**Zinc Oxide — Linen Fibrous Composites: Morphological, Structural, Chemical, Humidity Adsorptive and Thermal Barrier Attributes**

Narcisa Vrinceanu, Alina Brindusa Petre, Claudia Mihaela Hristodor, Eveline Popovici, Aurel Pui, Diana Coman and Diana Tanasa

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/55705

**1. Introduction**

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The augmented requirement for fibrous supports (yarns) possessing multifunctionality implies powerful emerging multidisciplinary approaches as well as the connection with the traditional scientific disciplines [1]. Finishing processes through nanoparticles were among the first commercial application in textiles domain.

Due to poor fixing of these nanoparticles on the textile surface, these finishes were not resistant to washing. Nanofinishings with improved bonding properties in fabrics and also impart desired wettability will result by using hydrophobic/hydrophilic functional polymer fibrous matrices as dispersion medium for nanoparticles.

Nanoparticles are extremely reactive, due to their high surface energy, and most systems undergo aggregation without protection of their surfaces. To eliminate or minimize generated waste and implement sustainable processes, recently green chemistry and chemical processes have been emphasized for the preparation of nanoparticles [2]. Much attention is now being focused on polysaccharides used as the protecting agents of nanoparticles. As stabilizing agent soluble starch has been selected and as the reducing agent in aqueous solution of AgNO3 for silver nanoparticle growth, and a-D-glucose, has been elected. To maintain noble metal (platinum, palladium and silver) nanoparticles in colloid suspension, Arabinogalactan has been used as a novel protecting agent for [3]. Synthesized platinum, palladium and silver nanoparticles with narrow size distribution have been achieved by using porous cellulose

© 2013 Vrinceanu et al.; licensee InTech. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2013 Vrinceanu et al.; licensee InTech. This is a paper distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

fibers as the stabilizer [4]. Pt nanoparticles can catalyze the carbonization of cellulose and mesoporous amorphous carbon is fabricated in high yields. The results are carbon-based functional composites with metal nanoparticles, showing that self-supporting macroporous sponges of silver, gold and copper oxide, as well as composites of silver/copper oxide or silver/ titania can be routinely prepared by heating metal–salt-containing pastes of dextran, chosen as a soft template [5,6]. Polysaccharides could be used as stabilizer to synthesize nanoparticles of metal oxide and sulfides. Zinc oxide nanoparticles can be synthesized using water as a solvent and soluble starch as a stabilizer [7-9] while CdS nanoparticles have been prepared in a sago starch matrix.

of water can be both harmful and beneficial depending on the material and how it is used. Consequently, the point to determine a correlation between morphological, structural and chemical characterization and the water vapor sorption behavior of the analyzed samples has been emphasized. Consequently, the obtained textiles should find their applicability in textile processing industry subdomains, where a certain level of hydrophilicity/hydrophobicity is

Zinc Oxide — Linen Fibrous Composites: Morphological, Structural, Chemical, Humidity Adsorptive and Thermal

Barrier Attributes

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http://dx.doi.org/10.5772/55705

The main cause of polymeric materials degradation is the exposure to various factors such as: heat, UV light, irradiation ozone, mechanical stress and microbes. Degradation is promoted by oxygen, humidity and strain, and results in such flaws as brittleness, cracking, and fading [11-13]. There have been research reports targeting nanosized magnetic materials synthesis,

The applications of ZnO particles are numerous: varistors and other functional devices, reinforcement phase, wear resistant and anti-sliding phase in composites due to their high elastic modulus and strength. Otherwise, ZnO particles exist in anti-electrostatic or conductive phase due to their current characteristics. Few studies have been concerned with the applica‐ tion of ZnO nanoparticles in coatings system with multi-properties. The nano-coatings can be obtained by the traditional coatings technology, i.e., by filling with nanometer-scale materi‐ alsBy filling with nano-materials, both structure and functional properties of coatings can be modified. Super-hardness, wear resistant, heat resistance, corrosion resistance, and about function, anti-electrostatic, antibacterial, anti-UV and infrared radiation all or several of them

Another idea this paper review was centered to was to study the thermal degradation behavior of some textile nanocomposites made of nano/micron particle grade zinc oxide and linen fibrous supports, and to discuss the thermal degradation mechanism of the above mentioned structures. There is also potential to highlight the effect of the functionalization agent - MCTβ-CD (monochlorotriazinyl–β–cyclodextrin) on the thermal stability and degradation mecha‐

In order to characterize the surface morphology and chemical composition of the treated supports, instrumental methods were conducted to measure the particle sizes of the reduced zinc oxide particles. The understanding of the thermal behavior of these fibers is very impor‐ tant since in general several conventional techniques used in textile processing industry, are

The MCT-β-CD (monochlorotriazinyl–βeta-cyclodextrin) under the trade name CAVATEX or CAVASOL® W7 MCT (CAVATEX) from Wacker Chemie AG, Zn(OAc)2, with an assay of 97%, urea and acetic acid (assay 99%) from CHIMOPAR, cetyltrimethylammonium bromide

Two 100 % twill linen desized, scoured and bleached supports, each of size 3 cm × 3 cm were used as fibrous support. One of the supports has been coated with a certain concentration of

(CTAB) from Merck Company, with an assay of 97% were utilized

MCT-β-CD (monochlorotriazinyl– β -cyclodextrin) [14-17].

mandatory.

can be realized.

having significant potential for many applications.

nism of ZnO nanocoated linen fibrous samples.

conducted at high temperature.

In an earlier study, ZnO nanoparticles synthesis can be made with the assistance of MCT-β-CD (monochlorotriazinyl–β -cyclodextrin) by using a sol-gel method [10]. MCT-β-CD, a commercially available β- cyclodextrin with a reactive monochlorotriazinyl group, is used as a stabilizer. The so called anchor group reacting with cellulose hydroxyl radicals and cyclo‐ dextrin molecule is covalently bonded, to the fiber surface. The stable bound of cyclodextrin onto the textile fibers allows its properties to become intrinsic to the modified supports, thus a new generation of *intelligent textiles possessing* enhanced sorption abilities/capacities, as well as possessing active molecules release wasborn. Besides, as polysaccharide, MCT-β-CD shows interesting dynamic supramolecular associations facilitated both by inter- and intra-molecular hydrogen bonding, and polar groups. When a material is exposed to environmental water vapors, the water molecules firstly reacts with surface polar groups, forming a molecular monolayer.

Zinc oxide (ZnO), an n-type semiconductor, is a very interesting multifunctional material and has promising applications in solar cells, sensors, displays, gas sensors, varistors, piezoelectric devices, electro-acoustic transducers, photodiodes and UV light emitting devices. The adhesion between the ZnO nanoparticles and polymer through simple wet chemical method is rather poor and the nanoparticles may be removed from the host easily. In light of this, it is believed that the hydrothermal method can be a more promising way for fabricating nano‐ materials because it can be used to obtain products with modified morphological and chemical attributes with high purity, as well as stability in terms of water vapour sorption-desorption. Zn2+ ions can penetrate into the interior of linen fibrous support (fabric) easily when soluble salt such as zinc acetate (Zn (OAC)2) is used. Reaction of Zn2+ ions leads to crystallization of ZnO nanoparticles within the linen fabric and to the formation of an encapsulated complex in the hydrothermal environment. The formation procedure can be described through two steps as shown in Fig. 1. Firstly, coordination compounds are formed through chelation between Zn2+ ions and the hydroxyl groups of linen fabric. Secondly, the in-situ crystallization of Zn chelate complex occurs under the hydrothermal treatment and forms a ZnO- coated linen fabric. The ZnO nanoparticles can thus be attached firmly within the linen fiber surface.
