ZnO Chitosan Research Articles

Introducing the antibacterial and photocatalytic degradation potentials of biosynthesized chitosan, chitosan–ZnO, and chitosan–ZnO/PVP nanoparticles

The development of nanomaterials has been speedily established in recent years, yet nanoparticles synthesized by traditional methods suffer unacceptable toxicity and the sustainability of the procedure for synthesizing such nanoparticles is inadequate. Consequently, green biosynthesis, which employs biopolymers, is gaining attraction as an environmentally sound alternative to less sustainable approaches. Chitosan-encapsulated nanoparticles exhibit exceptional antibacterial properties, offering a wide range of uses. Chitosan, obtained from shrimp shells, aided in the environmentally friendly synthesis of high-purity zinc oxide nanoparticles (ZnO NPs) with desirable features such as the extraction yield (41%), the deacetylation (88%), and the crystallinity index (74.54%). The particle size of ZnO NPs was 12 nm, while that of chitosan–ZnO NPs was 21 nm, and the bandgap energies of these nanomaterials were 3.98 and 3.48, respectively. The strong antibacterial action was demonstrated by ZnO NPs, chitosan–ZnO NPs, and chitosan–ZnO/PVP, particularly against Gram-positive bacteria, making them appropriate for therapeutic use. The photocatalytic degradation abilities were also assessed for all nanoparticles. At a concentration of 6 × 10–5 M, chitosan removed 90.5% of the methylene blue (MB) dye, ZnO NPs removed 97.4%, chitosan-coated ZnO NPs removed 99.6%, while chitosan–ZnO/PVP removed 100%. In the case of toluidine blue (TB), at a concentration of 4 × 10–3 M, the respective efficiencies were 96.8%, 96.8%, 99.5%, and 100%, respectively. Evaluation of radical scavenger activity revealed increased scavenging of ABTS and DPPH radicals by chitosan–ZnO/PVP compared to individual zinc oxide or chitosan–ZnO, where the IC50 results were 0.059, 0.092, 0.079 mg/mL, respectively, in the ABTS test, and 0.095, 0.083, 0.061, and 0.064 mg/mL in the DPPH test, respectively. Moreover, in silico toxicity studies were conducted to predict the organ-specific toxicity through ProTox II software. The obtained results suggest the probable safety and the absence of organ-specific toxicity with all the tested samples.

Distinct effects of dietary chitosan, ZnO, and chitosan–ZnO nanocomposite on the performance and diet economic efficiency of Pacific white shrimp (Penaeus vannamei)

Distinct effects of dietary chitosan, ZnO, and chitosan–ZnO nanocomposite on the performance and diet economic efficiency of Pacific white shrimp (Penaeus vannamei)

A Study on the Photocatalytic and Antimicrobial Activities of Chitosan–ZnO Nanocomposites

ZnO nanoparticles can have their size, crystalline phase and aggregation inhibited by the biocompatible polymer chitosan. The production of ZnO nanoparticles with chitosan assistance was carried out using Sol-gel methodology. The nanoparticles have been studied using XRD, TGA, Surface analysis and HR-TEM. According to the findings, ZnO nanoparticles have a hexagonal shape and a particle size of roughly 91 nm. The synthesized nanoparticles exhibit improved photocatalytic activity for reactive dyes for Congo red when exposed to sunlight. The Langmuir-Hinshelwood (L-H) model revealed that the kinetics followed a pseudo-first-order. Additionally, the antibacterial activity was tested against the gram-negative Escherichia coli bacteria.

Fabrication of ZnO decorated porous chitosan beads for the sustainable bioremediation of Cr(VI) contaminated water

Chromium contamination, particularly in industrial and mining sectors, has become a serious issue for the aquatic system, globally. Until now, the removal of Cr(VI) have been accomplished by a variety of approaches. However, these existing techniques are economically not efficient. Here, we demonstrate quick and effective removal of Cr(VI) from water by biosorption method using simple polymer modification technique. Specifically, we synthesized native chitosan beads (NCB) and ZnO NPs modified chitosan beads (ZMCB) for the adsorptive elimination of Cr(VI) from aqueous medium. Some advanced analytical techniques such as BET, SEM-EDX, XRD and FTIR were applied to characterize the biosorbents. Both NCB and ZMCB followed Langmuir isotherm model and maximum adsorption capacity of 23.16 mg/g and 130.28 mg/g, respectively was observed at optimal conditions (1.5 g dose, pH 2, initial concentration 50 ppm at 293 K). The results showed that pseudo 2nd order (PSO) kinetic was best fitted for the biosorption process, as coefficient regression constant for PSO have highest value (R2 > 0.999). Additionally, it was observed that the ZMCB composite may be used in many Cr(VI) adsorption cycles with little decrease in adsorption efficiency (91% adsorption up to the 5th cycle). Overall, this study offers a quick and easy approach for synthesizing low-cost materials that will be extremely useful for environmental applications.

Development of ZnO/selenium nanoparticles embedded chitosan-based anti-bacterial wound dressing for potential healing ability and nursing care after paediatric fracture surgery.

The current study was aimed at the assessment of the effect of chitosan-ZnO/Selenium nanoparticles scaffold on infected wound healing and care of paediatric surgery treatment. The nanoparticle scaffolds were developed from sources such as chitosan (CS), different concentrations of zinc oxide (ZnO), and Selenium (SeNPs) nanoparticles by freeze-drying method. The structural and chemical properties of nanoparticles were investigated by UV-Vis, fourier transform infrared spectroscopy (FTIR), and phase identification by x-ray diffraction analysis. The surface morphology of CS, chitosan-ZnO (CS-ZnO) and chitosan-ZnO/SeNPs was analysed using a scanning electron microscope. The incorporation of ZnO and SeNPs along with CS polymer induces antioxidant and antimicrobial functions. The bacterial susceptibility to nanoparticle scaffolds against Escherichia coli and Staphylococcus aureus showed the excellent antibacterial effects of ZnO and SeNPs. In-vitro studies of fibroblast of NIH 3T3 and HaCaT cell lines revealed the biocompatibility, cell adhesion, cell viability, and proliferation of scaffold in the wound site. Also, results of in-vivo studies strongly enhanced collagen synthesis, re-epithelialization, and rapid wound closure. Thus, the synthesised chitosan-ZnO/SeNPs nanoparticle scaffold resulted in significant improvement in histopathological indices in the full thickness of wound healing after nursing care of paediatric fracture surgery.

Preparation, characterization, and antibacterial effect of bio-based modified starch films

There are several problems with common starch films, including strong water absorption and poor mechanical properties. To create a better starch film, octenyl succinate cassava starch ester (OSCS) was first blended with chitosan and nano ZnO to prepare an OSCS/CS/ZnO film. Then, the film was supplemented with different concentrations of ε-PL as a bacteriostatic agent to prepare a film that would resist bacterial invasion. The mechanical properties, barrier properties, optical properties, and color of the modified starch antibacterial films were investigated, and finally the antibacterial properties and cytotoxicity were tested. The results demonstrated that the modified starch antibacterial film had good mechanical properties, improved surface hydrophobicity, and had a UV-blocking effect. The modified starch antibacterial film with ε-PL of 8% had stable and long-lasting antibacterial properties, stable release, and good cytocompatibility. An active packaging material was successfully prepared using ε-PL and had a strong preservative effect on food.

Design and characterization of an antibacterial film composited by hydroxyethyl cellulose (HEC), carboxymethyl chitosan (CMCS), and nano ZnO for food packaging

For food packaging, a novel composite film was prepared by solution casting method using hydroxyethyl cellulose (HEC), carboxymethyl chitosan (CMCS), and zinc oxide nanoparticles as raw materials. The composite film successfully compounded the nanoparticles, as deduced by spectroscopy, crystallography and morphology observation. The addition of CMCS and ZnO enhanced the solvent resistance (the water solubility of the composite film was reduced by 94.3 %) and UV shielding ability (the UV shielding capacity of the composite film was increased by 45.73 %) of the composite film, thus improving the application prospects of the composite film in water-rich foods. In addition, the synergistic effect of CMCS and ZnO helped the composite film to efficiently inhibit the pathogenic bacteria Listeria monocytogenes and Pseudomonas aeruginosa (rate of inhibition>99.99 %) in food. The addition of CMCS and ZnO also significantly improved the elasticity (improve 494.34 %) and maximum load capacity (improve 142.24 %) of the composite film.

Nanochemistry: A Multidisplinary Approach towards Innovations in Agriculture Soils and Improved Yields

Agriculture has made significant strides recently, and sustainability build on those successes by using a smart strategy that may maintain greater returns and farm profitability without depleting the resources. Furthermore, nano-materials enhance the efficiency of farm production to enable site targeted regulated distribution of minerals, assuring the least amount of agri-input usage while enhancing crop output. Particularly in the agriculture industry, nanoscienceis crucial for agricultural production, food packaging and processing, water purification, nutrition security, and pollution control as well as crop development and plant preservation. NPs display a well-organized antibacterial activity towards bacteria and viruses. Important inorganic NPs with effective pesticide characteristics include silver, aluminum and copper. Chitosan nano-particles, ZnO nano-particles, and silica nano-particles are beneficial for the treatment of virus infection, including the mosaic virus in tobacco, potatoes, and alfalfa. The revitalization of the damaged soil resources may be possible using nano-enabled soil rehabilitation. The toxicity copper in soil is typically linked to soluble free metal ion species like Cu2+, that are easily accessible and extremely hazardous, in traditional forms of higher soil.

Synthesis, Characterization and Sorption Properties of Biochar, Chitosan and ZnO-Based Binary Composites towards a Cationic Dye

Industrial effluents contaminated with different types of organic dyes have become a major concern to environmentalists due to the carcinogenic nature of the dyes, which are harmful to human and aquatic life. In recent years, the treatment of contaminated effluents by natural resources has been proposed as the most sustainable solution for this problem. In this work, Moringa oleifera (M. oleifera) seed-derived biochar composites, e.g., Biochar-Chitosan (BC), Biochar-ZnO (BZ), and Chitosan-ZnO (CZ) were produced and characterized. The synthesized materials were then utilized to adsorb a cationic dye, methylene blue. Spectroscopic analysis of the biochar-based composites revealed that the modification of biochar by chitosan and ZnO introduced different functional and active groups in the biochar surface. Pore development in the structure of biochar nanocomposites was visible in surface morphological images. The derived biochar was fully amorphous and increased crystallinity by the ZnO modification. The obtained surface area varied from 0.90 ± 0.00 to 14.48 ± 1.13 m2 g−1 for prepared sorbents, where BZ corresponds to the highest and BC corresponds to the lowest surface area, respectively. The basic pH (9) was the most favorable condition for sorption. The sorption reached equilibrium at 90 min. Isotherm revealed the favorability of the Langmuir model over the Freundlich and Temkin models. The highest sorption capacity (~170 mg/g) was found for BC. The BC and BZ showed a 75% increase and 16% decrease in removal due to the chitosan and ZnO modification, respectively. Response surface methodology (RSM) optimization for BC showed similar results to the analytical experiments. The characterization and experimental results prefigure the chemical functionalities as the critical parameter over the surface area for the adsorption process.

Chitosan-ZnO decorated Moringa oleifera seed biochar for sequestration of methylene blue: Isotherms, kinetics, and response surface analysis

The biochar adsorption process is very efficient in the treatment of wastewater treatment. In this study, Moringa oleifera seeds-derived biochar (B) was modified using chitosan-ZnO (CZ), denoted as CZ-B, applied for the removal of methylene blue (MB) dye in an aqueous solution. The biochars were characterized using spectroscopic, Scanning electron microscope (SEM) and X-ray diffraction (XRD) techniques. Response surface methodology (RSM) was applied to explore the impact of time, concentration, and pH on the sorption of MB. The surface functional groups, e.g., hydroxyls, nitriles, carbonyls, carboxylic, ester, and phenol structures were enhanced as observed from spectroscopic results. The irregular porous surface of biochar, the uniform orientation of spherical-shaped CZ particles, and agglomerated chunks of porous rock in CZ-B particles were identified from SEM analysis. XRD patterns indicated a fully amorphous structure of biochar, whereas crystallinity introduced in the CZ-B structure by incorporating CZ was observed. At pH 8, the sorption of MB on all the sorbents was maximum. MB removal efficiency (% R) of biochar, CZ, and CZ-B were 44 %, 47 % and 89.7 %, respectively. The CZ incorporation has increased the MB removal efficiency by ∼104 %. Biochar preferred pseudo-second-order and intraparticle diffusion models, indicating a dual mechanism of chemisorption and pore diffusion, whereas CZ-B followed the pseudo-2nd-order model. Biochar and CZ followed Langmuir isotherm with sorption capacity of 55.10 and 55.85 mg/g, respectively; the Freundlich model explained the sorption isotherm of CZ-B with 135.20 mg/g sorption capacity. RSM analysis for CZ-B revealed that experimental results were best fitted (R2 = 0.9729) into a quadratic 2nd-order polynomial model. The correlation of the actual to the predicted value indicated a reasonable response estimation. Therefore, with the optimization of process parameters, CZ-B can be applied as an efficient sorbent to eliminate organic dyes.Main findings of the work: Modification of M. oleifera seed-originated biochar by chitosan-ZnO composite results in an excellent ternary composite with enhanced sorption properties against organic dye, methylene blue (MB).

Antimicrobial activity of chitosan/ZnO blended coating on silk fabric against Escherichia coli

Antimicrobial coated fabrics have a wide spectrum of use in grooming, biomedical and water purification applications. In this work, we report the antimicrobial property of a nano blend prepared from crab-shell based chitosan and nano ZnO and dip-coated on a silk fabric sample. All the synthesized materials were subjected to FT-IR, XRD and TGA studies to assess the functionality, crystallinity and thermal stability. Deacetylation of chitin to chitosan was revealed by the decrease in the intensity of the acetyl group peak at 1641 cm-1 in chitosan. The crystallite size of the synthesized nano ZnO was found be 15 nm from XRD analysis. Appearance of the characteristics peaks of chitosan (9.58°, 19.98°) and ZnO (31.86°, 34.71°, 36.44°, 56.65°, 62.99° and 68.02°) together in XRD pattern of the blended sample confirmed the blending of chitosan and nano ZnO. The deposition of the nanoblend on the coated silk fabrics was shown by SEM analysis. An inhibition zone of 3mm around the nanoblend coated silk fabric sample against E. coli bacteria clearly indicated that synthesized chitosan/ZnO nanoblend possessed good antibacterial activity.

COD adsorption and optimization from produced water using chitosan–ZnO nanocomposite

COD adsorption and optimization from produced water using chitosan–ZnO nanocomposite

Nano-bio finishing of cotton fabric with quaternized chitosan Schiff base-TiO2-ZnO nanocomposites for antimicrobial and UV protection applications

The purpose of this work is to offer a novel approach to designing multifunctional technical cotton textiles by coating them with smart bio-materials. Two different ternary nanocomposites (NC1, NC2) comprising (ammonium-salicylidene) chitosan Schiff base (ASCSB), TiO2, and ZnO nanoparticles were in-situ prepared and applied for treating cotton fibers using the facile pad-dry-cure process to impart antimicrobial and ultraviolet protection characteristics. Notably, NC1 is TiO2-rich, while NC2 is rich in ZnO. The physicochemical and visual characteristics of the new nanocomposites and the treated fabrics were investigated by spectral, microscopic, and thermal methods. The as-prepared NC1 exhibited a more homogeneous distribution, higher depositing density and smaller mean nanoparticle size (48 nm) when compared to NC2 (56 nm). In contrast, NC2-treated fabrics showed a higher depositing density of nanoparticles than NC1-treated ones. The treated cotton fibers demonstrated strong and sustainable antimicrobial impacts on S. aureus, E. coli, and C. albicans pathogens, with more effective performance for NC2-treated textiles in comparison to NC1-treated fabrics. The NC2-remediated cotton fabrics demonstrated a higher UV protection factor (UPF) value (53) as compared to NC1-coated fabrics (35), indicating that the ZnO-rich nanocomposite endowed cotton fabrics with more ultraviolet protection than TiO2-rich nanocomposite.

Electrospun ZnO-loaded chitosan/PCL bilayer membranes with spatially designed structure for accelerated wound healing

A multifunctional bilayer membrane with electrospinning chitosan (CS) and active ZnO nanoparticles was designed. The outer-layer was constructed with ZnO-encapsulated poly(ε-caprolactone) (PCL) ultrafine fibers in a randomly-orientated structure, which could impart the bilayer membrane with great antibacterial activity. The inner-layer was composed with CS fibers with aligned core-shell structure, which could provide anti-inflammatory and effective cell contact guide function. The structure, morphology and crystallization behavior of the bilayer membrane was investigated by FTIR, TEM, SEM and XRD. Importantly, the bi-layered CS/PCL electrospun membrane loading 1.2 wt% ZnO nanoparticles exhibited an enhanced tensile strength and an obvious inhibitory zone against E. coli and S. aureus, and also presented a non-cytotoxic behavior to fibroblasts. Moreover, the as-prepared bi-layered membrane enabled the maintenance of high bioavailability of ZnO nanoparticles and synchronization with the aligned structural feature of CS fibers, which alleviated inflammation, stimulated cellular migration and re-epithelialization in vivo.

Preparation, characterisation and antibacterial properties of thermoplastic chitosan/nano ZnO composites

ABSTRACT This study prepares thermoplastic chitosan/nano ZnO (CZ) composites by thermomechanical treatment in an internal mixer. Dilute hydrochloric acid aqueous solution is used as the destructuring agent of chitosan and solvent of nano ZnO. Fourier transform infrared spectroscopy and scanning electron microscopy confirm the chitosan–ZnO interaction. The crystallinity and UV transmittance of the composites decreases, while their thermal stability increases due to the addition of nano ZnO. The antibacterial activity of the CZ composites is examined in terms of their inhibitory and bactericidal effects against Escherichia coli, Staphylococcus aureus, and Bacillus subtilis. Improved antibacterial properties are obtained for the CZ composites, compared to pure chitosan sheet. Gram-positive bacteria (S. aureus and B. subtilis) are more sensitive to the antibacterial activity of the CZ composites than Gram-negative bacteria (E. coli). This work provides a simple method to prepare chitosan-based materials and obtains CZ composites with improved antibacterial activities, which can be applied in agriculture and food safety.

Biocidal and biocompatible hybrid nanomaterials from biomolecule chitosan, alginate and ZnO

Biocidal activity and biocompatibility of nanomaterials (NMs) are crucial for healthcare applications. This study aims to develop biocidal hybrid NMs with high inhibition rates to control multidrug-resistant bacterial infection compared to conventional antibiotics. Herein, ZnO, chitosan-ZnO (CZnO) and alginate-ZnO (AZnO) NMs were synthesized via a simple one-pot technique. The one-pot process facilitates the efficiency of a chemical reaction whereby a reactant is subjected to successive chemical reactions in just one step. The resulted NMs bio-physicochemical features were analyzed using various analytical methods. The bactericidal and bacteriostatic mechanism of NMs strongly depends on the production of reactive oxygen species in NMs, due to their size, large surface areas, oxygen vacancies, ion release, and diffusion ability. The antibacterial potential of the NMs was tested against methicillin-resistant Staphylococcus aureus. The inhibition zone disclosed that the AZnO possessed an excellent antibacterial activity compared to ZnO and CZnO. Furthermore, toxicity studies revealed that the AZnO demonstrated low toxicity to the HepG2 cell lines. These results confirmed that the AZnO hybrid nanomaterials are promising futuristic biocidal agents suitable for the clinical and healthcare industries.

High-barrier and antibacterial films based on PET/SiOx for food packaging applications

High-barrier and antibacterial materials have potential applications in the field of preservative packaging for fresh meat products. In this paper, UV irradiation and silane coupling agent (KH550) were used to modify the surface of SiOx coating on polyester (PET)/SiOx film to prepare the PET/SiOx/chitosan and PET/SiOx/chitosan-nano-ZnO composite film, respectively. The contact angle test revealed that KH550 improved the surface hydrophilicity of SiOx significantly compared to UV irradiation, and thus PET/SiOx/chitosan and PET/SiOx/chitosan-nano ZnO composite films were successfully prepared and their physical and chemical properties were characterized. SEM images showed that the surface of the composite film was a smooth and layered structure. The mechanical performance testing of the films has revealed that mechanical performance of the PET was improved by SiOx deposition while the coating (KH550, chitosan, and chitosan-nano ZnO) does not affect the mechanical performance of PET/SiOx. The oxygen resistance of PET/SiOx films treated with KH550 was enhanced with the addition of chitosan and chitosan-nano ZnO coating, but the moisture resistance was slightly decreased. Furthermore, PET/SiOx/chitosan and PET/SiOx/chitosan-nano ZnO composite films showed excellent growth inhibition against Staphylococcus aureus and Escherichia coli. The PET/SiOx/chitosan-nano-ZnO films had exhibited the strongest inhibition of bacteria.

Chitosan–ZnO nanocomposite from a circular economy perspective: in situ cotton-used fabric recycling and the nanocomposite recovering

Chitosan–ZnO nanocomposite from a circular economy perspective: in situ cotton-used fabric recycling and the nanocomposite recovering

The chitosan/ZnO bio-nanocomposites with selective antibacterial efficiency

Chitosan/ZnO (CS/ZnO) nanocomposite materials have recently attracted intensive research interest because of their combined ZnO bactericidal activity and good biological compatibility of CS. In this study, ZnO NPs were synthesized via a green process using orange peel extract as a reducing agent. The CS/ZnO nanocomposites were chemically synthesized with different CS/ZnO weight ratios. The microstructure, morphology, and thermal stability of the nanocomposite materials greatly depended on the weight ratio of CS/ZnO. The nanocomposite materials exhibited strong antimicrobial activity towards both Gram-negative bacteria (Escherichia coli) and Gram-positive bacteria (Staphylococcus aureus) in the absence of UV light at all of the investigated CS/ZnO ratios. Due to the different characteristics of bacteria types, the activity inhibition towards E. coli was nearly constant in all samples, while that towards S. aureus slightly decreased with the increment of chitosan content. The results of this study suggest that the nanocomposites have potential applications in controlling the spread of infection by various bacteria.

Chitosan-ZnO Nanocomposites Assessed by Dielectric, Mechanical, and Piezoelectric Properties.

The aim of this work is to structurally characterize chitosan-zinc oxide nanoparticles (CS-ZnO NPs) films in a wide range of NPs concentration (0–20 wt.%). Dielectric, conductivity, mechanical, and piezoelectric properties are assessed by using thermogravimetry, FTIR, XRD, mechanical, and dielectric spectroscopy measurements. These analyses reveal that the dielectric constant, Young’s modulus, and piezoelectric constant (d33) exhibit a strong dependence on nanoparticle concentration such that maximum values of referred properties are obtained at 15 wt.% of ZnO NPs. The piezoelectric coefficient d33 in CS-ZnO nanocomposite films with 15 wt.% of NPs (d33 = 65.9 pC/N) is higher than most of polymer-ZnO nanocomposites because of the synergistic effect of piezoelectricity of NPs, elastic properties of CS, and optimum NPs concentration. A three-phase model is used to include the chitosan matrix, ZnO NPs, and interfacial layer with dielectric constant higher than that of neat chitosan and ZnO. This layer between nanoparticles and matrix is due to strong interactions between chitosan’s side groups with ZnO NPs. The understanding of nanoscale properties of CS-ZnO nanocomposites is important in the development of biocompatible sensors, actuators, nanogenerators for flexible electronics and biomedical applications.