CuO–cotton nanocomposite: Formation, morphology, and antibacterial activity

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Abstract

Copper oxide nanoparticles were synthesized and subsequently deposited on the surface of cotton fabrics using ultrasound irradiation. Optimization of the process resulted in a homogeneous distribution of CuO nanocrystals, 15 nm in size, on the fabric surface. The antibacterial activities of the CuO–fabric composite were tested against Escherichia coli (Gram negative) and Staphylococcus aureus (Gram positive) cultures. A significant bactericidal effect, even in a 1% coated fabric (%wt.), was demonstrated.

Introduction

It is known that metallic copper and copper complexes have been used to disinfect liquids, solids and human tissue for centuries [1]. Today copper is used as a water purifier, an algaecide, a fungicide, a nematocide, and a molluscicide, as well as an antibacterial and anti-fouling agent. Moreover, copper is one of a relatively small group of metallic elements that are essential to human health. These elements, along with amino and fatty acids and vitamins, are required for normal metabolic processes. In contrast to the low sensitivity of human tissue (skin or other) to copper [2], microorganisms are extremely susceptible to copper.

The development of new clothing products based on the immobilization of nanophased materials on textile fibers has recently received growing interest from both academic and industrial sectors [3]. A wide range of nanoparticles with various structures can be immobilized on the fibers, which brings new properties to the final textile product. These textiles can be widely used for hygienic clothing, wound healing, and medical applications in hospitals and other places where bacteria present a hazard.

However, as far as we know, there are not many publications on the production and application of the copper–textile composite with the exception of that of Gabbay et al. [4]. They describe that the copper-impregnated fibers of cotton and polyester containing 10%wt Cu demonstrated significant antifungal and antimicrobial properties. They performed the impregnation of copper oxide in the cotton fibers by a multi-phase soaking procedure, and in the polymer fibers, the copper oxide was inserted during the master batch preparation stage using the preliminary synthesized copper oxide powder.

In the current paper we have developed a new method for preparing cotton bandages with antibacterial properties by coating fabric surface with CuO nanoparticles via ultrasound irradiation. Sonochemical irradiation has been proven as an effective technique for the synthesis of nanophased materials [5], as well as for the deposition and insertion of nanoparticles on/into mesoporous ceramic and polymer supports, fabrics and glass [6], [7], [8]. The sonication process involves an in situ generation of CuO nanoparticles and their subsequent deposition on fabrics in a one-step reaction. In addition, the current research shows that even when coating a low concentration of CuO (1–1.5% wt.%), antibacterial activity is detected.

Section snippets

CuO coated fabric

CuO-coated bandages were prepared as follows: a cotton bandage (0.7 g, 10 × 10 cm) was added to an 0.005 M Cu(Ac)2·XH2O solution of ethanol:water (10:1) in a 100 ml sonication flask and irradiated for 1 h with a high intensity ultrasonic Ti-horn (20 kHz, 750 W at 70% efficiency, Sonics and Materials VCX600 Sonifier). During the first 5 min of the reaction, 0.5 ml of an aqueous solution of NH3xH2O was injected into the reaction cell. After adding the ammonium solution, the color of the reaction mixture

Characterization

The CuO content in the bandage was determined by volumetric titration with EDTA after treatment of the sample in 0.5 M HNO3 and controlled by inductive coupled plasma (ICP) analysis on the device ULTIMA JY2501. The X-ray diffraction (XRD) patterns of the product were measured with a Bruker D8 diffractometer (Karlsruhe, Germany) with Cu Kα radiation. The particle morphology and size were studied with a high resolution scanning electron microscope (HR-SEM), JEOL-JSN 7000F. Determination of CuO

Coating mechanism

The coating process involves an in situ generation of CuO nanoparticles and their subsequent deposition on the fabric in a one-step reaction via ultrasound irradiation. The copper oxide nanoparticles are formed during the irradiation according to the following reactions:Cu2+(aq) + 4NH3 · H2O(aq) → [Cu(NH3)4]2+(aq) + 4H2O[Cu(NH3)4]2+(aq) ) + 2OH(aq) + 4H2O → Cu(OH)2(s) + 4NH3.H2O(aq)Cu(OH)2(s)Δ → CuO(s) + H2O

The formation of copper oxide takes place through the ammonium complex, Cu[(NH3)4]2+.

Conclusions

CuO nanoparticles are uniformly deposited onto the surface of a cotton bandage by the sonochemical method. The process is a simple, efficient one-step synthesis. The physical and chemical analysis has shown that nanocrystalline copper oxide, 10–15 nm in size, is finely dispersed on the cotton surface without significant damage to the yarn's structure. The performance of fabrics coated with 1.4 wt.% CuO nanoparticles as an antibacterial agent was investigated, and their excellent bactericidal

Acknowledgement

This research was carried out as part of the activities of the LIDWINE Consortium, Contract no. NMP2-CT-2006-026741. LIDWINE is an IP project of the 6th EC program.

References (13)

  • A. Gedanken

    Ultrason. Sonochem.

    (2004)
  • R. Wang et al.

    Chem. Phys. Lett.

    (2004)
  • H.H.A. Dollwet et al.

    Trace Elem. Med.

    (1985)
  • J.J. Hostynek et al.

    Rev. Environ. Health

    (2003)
  • H.J. Lee et al.

    J. Mater. Sci.

    (2003)
  • J. Gabbay et al.

    Y. Shemer – Avni

    J. Ind. Text.

    (2006)
There are more references available in the full text version of this article.

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