Influence Of ZnO Nanoparticles Research Articles

Influence of ZnO Nanoparticles on Early Growth Stage of Fragrant Rice at Low Temperature (LT) Stress

Influence of ZnO Nanoparticles on Early Growth Stage of Fragrant Rice at Low Temperature (LT) Stress

The influence of ZnO nanoparticles on mechanical and early-age hydration behaviour of cement paste

The influence of ZnO nanoparticles on mechanical and early-age hydration behaviour of cement paste

Influence of ZnO nanoparticles on the properties of biodegradable PBAT matrix for food packaging application

Currently, the use of biodegradable polymers for packaging application has been an imperative topic due to the environmental damage caused by non-biodegradable materials. In the present study, PBAT/ZnO biodegradable nanocomposites were prepared by melt processing and characterized by FEG-SEM, DSC, XRD, TDNMR and water activity analysis. The main results showed an increase in the Tc values for all produced formulations, indicating a change in the crystalline profile of the PBAT, which was corroborated by XRD results. FEG-SEM showed that the systems containing up to 1 wt.% of ZnO showed better nanoparticles dispersion, while formulations containing 3 and 5 wt.% of ZnO presented large aggregates. TDNMR provided a more detailed assessment, showing that PBAT/ZnO systems containing 0.5 and 5 wt.% of ZnO presented a higher heterogeneity at molecular level. Finally, water activity analysis showed that ZnO addition promoted an increment in the biosafety levels compared to neat PBAT, making the PBAT/ZnO nanocomposites more promising for food packaging application.

Influence of ZnO Nanoparticles on the Properties of Ibuprofen-Loaded Alginate-Based Biocomposite Hydrogels with Potential Antimicrobial and Anti-Inflammatory Effects.

Hydrogels are a favorable alternative to accelerate the burn wound healing process and skin regeneration owing to their capability of absorbing contaminated exudates. The bacterial infections that occur in burn wounds might be treated using different topically applied materials, but bacterial resistance to antibiotics has become a major problem worldwide. Therefore, the use of non-antibiotic treatments represents a major interest in current research. In this study, new antibiocomposite hydrogels with anti-inflammatory and antimicrobial properties based on hyaluronic acid (HA) and sodium alginate (AG) were obtained using 4-(4,6-dimethoxy-1,3,5-triazinyl-2)-4-methylmorpholinium chloride as an activator. The combination of Ibuprofen, a non-steroidal anti-inflammatory drug commonly used to reduce inflammation, fever and pain in the body, with zinc oxide nanoparticles (ZnO NPs) was used in this study aimed at creating a complex hydrogel with anti-inflammatory and antimicrobial action and capable of improving the healing process of wounds caused by burns. FTIR spectra confirmed the cross-linking of AG with HA as well as the successful incorporation of ZnO NPs. Using electronic microscopy, it was noticed that the morphology of hydrogels is influenced by the incorporation of ZnO nanoparticles. Moreover, the incorporation of ZnO nanoparticles into hydrogels also has an influence on the swelling behavior at both pH 7.4 and 5.4. In fact, the swelling rate is lower when the amounts of the activator, HA and ZnO NPs are high. A drug release rate of almost 100% was observed for hydrogels without ZnO NPs, whereas the addition of nanoparticles to hydrogels led to a decrease in the release rate to 68% during 24 h. Cellular viability tests demonstrated the non-cytotoxic behavior of the hydrogels without the ZnO NPs, whereas a weak to moderate cytotoxic effect was noticed for hydrogels with ZnO NPs. The hydrogels containing 4% and 5% ZnO NPs, respectively, showed good antimicrobial activity against the S. aureus strain. These preliminary data prove that these types of hydrogels can be of interest as biomaterials for the treatment of burn wounds.

Responses of two strawberry cultivars to NaCl-induced salt stress under the influence of ZnO nanoparticles

Salinity stress is one of the most serious impacts of climate changes on agriculture production, especially in salt sensitive crop plants, like strawberry. Currently, the utilization of nanomolecules in agriculture is thought to be a useful strategy to compact abiotic and biotic stresses. This study aimed to investigate the effect of zinc oxide nanoparticles (ZnO-NPs) on the in vitro growth, ions uptake, biochemical and anatomical responses of two strawberry cvs (Camarosa and Sweet Charlie) under NaCl-induced salt stress. A 2x3x3 factorial experiment was conducted, with three levels of ZnO-NPs (0, 15 and 30 mg 1-l) and three levels of NaCl-induced salt stress (0, 35 and 70 mM). The results showed that increased levels of NaCl in the medium had led to decrease in shoot fresh weight and proliferative potential. The cv Camarosa was found to be relatively more tolerant to salt stress. Additionally, salt stress leads to an accumulation of toxic ions (Na + and Cl-), as well as a decrease in K + uptake. However, application of ZnO-NPs at a concentration of 15 mg 1-l was found to alleviate these effects by increasing or stabilizing growth traits, decreasing the accumulation of toxic ions and the Na+/K + ratio, and increasing K + uptake. Additionally, this treatment led to elevated levels of catalase (CAT), peroxidase (POD) and proline content. The positive impacts of ZnO-NPs application were reflected on the leaf anatomical features, being better adapted to salt stress. The study highlighted the efficiency of utilizing tissue culture technique in screening of strawberry cultivars for salinity tolerance under the influence of NPs.

The influence of ZnO nanoparticles on horizontal transfer of resistance genes in lab and soil conditions

Antibiotic resistance is a severe problem that threatens the achievements of modern medicine. Metallic nanoparticles may promote the horizontal transfer of resistance genes due to their toxicity to bacterial cells and metal-induced co-selection mechanisms. In this study, we investigated the toxicity of ZnO nanoparticles to E. coli DH5α laboratory strain and the abundance of soil microbial community. Moreover, the influence of ZnO nanoparticles on resistance gene transfer in laboratory and soil conditions was evaluated. ZnO nanoparticles at concentrations up to 10 mg L−1 reduced the survival of E. coli cells by 14.6% and increased the transformation frequency by almost 1.8 fold. In soil, ZnO nanoparticles at a concentration of 1000 mg kg−1 affected the total abundance of bacteria, causing a decrease in the 16S rRNA gene copy number. We did not detect the presence of 11 target antibiotic resistance genes (sul1, sul2, imp2, imp5, blaCTX-M, ermB, mefA, strB, aadA1, tetA1, tetB), which confer resistance to five classes of antibiotics in soil treated with ZnO nanoparticles. No elevated conjugation frequency was observed in soil microbial communities treated with ZnO nanoparticles. However, the increase in czcA gene copies indicates the spread of genetic elements harbouring metal resistance. The data shows that metallic nanoparticles promote the spread of antibiotic and metal resistance genes. The broad implication of the present research is that the inevitable nanoparticles environmental pollution may lead to the further dissemination of antibiotic resistance and profoundly influence public health.

The influence of ZnO nanoparticles on the structural, optical and dielectric properties of Polyvinyl alcohol films

Polyvinyl alcohol/Zinc oxide (PVA/ZnO) nanocomposite films with various weight percentages of ZnO nanoparticles (0 wt%, 5 wt%, 10 wt%, 15 wt%, 20 wt%) were prepared by solution casting method. The structural, optical and morphological properties of the synthesized samples were characterized by X-ray diffraction (XRD), UV–Visible spectroscopy, Fourier transform Infrared spectroscopy (FTIR) and Scanning electron microscope (SEM). X-ray diffraction studies confirms the formation of PVA/ZnO nanocomposites. From the UV–vis absorbance spectra, the band gap energy of the samples was calculated and its value decreases with increasing the wt% of ZnO into the PVA matrix. The transmittance of the nanocomposites in the visible region is decreased with increasing the concentration of ZnO into the PVA matrix and completely blocked in the UV region. These behaviours suggests that the nanocomposite materials could be used as UV shielding materials. The FTIR analysis indicates physical interaction between hydroxyl group of PVA and ZnO. SEM shows the dispersion of ZnO on the surface of PVA matrix. The dielectric properties and AC conductivity measurement in the frequency range 100 Hz to 1 MHz reveals the maximum dielectric constant at PVA/5 wt% ZnO nanocomposite.

Influence of ZnO nanoparticles and dispersant in Baheda oil biodiesel blend on the assessment of performance, combustion, and emissions of VCR diesel engine

Influence of ZnO nanoparticles and dispersant in Baheda oil biodiesel blend on the assessment of performance, combustion, and emissions of VCR diesel engine

Sustainable microwave synthesis of biodegradable active packaging films based on polycaprolactone and layered ZnO nanoparticles

Sustainable nanocomposites based on biodegradable polycaprolactone (PCL) matrix and ZnO nanoparticles (ZnONPs) functionalized with ionic liquid (IL) were prepared via bulk in-situ ring opening polymerization of ε-caprolactone (εCL). PCL-ZnONPs nanocomposite films were examined in terms of mechanical, thermal and barrier properties. The influence of ZnONPs on the potential antimicrobial effect and biodegradation of PCL-ZnONPs films was investigated. Introduction of IL-ZnONPs NPs (3.0 wt%) into PCL matrix resulted in significant decrease of water vapor permeation (46%), induced bactericidal effect against food-born pathogenic bacterium E.coli and enhanced biodegradation rate of the prepared nanocomposite film. Therefore, these materials present high application potential as active bio-packaging films, e.g. for food storage.

Influence of ZnO NPs on morphological and electro-optical properties of polymer-dispersed liquid crystals

ABSTRACT Polymer dispersed liquid crystal (PDLC) is a striking material and has an enormous role in electro-optic display devices. In this paper, nanoparticles (NPs) doped PDLCs were prepared from a mixture of UV curable liquid polymer, nematic liquid crystal (LC), and ZnO NPs by the polymerisation induced phase separation (PIPS) process. The morphological and electro-optical properties of PDLC with various diluent contents, liquid crystal contents, and nanomaterial doping were investigated comprehensively, and a morphological study shows that multiple factors jointly affected the droplet size, thereby altering a variety of properties including driving voltage and contrast. Compared with pure PDLC, the NPs doped PDLC reduces the threshold voltage from 39.5 V to 21.1 V and the driving voltage from 71.0 V to 45.0 V, which greatly improves the electro-optical performance of PDLC with a few sacrifices in contrast. This opens new possibilities for achieving a wide range of applications for energy-efficient PDLC.

Fluctuation induced conductivity and pseudogap state studies of Bi1.6Pb0.4Sr2Ca2Cu3O10+\u03b4 superconductor added with ZnO nanoparticles

The major limitations of the Bi1.6Pb0.4Sr2Ca2Cu3O10+δ superconductor are weak flux pinning capability and weak inter-grains coupling that lead to a low critical current density and low critical magnetic field which impedes the suppleness of this material towards practical applications. The addition of nanoscales impurities can create artificial pining centers that may improve flux pinning capability and intergranular coupling. In this work, the influences of ZnO nanoparticles on the superconducting parameters and pseudogap properties of the Bi1.6Pb0.4Sr2Ca2Cu3O10+δ superconductor are investigated using fluctuation induced conductivity analyses. Results demonstrate that the ZnO nanoparticles addition improves the formation of the Bi1.6Pb0.4Sr2Ca2Cu3O10+δ phase significantly. Various superconducting parameters include coherence length along c-axis (ξc(0)), penetration depth (λpd(0)), Fermi velocity (vF), Fermi energy (EF), lower and upper critical magnetic fields (Bc1(0) and Bc2(0) respectively) and critical current density (Jc(0)), are estimated for samples with different amounts of ZnO nanoparticles. It is found that the values of the Bc1(0), Bc2(0), and Jc(0) are improved significantly in the 0.2 wt% ZnO added sample in comparison to the ZnO-free sample. The magnitude and temperature dependence of the pseudogap Δ*(T) is calculated using the local pairs model. The obtained values of Tpair, the temperature at which local pairs are transformed from strongly coupled bosons into the fluctuating Cooper pairs, increases as the added ZnO nanoparticles concentration enhances up to 0.2 wt%. Also, the estimated values for the superconducting gap at T = 0 K (Δ(0)) are decreased from about 26 meV in ZnO-free sample to about 22 meV in 0.2 wt% ZnO added sample and then increases for higher values of additive.

Influence of ZnO nanoparticles on the performance of LED based on oligomer thin films

In this work, a set of thin films of ZnO nanoparticles doped with a conjugated oligomer {9,9,9′,9′,9″,9″-hexakis(hexyl)-2,7′;2′,7″-trifluorene} has been prepared. The optical and electrical measurements on pure oligomer, ZnO nanoparticles, and blended thin films have been investigated. The absorption spectra of the pure oligomer in thin films showed a single band at 350 nm. When the thickness was increased, there was no new band detected at the end of the spectrum. This is a strong indication that the oligomer cannot be present in the dimeric state. On the other hand, the photoluminescence (PL) spectra of the oligomer showed two distinguished peaks at 400 and 420 nm due to the monomer and excimer states, respectively. Furthermore, the results showed that the PL spectrum of the oligomer was affected by the thickness. For the blended thin films with different ratios of ZnO nanoparticles, the PL spectra showed an enhancement in intensity by increasing the concentration of ZnO nanoparticles. For the electrical properties, the addition of ZnO nanoparticles to oligomer had increased the current and luminescence. The luminescences of the pure and blend film at 10 V had reached 1000 and 4200 cd/m2, respectively; and the turn-on voltage was reduced from 10.5 to 5.8 V. The light emission in the device is due to the Auger-assisted energy up-conversion process. The lifetime of the blend’s diodes measured under standard atmospheric conditions was greatly improved.

The Influence of ZnO nanoparticles in the epoxy resin on the complex permittivity and dissipation factor

Abstract Epoxy resins are used as electro-insulating materials because they have great electro-insulation properties, adhesion, chemical resistance, and minimal shrinkage during curing. Epoxy nanocomposites have gained much interest in the area of nanotechnology, because of the ease of manufacture and the significant gain in properties. The influence of the various concentration of ZnO nanoparticles in epoxy resin Vukol 022 on the changes of the complex permittivity and dissipation factor has been measured at the temperature range from 20 °C to 120 °C. Frequency dependences of these parameters were measured within the frequency ranges from 1 mHz to 1 MHz by a capacitance method. The 0,5 wt.% nanoparticles caused a decrease of the real part of the complex relative permittivity. The higher concentration of nanoparticles for frequencies above 10 Hz had higher real relative permittivity as pure epoxy resin. At the study of the influence of temperature on dissipation factor, α-relaxation process and its shift to lower frequencies with ZnO fillers were observed.

Influence of ZnO nanoparticles on the polarization, dielectric and electro-optic behaviour in the smectic C* and hexatic I* phases

Here we report the results of the dielectric and polarization measurements in the smectic and the tilted hexatic phases of a liquid crystal-nano composite consisting of commercially available ferroelectric liquid crystal (FLC) doped with the ZnO nanoparticles (NPs). It has been observed that the inclusion of NPs not only decreases in the transition temperature but also dielectric strength of the Goldstone mode without altering the associated relaxation frequency. An additional relaxation observed for the FLC-ZnO nanocomposite, but not present in the pure material is attributed to the manifestation of the primary director mode. The observed results are analyzed using the generalized Landau model to understand the effect of the coupling between the polarization and optical tilt angle. While there is no change in either the magnitude of the tilt or the polarization across the orthogonal to tilted smectic phase transitions, clear changes are seen for both the parameter across the transition to the hexatic phase. The FLC-ZnO nanocomposite exhibits decreased rotational viscosity and a faster response time, a feature attractive from an application point of view.

Evaluation of phytotoxicity, cytotoxicity, and genotoxicity of ZnO nanoparticles in Vicia faba

Due to the accelerating use of manufactured nanomaterials, more research is needed to define their impact on plants. The present investigation aimed at evaluating the effect of different levels (0.0, 10, 25, 50, and 100mg/L) of ZnO nanoparticles (NPs) on Vicia faba during seed germination and seedling establishment. Additionally, V. faba root meristems were used as a model to monitor the cytotoxic and genotoxic effects resulting from exposure to ZnO NPs. The influence of ZnO NPs on three isoenzyme systems, peroxidase, α, and β esterase, was also evaluated using native-PAGE. Our results showed that lower concentrations of ZnO NPs (especially 10 and 25mg/L) enhanced seed germination and improved seedling growth, while higher concentrations (100 and 200mg/L) resulted in phytotoxicity. Cytological investigations of ZnO NPs-treated V. faba root cells denoted the clastogenic and aneugenic nature of ZnO NPs. Differential increase in mitotic index and significant alterations in cell cycle were observed upon exposure to ZnO NPs. High concentrations of ZnO NPs markedly induced chromosomal aberration, micronuclei, and vacuolated nuclei formation. Chromosomal breakage, chromosomal bridges, ring chromosomes, laggard chromosomes, and stickiness were also observed at a higher rate. The PAGE analysis showed that ZnO NPs treatments altered the expression patterns of all studied enzyme systems. Collectively, results from this work will help to further understand the phytotoxic effects of nanomaterials.

Studies on Optical Characteristics of Multicolor Emitting MEH-PPV/ZnO Hybrid Nanocomposite

ABSTRACTThe present work endeavors towards the scientific study on influence of ZnO nanoparticles on the optical characteristics of Poly [2 Methoxy (5, 2′ Ethylhexyloxy)-P-Phenylenevinylene] (MEH-PPV), a light emitting polymer. Hybrid nanocomposites of MEH-PPV were prepared by dispersing ZnO nanorods at loading concentrations of 1 wt. % and 3 wt. %. The structural characteristics of the hybrid composites were investigated using FTIR spectroscopy and X-ray diffraction. The UV absorption spectra and Photoluminescence emission spectra were analyzed in order to study the optical characteristics of nanocomposite. The optical constants were determined and the suitability of the composites for light emission was analyzed. The incorporation of ZnO nanorods facilitates the shift in emission wavelength and witnesses the color tuning ability and multicolor emission from the composite.

Influence of ZnO nanoparticles on anammox granules: The inhibition kinetics and mechanism analysis by batch assays

The spread application of nanoparticles (NPs) would cause instability on anaerobic ammonium oxidation (anammox) process. The present study focused on the short-term evaluation of ZnO nanoparticles (NPs) on anammox process by batch tests. Results indicated that a significant inhibition occurred under ZnO NPs stress of 5–100 mg gVSS−1. The half inhibitory concentration (IC50) of ZnO NPs was found to be 11.6 mg gVSS−1. The release of zinc ions from ZnO NPs dissolution was confirmed to be the main mechanism of inhibition on anammox activity. Haldane kinetic model simulation results confirmed that ZnO NPs imposed a non-competitive inhibition on nitrite conversion by decreasing maximum nitrogen removal rate (qmax), while they showed a competitive inhibition on ammonium conversion kinetics with affinity constant (Ks) increasing by 6 times. From the competitive inhibition results, it is suggested that the inhibition caused by ZnO NPs could be alleviated and recovered under higher ammonium concentrations.

Mechanical Characteristics of Micro and Nano Silica, ZnO and Chitin Powder Filled Unsaturated Polyester Composites

Objectives: In this study stir processing method is used to increase the strength of polymer with the addition of reinforcements such as micro and nano silica, ZnO and chitin powder. Methods/Statistical Analysis: produced with this process are the production of parts having good resistance to solvents like HCl and H 2 SO 4 being environmental friendly. Silica (micro and nano), chitin and ZnO were added into polyester resin in different fractions as 2%,4%,6% and 10% through mechanical stirrer at 1000 rpm for 1 h. Accelerator and catalyst were added and stirred using a glass rod. The influence of ZnO nano particles with the addition of silica and chitin powder on the mechanical properties like tensile strength and hardness were investigated. The comparison of different weight fractions is also studied. Findings: By adding ZnO nano particles with micro silica and chitin the tensile property of polyester composite was increased. The hardness increased with the addition of Silica (micro and nano) and ZnO whereas, it decreased with the addition of chitin powder. Application/Improvements: Investigating the effect of Silica (micro and nano) and chitin in addition to the ZnO nano particles on the mechanical and micro structure of polyester composites.

Effect of ZnO on the Thermal Degradation Behavior of Poly(Methyl Methacrylate) Nanocomposites.

The influence of ZnO nanoparticles on the thermal degradation behavior of poly(methyl methacrylate) (PMMA) was tested using thermoanalytical techniques. The studied materials were investigated using TG, DTA, EGA, XRD, SEM and TEM. The ZnO nanoparticles were synthesized via precipitation by adding LiOH into Zn2+ water/ethylene glycol solutions. The ZnO-PMMA nanocomposites were prepared by adding the appropriate amount of ZnO into MMA and subsequent MMA radical polymerization. According to the experimental results and model-free isoconversional activation energy calculations, the addition of ZnO into PMMA played a double role. The ZnO concentrations up to 0.15% stabilized the composite by shifting the degradation interval toward higher temperatures and increasing the apparent activation energy relative to pure PMMA. At higher concentrations, the catalytic effect of ZnO started to prevail and was reflected in the lower temperature intervals of intense PMMA degradation and lower apparent activation energy. The addition of ZnO generally did not change the nature of the PMMA decomposition process.

Influence of ZnO nanoparticles on Coumarin-503 and Coumarin-540 dye mixture for energy transfer distributed feedback dye lasers

Using organic dyes Coumarin-503 (C503) and Coumarin-540 (C540) as donor and acceptor dyes, respectively, and Nd-YAG as pumping source (355 nm), an energy transfer-distributed feedback dye laser (ETDFDL) was constructed and its characteristics studied. Theoretical studies such as critical transfer radius (Ro), critical concentration (Co), and half quenching concentration (C1/2) were carried out using the absorption and fluorescence spectra of donor and acceptor dyes. On varying the input pump energy to the nanoparticle-incorporated ETDFDL and keeping the acceptor and donor dye concentrations constant, the lasing output obtained was found to be higher than that without the use of nanoparticles. This enhancement was due to the size, shape, and coupling between nanoparticles with the dye mixture. Tunability in the range of 435–553 nm was obtained for both donor (C503) and acceptor (C540) DFDL as a function of the angle of interfering beams of the pump laser.