Christine Campagne

High-Performance Polylactide/ZnO Nanocomposites Designed for Films and Fibers with Special End-Use Properties

Metallic oxides have been successfully investigated for the recycling of polylactide (PLA) via catalyzed unzipping depolymerization allowing for the selective recovery of lactide monomer. In this contribution, a metallic oxide nanofiller, that is, ZnO, has been dispersed into PLA without detrimental polyester degradation yielding PLA/ZnO nanocomposites directly suitable for producing films and fibers. The nanocomposites were produced by melt-blending two different grades of PLA with untreated ZnO and surface-treated ZnO nanoparticles. The surface treatment by silanization proved to be necessary for avoiding the decrease in molecular weight and thermal and mechanical properties of the filled polyester matrix. Silane-treated ZnO nanoparticles yielded nanocomposites characterized by good mechanical performances (tensile strength in the interval from 55 to 65 MPa), improved thermal stability, and fine nanofiller dispersion, as evidenced by microscopy investigations. PLA/ZnO nanocomposites were further extruded in films and fibers, respectively, characterized by anti-UV and antibacterial properties.

Atmospheric air-plasma treatments of polyester textile structures

The effects of atmospheric air-plasma treatments on woven and non-woven polyester (PET) textile structures were studied by surface analysis methods: wettability and capillarity methods, as well as atomic force microscopy/lateral force microscopy (AFM/LFM). The water contact angle on plasma-treated PET decreased from 80° to 50–40°, indicating an increase in the surface energy of PET fibres due to a change in the fiber surface chemical nature, which was confirmed by a higher fiber friction force measured by the LFM. The extent of water contact angle decrease, as well as the wash fastness of the treatment varied with the structure of the textile. Indeed the more porous the textile structure is (such as a non-woven), the fewer are the chain scissions of the PET at the fiber surface, during the plasma treatment. Thus, the level of surface oxidation and the weak boundary layers formation depend not only on plasma treatment parameters but also on the textile structure.

Polypropylene film chemical and physical modifications by dielectric barrier discharge plasma treatment at atmospheric pressure

Dielectric barrier discharge (DBD) technologies have been used to treat a polypropylene film. Various parameters such as treatment speed or electrical power were changed in order to determine the treatment power impact at the polypropylene surface. Indeed, all the treatments were performed using ambient air as gas to oxidize the polypropylene surface. This oxidation level and the surface modifications during the ageing were studied by a wetting method and by X-ray photoelectron spectroscopy (XPS). Moreover polypropylene film surface topography was analyzed by atomic force microscopy (AFM) in order to observe the surface roughness modifications. These topographic modifications were correlated to the surface oxidation by measuring with a lateral force microscope (LFM) the surface heterogeneity. The low ageing effects and the surface reorganization are discussed.

Processing and characterization of conductive yarns by coating or bulk treatment for smart textile applications

The use of intelligent materials reacting to external stimuli is rapidly growing in the field of technical textiles. In this paper, the processing of conductive yarns for the development of smart textiles is discussed. Two different methods are exposed: the coating of textile yarns using conductive polymers, and the bulk treatment of spinnable polymers by conductive nanofillers. In the first part of this article, polyaniline (PANI)-coated ultra-high-molecular-weight polyethylene (UHMWPE, Dyneema®) yarns were prepared. Their electrical, morphological and electro-mechanical properties including the temperature influence were investigated. Power handling of PANI-coated conductive yarns as a function of the current was also evaluated. Three different prototypes of conductive multiple yarns have been proposed. In the second part, the use of multi-walled carbon nanotubes as reinforcing conductive nanofiller for spinnable polymers has been studied. The major influence of the homogeneous dispersion of the nanotubes in the host matrix is particularly pointed out, and the electrical behaviour of the nanocomposite yarns has been investigated. Different conductive yarns, developed in our laboratory, are expected to be used as fibrous sensors, connection elements in smart clothing, electro-mechanical or thermal data acquisition devices and conductive fabrics for electromagnetic shielding applications.

Development of superhydrophilic and superhydrophobic polyester fabric by growing Zinc Oxide nanorods

ZnO nanorods were grown on microfibers of Polyethylene terephthalate (PET) fabric by seeding method to develop hierarchical roughness structure. XRD and XPS analysis show the presence of crystalline ZnO and chemical Zn species at the fiber surface at each stage of the process. Five series of samples with different seed concentrations have been realized, and their surface morphology and topography were characterized by AFM and SEM. Increasing seed concentrations lead to samples with superhydrophilic properties. Not only the water contact angle at fabric surface tends to zero but also the water capillary diffusion inside fabric is faster. Nanostructuration affects the structure inside the fabric, and further experiments with decane liquid have been made to get a better understanding of this effect. To study the superhydrophobicity, nanorods treated samples were modified with octadecyltrimethoxysilane (ODS) by two method; solution deposition and vapor deposition. The superhydrophobicity was characterized by measuring the water contact angle and water sliding angle with 5 μl water droplet. The samples modified with ODS by vapor deposition showed higher water contact angles and low water sliding angle than the ones modified with solution method. The lotus effect has been well correlated with the surface morphology of the nanorods structured fibers. The application of the Cassie-Baxter equation is discussed.

Development of Multilayer Microcapsules by a Phase Coacervation Method Based on Ionic Interactions for Textile Applications

The present study describes the development of multilayer microcapsules by 11 alternate additions of chitosan (Chi) and sodium dodecyl sulfate (SDS) in a combined emulsification and phase coacervation method based on ionic interactions. After an alkali treatment, microcapsules are applied on polyester (PET) fabric by a padding process to investigate their wash-durability on fabric. Air atmospheric plasma treatment is performed on PET fabric to modify the surface properties of the textiles. Zeta potential, X-ray photoelectron spectroscopy (XPS), wetting measurements, scanning electron microscopy (SEM), and atomic force microscopy (AFM) with surface roughness measurements are realized to characterize and determine wash durability of microcapsule samples onto PET. After alkali treatment, the microcapsules are selected for textile application because they are submicron sized with the desired morphology. The results obtained from various characterization techniques indicate that microcapsules are wash-durable on PET fabric pre activated by air plasma atmospheric as Chi based microcapsules can interact directly with PET by ionic interactions.

Study the multi self-cleaning characteristics of ZnO nanorods functionalized polyester fabric:

The conditions to make nanorods functionalized fabric superhydrophobic have been optimized to obtain three kinds of self-cleaning characteristics such as physical, chemical, and biological. Physical self-cleaning is the lotus effect which is characterized by measuring both water contact and sliding angles. Chemical self-cleaning is the degradation of color stains and solutions due to photocatalytic effect of ZnO when exposed to ultraviolet. Biological self-cleaning refers to the antibacterial activity of functionalized fabric which is characterized by using a Gram-negative bacterium (Escherichia coli) and a Gram-positive bacterium (Staphyloccocus aureus) by both qualitative and quantitative methods using NF ISO 20743:2009 transfer method. The chemical and biological self-cleanings are studied on nanorods functionalized fabric before and after hydrophobization.

Photocatalytic solution discoloration and self-cleaning by polyester fabric functionalized with ZnO nanorods

Polyester fabric was functionalized with ZnO nanorods grown by hydrothermal method. The ZnO seeds were deposited on fabric which provided the sites for growth of nanorods. The functionalized fabric showed self-cleaning by degrading color stains and solution discoloration under the effect of ultraviolet (UV) light which was studied using two azo and one triphenylemethylene dye. The stained fabric was exposed to UV light and K/S (K = absorption coefficient, S = scattering coefficient) values were measured by spectrophotometer. Most of the stains were degraded in first 300 min and they disappeared completely after 24 h. The solution discoloration was studied by using different concentrations of dyes and was characterized by measuring absorbance. The rubbing and washing durabilities of the functionalized fabric were also investigated.

Electrokinetic approach of adhesion between polyester fibres and latex matrices

Abstract The adhesive interaction between salt-treated polyester fibres and elastomeric matrices has been studied. Two types of approaches have been used to predict the impact of the salt treatment on the interaction between both jointing partners. First of all ξ -potential measurements have been used to characterize the interactions between fibre and matrix. Changes in the surface composition of salt-treated fibres were investigated by electrokinetic measurements using the streaming potential. Zeta potential of latex were determined using the electrophoresis method. The second approach is the characterization of adhesion by the interfacial shear strength determined from the single-fibre pull out test. We compared results issued from the two methods used during this study.

The Influence of 1-Butanol and Trisodium Citrate Ion on Morphology and Chemical Properties of Chitosan-Based Microcapsules during Rigidification by Alkali Treatment

Linseed oil which has various biomedical applications was encapsulated by chitosan (Chi)-based microcapsules in the development of a suitable carrier. Oil droplets formed in oil-in-water emulsion using sodium dodecyl sulfate (SDS) as emulsifier was stabilized by Chi, and microcapsules with multilayers were formed by alternate additions of SDS and Chi solutions in an emulsion through electrostatic interaction. No chemical cross-linker was used in the study and the multilayer shell membrane was formed by ionic gelation using Chi and SDS. The rigidification of the shell membrane of microcapsules was achieved by alkali treatment in the presence of a small amount of 1-butanol to reduce aggregation. A trisodium citrate solution was used to stabilize the charge of microcapsules by ionic cross-linking. Effects of butanol during alkali treatment and citrate in post alkali treatment were monitored in terms of morphology and the chemical properties of microcapsules. Various characterization techniques revealed that the aggregation was decreased and surface roughness was increased with layer formation.