the degradation efficiency were obtained as: 0.015 g L−1 of the photocatalyst, 30 ppm dye concentration and pH 3.0. It was found that the catalyst exhibited significantly high catalytic stability, and the activity loss is negligible after five methylene blue degradation cycles.

Cationic poly(Acrylonitril-co-Acrylamidopropyl-trimethyl Ammonium Chloride) (p(AN-co-APTMACl)) hydrogels in bulk were synthesized by using acrylonitrile (AN) and 3-acrylamidopropyl-trimethyl ammonium chloride (APTMACl) as monomers. The chemical structure of synthesized (p(AN-co-APTMACl)) macroporous hydrogel was confirmed by Fourier Transform Infrared (FT-IR), scanning electron microscopy (SEM). P(AN-co-APTMACl) has been successfully utilized for the in situ synthesis and stabilization of silver nanoparticles within the hydrogel matrix. These hydrogel composites were characterized by Fourier transform infrared (FT-IR), field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) and atomic absorption spectroscopy (AA). The morphology of the p(AN-co-APTMACl) reveals the formation of homogeneous and highly porous material. Catalytic activity of p(AN-co-APTMACl)-Ag catalyst was investigated in the aerobic oxidation of olefins, reduction of 4-nitrophenol and hydrolysis of sodium borohydride by emphasizing the effects of different parameters such as temperature, substituent effect, etc. The catalyst was easily recovered from the reaction medium and it could be re-used for other five runs without significant loss of activity.

The antibacterial activity of a metal-organic nanocapsule [Cu2(dpa)2(bpy)2]·4H2O (1), (H2dpa = diphenyl-2,2ꞌdicarboxylic acid and bpy = 2,2ꞌ bypyridine) was investigated against gram-positive and gram-negative bacterial strains. First, [Cu2(dpa)2(bpy)2]·4H2O was synthesized by both the reflux and sonochemical processes. Then, the obtained products were characterized by powder X-ray diffraction (PXRD), IR spectroscopy and scanning electron microscopy (SEM). Finally, their antibacterial performance was investigated by the agar well diffusion method. The results showed that the compound is active against S. aureus, whereas, it is inert against E. coli bacteria. The fact that bpy exhibited a high antibacterial performance against E. coli, while compound 1 samples were inert against E. coli bacteria shows that ligand release in metal-organic nanocapsule of 1 does not occur. It seems that the mechanism of compound 1 for its antibacterial activity is different from other reported compounds and is not attributed to Cu2+ and ligand release from 1, because of its high chemical stability.

In this work, we synthesized a new complex of silver(І) with a schiff-base ligand 2,5-bis(3-pyridyl)-3,4-diaza-2,4-hexadiene (L=3-bpdh),[Ag(3-bpdh)(NO3)]n (1) and characterized by Infra-Red (IR) spectroscopy. The nano-rods of this complex were synthesized by sonochemistery method and characterized by IR spectroscopy and Scanning Electron Microscopy (SEM). The nanoparticles of silver(I) oxide were obtained by direct thermolysis at 700°C on air atmosphere and characterized by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray analysis (EDAX). The Schiff-base ligand, bulk and nano forms of complex (1) and silver (І) oxide nanoparticles have been screened for antibacterial activities. The antibacterial activities have investigated against two gram positive (Staphylococcus aureus, Enterococcus faecalis) and two gram negative (Escherichia coli, Pseudomonas aeruginosa) bacteria. The results revealed that all compounds exhibit antimicrobial activities, compounds 1 in nano-scale and silver(I) oxide have stronger antibacterial effect in comparison with Schiff base ligand and in comparison with bulk form of compounds 1

In this study, Tb-doped PbTe nanoparticles with variable Tb3+ content were synthesized by a simple hydrothermal technique. The synthesized nanoparticles were characterized by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and powder X-ray diffraction (XRD). XRD patterns indicated that the particles were excellently crystallized and attributed to the cubic PbTe phase. The SEM images certify that the substitution of Tb into the lattice of PbTe does not change the morphology of PbTe nanoparticles. SEM images displayed that the size of the particles was in the range of 25-80 nm. The energy of the bandgap of doped-PbTe and PbTe nanoparticles expected from the chief absorption edges of the UV-Vis diffuse reflectance spectrum. Blue shifts in DRS spectra of PbTe were noticed by increasing the concentration of the Tb3+ ions. The incorporation of Tb3+ into the PbTe lattice was confirmed by the XPS technique. The electrical conductance of various Tb-doped PbTe samples is higher than the pure PbTe, and elevates with temperature.