Nano ZnO Research Articles

Fabrication of a fluorine-free photocatalytic superhydrophobic coating and its long-lasting anticorrosion and excellent antibacterial abilities

Superhydrophobic multifunctional coatings have wide application prospects in construction, shipping, transportation equipment and aerospace etc. In this paper, a fluorine-free photocatalytic superhydrophobic coating with long-lasting anticorrosion performance and excellent antibacterial ability has been developed on various substrates by a simple spraying method. The coating is mainly composed of epoxy resin (EP), polydimethylsiloxane (PDMS) and hydrophobically modified micron ZnO (m-ZnO) and nano ZnO (n-ZnO). The coating maintains excellent wettability to various common liquids, and the water contact angle (WCA) and sliding angle (SA) of coating are 162.8° and 3°, respectively. The synergistic effect of the air layers and the coating denseness endows coating with excellent corrosion inhibition efficiency (ηp > 99.9 %) in 3.5 wt% NaCl solution and neutral salt spray tests for 30 days. The photocatalytic activity and superhydrophobicity endow coating with bactericidal activity and antibacterial adhesion properties, thus providing the coating with excellent antibacterial ability in dynamic or static liquid environment. Furthermore, the coating can withstand chemical erosion, ultraviolet radiation and mechanical durability tests such as knife scraping, tape peeling and sandpaper wear cycles. This large-scale fabrication, environmentally benign, low cost and high performance coating has potential practical applications in a wider range of fields.

Synergistic Piezo-Catalytic Inactivation of Bacteria by Dual-Frequency Ultrasound (120 + 1700 kHz) Using Persulfate and ZnO Nano- and Microparticles

Dual-frequency ultrasound (DFUS) coupled with sonocatalysts has emerged to be an advanced tool for antimicrobial applications in medicine but remains scarcely studied for water disinfection. In the present work, we first integrated high-frequency DFUS (120 + 1700 kHz), persulfate (S2O82−) and ZnO nano- (50 nm) and microparticles (1 μm) for eradicating Escherichia coli and Enterococcus faecalis in synthetic water. For E. coli, the efficiency of DFUS-based processes can be ranked as follows: DFUS < DFUS/ZnO < DFUS/S2O82− < DFUS/ZnO/S2O82−. A similar efficiency of the DFUS/S2O82− and DFUS/ZnO/S2O82− processes was found for more resistant E. faecalis. In the absence of persulfate, the performance of 1 μm ZnO was higher than that observed with 50 nm for inactivating E. coli via the DFUS/ZnO and 1700 kHz/ZnO processes. A synergy of DFUS in terms of 5-log (total) reduction was found in the S2O82−/ZnO-based systems, being higher for E. faecalis (synergistic coefficient = 1.8–3.0). The synergistic effect was proposed to be driven by the boosted generation of reactive oxygen species and sonoporation. This study opens prospects for the development of novel DFUS-based piezo-catalytic systems for efficient water disinfection.

Effect of Biocapsule and Nano Micronutrients on Growth, Quality and Yield of Lettuce (Lactuca sativa)

The present experiment was carried out during 2021-22 in Central Horticulture Research Farm of Department of Horticulture, SHUATS, Prayagraj. The experiment was conducted in Randomized Block Design with 10 treatment replicated thrice with an objective to find out best treatment for growth, yield, quality and B:C ratio. The treatments were T0 (Control), T1 (NPK (RDF) 15:5:20),T2 (Biocapsule 500ppm (Soil drenching)),T3 (NPK (RDF) 15:5:20 + Biocapsule 500ppm (Soil drenching)),T4 (NPK (RDF) + Foliar application of Zno (12%) and Feo (12%) Nano particles (NPs)),T5 (Biocapsule 500ppm (Soil drenching) + Foliar application of Zno (12%) and Feo(12%) Nano particles (NPs)),T6 (NPK (RDF) 15:5:20 + Biocapsule 500ppm (Soil drenching) + Foliar application of Zno (12%) and Feo (12%) Nano particles (NPs)),T7 (NPK (RDF) 15:5:20 + Biocapsule 250ppm (Soil drenching)),T8 (Biocapsule 250ppm (Soil drenching) + Foliar application of Zno (12%) and Feo (12%) Nano particles (NPs)),T9 (NPK (RDF) 15:5:20 + Biocapsule 250ppm (Soil drenching) + Foliar application of Zno (12%) and Feo (12%) Nano particles (NPs)). From our experiment it was concluded that the treatment T5 (Biocapsule 500ppm (Soil drenching) + Foliar application of ZnO (12%) and FeO (12%) Nano particles (NPs)) was found to be best in the terms of germination percentage, vegetative growth, yield parameters, quality parameters and economics with Benefit Cost ratio 2.67.

Agronomic Zn biofortification through nano ZnO application enhanced growth, photosystem efficiency, Zn and P nutrition in maize

ABSTRACT Zinc-oxide nanoparticles (ZnO-NP) effect on crop physiology and zinc recovery remains poorly studied for acidic-sandy soils. To address this, greenhouse pot (plastic-pots, 6 kg soil, maize) experiments with ZnO-NP (50, 100, 150, 200 mg kg−1) applied via different methods (soil-drench, seed-coating and foliar-spray) was conducted in a 60 days study. Results revealed that ZnO-NP via seed-coating (100 mg kg−1) and soil-drench (150 mg kg−1) enhanced shoot and total P uptake, while ZnO-NPs (foliar) (50 mg kg−1) enhanced maize growth (6–11%), with agronomic and physiological improvements ultimately resulted in greater biomass (16–20%), Zn agronomic efficiency and uptake. Compared to ZnSO4 treatment and the control, seed-coating with 100 mg kg−1 ZnO-NP increased leaf chlorophyll and pigment content by 12–127%. Principal component analysis revealed a close association among growth traits, plant pigments, fluorescence parameters, total Zn and P concentration, and uptake with total biomass as influenced by ZnO-NPs. Thus, compared to conventional ZnSO4 and higher dosages of ZnO-NPs, foliar-spray of ZnO-NP at 50 mg kg−1, seed-coating at 100 mg kg−1, or soil-drench at 150 mg kg−1 increased maize biochemical characteristics, growth, biomass, and Zn agronomic efficiency. These elucidate important implications of ZnO-NP application for increasing plant development and Zn biofortification in acidic-sandy soils.

Determination of thorium adsorption processes by alpha spectrometry on Co-doped ZnO nano materials; modeling and optimization

Determination of thorium adsorption processes by alpha spectrometry on Co-doped ZnO nano materials; modeling and optimization

New insights into bacterial Zn homeostasis and molecular architecture of the metal resistome in soil polluted with nano zinc oxide

Accumulation of nano ZnO (nZnO) in soils could be toxic to bacterial communities through disruption of Zn homeostasis. Under such conditions, bacterial communities strive to maintain cellular Zn levels by accentuation of appropriate cellular machinery. In this study, soil was exposed to a gradient (50–1000 mg Zn kg-1) of nZnO for evaluating their effects on genes involved in Zn homeostasis (ZHG). The responses were compared with similar levels of its bulk counterpart (bZnO). It was observed that ZnO (as nZnO or bZnO) induced a plethora of influx and efflux transporters as well as metallothioneins (MTs) and metallochaperones mediated by an array of Zn sensitive regulatory proteins. Major influx system identified was the ZnuABC transporter, while important efflux transporters identified were CzcCBA, ZntA, YiiP and the major regulator was Zur. The response of communities was dose- dependent at lower concentrations (<500 mg Zn kg-1 as nZnO or bZnO). However, at 1000 mg Zn kg-1, a size-dependent threshold of gene/gene family abundances was evident. Under nZnO, a poor adaptation to toxicity induced anaerobic conditions due to deployment of major influx and secondary detoxifying systems as well as poor chelation of free Zn ions was evident. Moreover, Zn homeostasis related link with biofilm formation and virulence were accentuated under nZnO than bZnO. While these findings were verified by PCoA and Procrustes analysis, Network analysis and taxa vs ZHG associations also substantiated that a stronger Zn shunting mechanism was induced under nZnO due to higher toxicity. Molecular crosstalks with systems governing Cu and Fe homeostasis were also evident. Expression analysis of important resistance genes by qRT-PCR showed good alignment with the predictive metagenome data, thereby validating our findings. From the study it was evident that the induction of detoxifying and resistant genes was greatly lowered under nZnO, which markedly hampered Zn homeostasis among the soil bacterial communities.

Effect of shape of ZnO nanoparticle on electro-optic and dielectric properties of nematic liquid crystal

Properties of liquid crystal incorporated with various shapes of a nanomaterial are expected to show multifaceted behaviour as properties of nanomaterial are extremely dependent on its size and shape. In view of this, we have investigated the effect of shape of ZnO nanoparticle on electro-optic and dielectric properties of nematic liquid crystal (NLC), PCH5. Nanocomposites of 0.01 wt% ZnO nano- sphere, rods, and wires in NLC are prepared. The addition of ZnO nanoparticles to NLC leads to increase in the order parameter and reduction in threshold voltage, response time as well as ionic conductivity as compared to the pure NLC host. Dielectric permittivity measurements indicate nanoparticle induces short range order in isotropic phase. Dielectric measurements also show increase in order parameter in nanocomposites with 1D nanoparticles whereas negligible change is observed in nanocomposites with spherical nanoparticles in NLC in deep nematic range. The ATR-FTIR measurements support the enhancement in parallel correlation of dipole moments in ZnO nanocomposites as compared to pure NLC.

Electric Field Manipulation of Defects and Schottky Barrier Control inside ZnO Nanowires.

We directly measure the three-dimensional movement of intrinsic point defects driven by applied electric fields inside ZnO nano- and micro-wire metal-semiconductor-metal device structures. Using depth- and spatially resolved cathodoluminescence spectroscopy (CLS) in situ to map the spatial distributions of local defect densities with increasing applied bias, we drive the reversible conversion of metal-ZnO contacts from rectifying to Ohmic and back. These results demonstrate how defect movements systematically determine Ohmic and Schottky barriers to ZnO nano- and microwires and how they can account for the widely reported instability in nanowire transport. Exceeding a characteristic threshold voltage, in situ CLS reveals a current-induced thermal runaway that drives the radial diffusion of defects toward the nanowire free surface, causing VO defects to accumulate at the metal-semiconductor interfaces. In situ post- vs pre-breakdown CLS reveal micrometer-scale wire asperities, which X-ray photoelectron spectroscopy (XPS) finds to have highly oxygen-deficient surface layers that can be attributed to the migration of preexisting VO species. These findings show the importance of in-operando intrinsic point-defect migration during nanoscale electric field measurements in general. This work also demonstrates a novel method for ZnO nanowire refinement and processing.

A passive-chipless LC carbon dioxide sensor with non-contact ZnO/CuO/RGO nanocomposites at room temperature

Metal oxides are one of the hot research directions of sensors. Their low cost, high sensitivity, short response time, short recovery time and other advantages have attracted much attention in the field of gas detection. An RFID carbon dioxide sensor based on ZnO/CuO/RGO nanocomposite layer is proposed, which can respond quickly. The ZnO nano materials we prepared by hydrothermal method are rod materials with high specific surface area, and the nano CuO is petal shaped. The heterojunction formed by the two increases the gas adsorption sites, reduces the activation energy when reacting with carbon dioxide, and is also highly sensitive to carbon dioxide at room temperature. Then we use the reduced graphene oxide to change its physical properties and improve the conductivity of semiconductor materials. The sensor determines the amplitude of carbon dioxide concentrationAt room temperature, the amplitude of the sensor varies from −24.0 dB to −13.0 dB. The sensor can quickly respond to and recover from the carbon dioxide concentration of 500 ppm–1600 ppm, and the recovery time varies from 30s to 60s. Compared with the traditional carbon dioxide sensor which needs higher working temperature, this paper designs a carbon dioxide sensor. This RFID carbon dioxide sensor has good temperature adaptability, reversibility, repeatability, low cost and other characteristics, and can be widely used in fruit and vegetable storage, transportation, agricultural greenhouses, indoor environmental monitoring and other fields.

Investigation on structural, optical and electrical properties of BiFeO3:ZnO nano–micro particles–matrix composite

A new class of materials called matrix-nano composites has the ability to meet the needs of modern advanced applications and technology. To prepare the BiFeO3:ZnO composite, BiFeO3 nanoparticles were prepared using a low–cost sol–gel method, to which ZnO in its micron-sized form was added in varying concentrations of 5%, 10%, and 15%. The structural, morphological, and optical properties of the pure and composite materials were characterized using XRD, FESEM, EDAX, PL spectra, and UV-Visible spectroscopy. The dielectric properties of the pristine and composites were investigated at room temperature. The a.c. conductivity fit with Jonscher's power law and CBH model described the charge conduction behaviour in all pure and composite materials. The temperature-dependent dielectric and loss measurements showed a temperature dependent relaxation process. UV–vis and PL characterization show that the composite materials exhibited improved charge separation efficiency and wider band gaps with increasing BFO content.

Soil polluted with nano ZnO reveals unstable bacterial communities and decoupling of taxonomic and functional diversities

Due to relentless production and disposal of nano zinc oxide (nZnO), it has become critical to comprehend the serious risks large-scale accumulation of nZnO pose to bacterial communities in soil. The primary objective was to evaluate the changes in bacterial community structure and associated functional pathways through predictive metagenomic profiling and subsequent validation through Quantitative Realtime PCR in soil spiked with nZnO (0, 50, 200, 500 and 1000 mg Zn kg−1) and similar levels of bulk ZnO (bZnO). The results revealed that soil microbial biomass-C, -N, -P, soil respiration and enzyme activities decreased markedly at higher ZnO levels. The alpha diversity decreased with increasing ZnO level, with more impact under nZnO, while beta diversity analyses indicated a distinct dose- dependent separation of bacterial communities. The dominant taxa including Proteobacteria, Bacterioidetes, Acidobacteria and Planctomycetes significantly increased in abundance, while Firmicutes, Actinobacteria and Chloroflexi decreased in abundance with elevated nZnO and bZnO levels. Redundancy analysis indicated that changes in bacterial community structure instilled a greater dose- rather than size- specific response on key microbial parameters. Predicted key functions did not show a dose- specific response, and at 1000 mg Zn kg−1, methane metabolism as well as starch and sucrose metabolism were attenuated, while functions involving two component systems and bacterial secretion systems were enhanced under bZnO indicating better stress avoidance mechanism than under nZnO. Realtime PCR and microbial endpoint assays confirmed the metagenome derived taxonomic and functional data, respectively. Taxa and functions that varied substantially under stress were established as bioindicators to predict nZnO toxicity in soils. Taxon-function decoupling indicated that the soil bacterial communities deployed adaptive mechanisms under high ZnO, with lesser buffering capacity and resilience of communities under nZnO.

Biopolymer Based Multifunctional Films Loaded with Anthocyanin Rich Floral Extract and ZnO Nano Particles for Smart Packaging and Wound Healing Applications.

There are significant societal repercussions from our excessive use of plastic products derived from petroleum. In response to the increasing environmental implications of plastic wastes, biodegradable materials have been proven to be an effective means of mitigating environmental issues. Therefore, protein- and polysaccharide-based polymers have gained widespread attention recently. In our study, for increasing the strength of a biopolymer (Starch), we used ZnO dispersed nanoparticles (NPs), which resulted in the enhancement of other functional properties of the polymer. The synthesized NPs were characterized using SEM, XRD, and Zeta potential values. The preparation techniques are completely green, with no hazardous chemicals employed. The floral extract employed in this study is Torenia fournieri (TFE), which is prepared using a mixture of ethanol and water and possesses diverse bioactive features and pH-sensitive characteristics. The prepared films were characterized using SEM, XRD, FTIR, contact angle and TGA. The incorporation of TFE and ZnO (SEZ) NPs was found to increase the overall nature of the control film. The results obtained from this study confirmed that the developed material is suitable for wound healing and can also be used as a smart packaging material.

Effect of Nano Zinc Oxide Seed Treatment on Physiological Growth and Biophysical Traits and Seed Quality of Soybean [Glycine max (L.) Merrill

The field experiment was conducted at Seed Technology Research Center, Department of Plant breeding and Genetics, JNKVV-Jabalpur Kharif-2021. Growth analytical attributes studies indicated superior performance of seed treatment with nano-ZnO @500mg L-1 for LAI @60 DAS (days after sowing), @70 DAS, @80 DAS, LAD, CGR, RGR and BMD w.r.t. 24.26%, 21.39%, 28.50%, 12.09%, 21.42%, 20.17% and 20.56% enhancement over control. Varietal studies revealed superior performance of variety JS 20-116 for LAI, LAD, CGR, RGR and BMD. Biophysical parameters studies revealed superior performance of seed treatment with nano –ZnO @500mg L-1 for chlorophyll content index and energy interception with 5.19% and 26.51% enhancement over control respectively. With respect to variety superior performance of variety JS-20-116 for chlorophyll content index and energy interception. Seed quality parameters studies indicated superior performance of seed treatment with nano–ZnO @500mg L-1 for final plant stand, germination, and seed vigour index I and seed vigour index II with respect to 29.16%, 14.11%, 26.40% and 21.43% enhancement over control. With respect to variety, superior performance of variety JS-20-116 for final plant stand, and seed vigour index I and seed vigour index II and JS 20-34 for seed germination. This results justifies that the seed treatment with nano formulation in the form of ZnO @ 500mg L-1 will improve growth analytical attributes, physiological efficiency and seed quality of the soybean. Hence the seed treatment with nano-ZnO @500mg L-1 is recommended to farmers for maximum productivity, physiological efficiency and sowing seed quality.

Integrated use of plant growth-promoting bacteria and nano-zinc foliar spray is a sustainable approach for wheat biofortification, yield, and zinc use efficiency.

The intensive cropping system and imbalance use of chemical fertilizers to pursue high grain production and feed the fast-growing global population has disturbed agricultural sustainability and nutritional security. Understanding micronutrient fertilizer management especially zinc (Zn) through foliar application is a crucial agronomic approach that could improve agronomic biofortification of staple grain crops. The use of plant growth-promoting bacteria (PGPBs) is considered as one of the sustainable and safe strategies that could improve nutrient acquisition and uptake in edible tissues of wheat to combat Zn malnutrition and hidden hunger in humans. Therefore, the objective of this study was to evaluate the best-performing PGPB inoculants in combination with nano-Zn foliar application on the growth, grain yield, and concentration of Zn in shoots and grains, Zn use efficiencies, and estimated Zn intake under wheat cultivation in the tropical savannah of Brazil. The treatments consisted of four PGPB inoculations (without inoculation, Azospirillum brasilense, Bacillus subtilis, and Pseudomonas fluorescens, applied by seeds) and five Zn doses (0, 0.75, 1.5, 3, and 6 kg ha-1, applied from nano ZnO in two splits by leaf). Inoculation of B. subtilis and P. fluorescens in combination with 1.5 kg ha-1 foliar nano-Zn fertilization increased the concentration of Zn, nitrogen, and phosphorus in the shoot and grain of wheat in the 2019 and 2020 cropping seasons. Shoot dry matter was increased by 5.3% and 5.4% with the inoculation of P. fluorescens, which was statistically not different from the treatments with inoculation of B. subtilis as compared to control. The grain yield of wheat was increased with increasing nano-Zn foliar application up to 5 kg Zn ha-1 with the inoculation of A. brasilense in 2019, and foliar nano-Zn up to a dose of 1.5 kg ha-1 along with the inoculation of P. fluorescens in the 2020 cropping season. The zinc partitioning index was increased with increasing nano Zn application up to 3 kg ha-1 along with the inoculation of P. fluorescens. Zinc use efficiency and applied Zn recovery were improved at low doses of nano-Zn application in combination with the inoculation of A. brasilense, B. subtilis, and P. fluorescens, respectively, as compared to control. Therefore, inoculation with B. subtilis and P. fluorescens along with foliar nano-Zn application is considered a sustainable and environmentally safe strategy to increase nutrition, growth, productivity, and Zn biofortification of wheat in tropical savannah.

Graphene oxide synthesis methods based on electrochemical exfoliation pencil core

Graphene oxide (GO) was produced by using electrochemical exfoliation of pencil core (6B, 8 mm diameter). Ammonium sulphate (0.1 M) was used as an electrolyte solution. The two electrodes were placed in parallel at a distance of 5 cm. while the supply voltage was fixed at 8 V DC for 10 min. A floating layer of graphene on top of the bath was collected for cleaning process. A graphene oxide (GO) product was characterized by using Raman spectroscopy, UV–vis spectroscopy and Scanning Electron Microscopy-Energy Dispersive X-Ray (SEM-EDX). ZnO powder synthesized by hydrothermal process was mixed with graphene oxide according to different weight percentage concentrations. ZnO:GO composite paste was coating on FTO glass substrate by the drop casting method. The SEM result indicates that the graphene oxide was embedded around ZnO nano spheres.

Facile hydrothermal synthesis of ZnO nanoparticles on silicalite-1: Effect of ultra ZnO Nano size on desulfurization activities

Reactive adsorption desulphurization (RADS) is an excellent technique for producing ultra-clean sulphur-free fuel in mild operating conditions. The sulphur adsorption capacities of the catalysts strongly relate to the stable nano size of ZnO nanoparticles, dispersion of active phases, and the acidity of the catalysts. In this work, a series of ultra nano-sized ZnO nanoparticles with a nano-size of 2–8 nm supported on silicalite-1 were synthesized via a homogeneous hydrothermal technique and utilized as a support for the dispersion of Ni nanoparticles. The RADS activity of the NiZnS-1 catalyst for thiophenic compound substantially increased from 163 mg S/g to 205 mg S/g with the decrease of the ZnO particle size from 8 nm to 2 nm. The NiZnS-1 adsorbents were characterized through N2 adsorption-desorption, Raman spectroscopy, X-ray diffraction, High-resolution transmission electron microscopy, and Temperature-programmed desorption of ammonia. Catalytic activity tests show that NiZnS-1(6) adsorbent with ZnO particle size of 2–3 nm achieved an excellent breakthrough sulphur adsorption capacity of 57.5mgS/g and accumulative sulphur adsorption capacities of 205 mg S/g while dealing with model gasoline (1500 mg/L). Which is four folds higher than NiZnS-1(20) adsorbent with a compromised RADS capacity of 163 mg S/g. This superior desulphurization activity and sulphur adsorption capacity for NiZnS-1 adsorbent strongly depend on to the size of ZnO nanoparticles, the diffusion rate of the reactant’ and product molecules, the adsorbent total acidity and ZnO/Ni nanoparticles dispersion on the support. Upon five desulfurization regeneration cycles, NiZnS-1 showed high stability without apparent activity loss, revealing that the ZnO particle size is intact after multiple cycles. A mechanism is proposed based on the desulphurization results.

Application and enhancement effect of nano-ZnO film preparation technology in the protection of paper artwork

Nano-ZnO has the characteristics of photocatalytic performance and excellent transparency and conductivity. Because of its many excellent properties, it also occupies a very important position in the types of semiconductor materials. Nano-ZnO film preparation technology has been researched and developed and applied in many fields, but there are few applied researches on the protection of paper artworks. The main content of this article is the study of the application and enhancement effect of nano-ZnO film preparation technology on the protection of paper cultural relics. In this paper, the sol-gel process is selected in the common film preparation process, and the configured sol is dipped and lifted. By comparing the paper covered with nano ZnO film and the paper not covered with nano ZnO film in the anti-aging performance test, anti-ultraviolet aging performance test, aging appearance change and the experimental results of the mechanical performance test of the application effect of different papers, the results are investigated. The application and enhancement effect of nano-ZnO film preparation technology in the protection of paper art works. Experimental studies have shown that under the same aging time, the mechanical properties of rice paper covered with nano-Zno film are higher than those of blank rice paper without nano-Zno film. The transverse tensile strength of the paper is increased by 5.88 m/N, an increase of 98%. The vertical tensile strength increased by 3.93 m/N, an increase of about 87%, the vertical folding resistance increased by 16 times, the horizontal folding resistance increased by 15 times, and the vertical tearing strength increased by 4.15 m/N, an increase of about 125%, and the transverse tearing degree is enhanced by 2.21 m/N, which is about 64%. The two kinds of rice paper were subjected to warm-heat aging, and the final results showed that the mechanical properties of the two kinds of rice papers showed a decreasing trend, but the mechanical properties of the rice paper covered by the nano-Zno film decreased at a slower rate, and the final mechanical properties were also lower than that of untreated rice paper. Blank rice paper covered with film is better. The experimental results of ultraviolet light on paper aging show that the nano-Zno film covering the paper will delay the paper aging, and the appearance of the nano-Zno film after ultraviolet light does not change significantly. Under the mechanical performance test of nano Zno film on different types of paper application, the tensile strength, folding resistance and tearing degree of the three papers participating in the experiment have been improved, which shows that the nano Zno film has the advantage of strengthening paper.

An alternative ZnO with large specific surface area: Preparation, physicochemical characterization and effects on growth performance, diarrhea, zinc metabolism and gut barrier function of weaning piglets

High-dose ZnO is widely used to prevent diarrhea and promote growth of weaning piglets, which has led to serious problems of animal toxicity, bacterial resistance and environmental pollution. In this study, a novel alternative ZnO (AZO) was prepared and its physicochemical properties were characterized. Animal experiments were further conducted to evaluate the effects of the ZnO forms, the dose of AZO and the combinations with AZO on the growth performance, diarrhea, zinc metabolism and gut barrier function of weaning piglets. The results showed that the AZO, compared with ordinary ZnO (OZO), nano ZnO (NZO) and porous ZnO (PZO), had the largest surface area and reduced the release of Zn2+ into the gastric fluid. AZO showed better antibacterial activity on Escherichia coli K88, Staphylococcus aureus and Salmonella enteritidis but lower cytotoxicity on porcine intestinal epithelial cells. Animal experiments suggested that low-dose AZO, NZO and PZO (300 mg/kg) improved growth performance and reduced diarrhea in weaning piglets as well as high-dose OZO (3000 mg/kg). Notably, low-dose AZO had the lowest diarrhea incidence. Additionally, low-dose AZO in combination with probiotics improved digestibility and digestive enzyme activities. Low-dose AZO in combination with probiotics also upregulated the expression of the intestinal zinc transporter proteins ZIP4 and DMT1, increased zinc bioavailability, reduced faecal zinc emissions, and avoided zinc overload in the liver and oxidative damage caused by high-dose ZnO. Moreover, low-dose AZO in combination with probiotics improved the gut barrier function of weaning piglets by promoting the expression of tight junction proteins, mucins and antimicrobial peptides and increasing gut microbiota diversity and beneficial Lactobacillus. This study proposed a novel strategy to replace high-dose ZnO and antibiotics with low-dose AZO and probiotics in weaning piglets, which effectively improved growth performance and prevented diarrhea while reducing animal toxicity, bacterial resistance, heavy metal residues and zinc emission pollution.

ZnO-PLLA/PLLA Preparation and Application in Air Filtration by Electrospinning Technology.

With the increasing environmental pollution caused by disposable masks, it is crucial to develop new degradable filtration materials for medical masks. ZnO-PLLA/PLLA (L-lactide) copolymers prepared from nano ZnO and L-lactide were used to prepare fiber films for air filtration by electrospinning technology. Structural characterization of ZnO-PLLA by H-NMR, XPS, and XRD demonstrated that ZnO was successfully grafted onto PLLA. An L9(43) standard orthogonal array was employed to evaluate the effects of the ZnO-PLLA concentration, ZnO-PLLA/PLLA content, DCM(dichloromethane) to DMF(N,N-dimethylformamide) ratio, and spinning time on the air filtration capacity of ZnO-PLLA/PLLA nanofiber films. It is noteworthy that the introduction of ZnO is important for the enhancement of the quality factor (QF). The optimal group obtained was sample No. 7, where the QF was 0.1403 Pa-1, the particle filtration efficiency (PFE) was 98.3%, the bacteria filtration efficiency (BFE) was 98.42%, and the airflow resistance (Δp) was 29.2 Pa. Therefore, the as-prepared ZnO-PLLA/PLLA film has potential for the development of degradable masks.

Tuning electrical heterogeneity in CaCu3Ti4O12-ZnO ceramics for high dielectric and nonlinear properties

Tuning the electrical heterogeneity of CaCu3Ti4O12 (CCTO) ceramic is extremely important to improve its properties. In this work, the CCTO ceramics with enhanced dielectric and nonlinear properties were obtained by the introduction of nano ZnO based on the electrical heterogeneity modulation strategy. As a result, all the CCTO-ZnO samples show the colossal dielectric constant of 104–105 at room temperature. Meanwhile, the dielectric constant of CCTO-ZnO samples exhibits better stability in a wide frequency range from 101 Hz to 105 Hz and over a temperature scope of 30–210 °C. Most importantly, the x = 0.04 sample presents a relatively lower room-temperature dielectric loss of about 0.07 at 103 Hz. Furthermore, the breakdown field strength accompanied by the nonlinear coefficient of CCTO-ZnO ceramics is also improved. The enhancement of dielectric and nonlinear behaviors in these ceramics is mainly ascribed to the tunable electrical heterogeneity as per the internal barrier layer capacitor (IBLC) model.