R. Lopez

AITEX (Textile Industry Research Association), Alicante, Valencia, Spain

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Publications (5)4.47 Total impact

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    ABSTRACT: The use of nonwoven textile substrates for filtration and absorption purposes is generalized due to the high surface area they can provide. Many of these applications require good wetting properties to increase efficiency. In this work, low pressure plasma treatment with a CH4-O2 mixture gas has been used to increase surface wettability and subsequent absorption properties on nonwoven polypropylene substrates. CH4 plasma treatment leads to a plasma polymerization process which results in hydrophobic surface finishing, but in combination with O2, it is possible to form a functionalized plasmapolymerized layer thus improving wetting properties. Changes in wetting properties have been studied by contact angle measurements showing that optimum wetting properties are obtained with exposure times to plasma treatment of about 10 min, and no significant changes are obtained for longer exposure times. Absorption efficiency has been followed by determining three different parameters by the guidelines of the UNE-EN-ISO 9073-6 standard: wetting time, liquid absorption capacity (LAC) and liquid propagation rate or absorption speed. All these properties are remarkably improved as the exposure time to CH4-O2 plasma increases; this improvement is remarkably high for relatively short exposure times (5–10 min) and no significant changes are obtained for long exposure times so that, it is possible to conclude that previous plasma treatment with exposure times in the 5–10 min range is an efficient method to improve overall absorption properties of nonwoven polypropylene substrates.
    Fibers and Polymers 01/2012; 13(9):1139-1144. · 0.91 Impact Factor
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    ABSTRACT: In this work we have used low-pressure plasma with a gas based on methane and oxygen mixture to improve wettability and durability of a PP nonwoven fabrics. The obtained results show good durability with the use of methane-oxygen plasma mixture gas. The effects of the plasma are similar to a plasmapolymerization process but in this case we obtain hydrophilic properties with high durability. The surface does not suffer important changes and the roughness of the material remains constant.
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    ABSTRACT: The use of surface treatments at industrial level is generalized as they allow obtaining a wide variety of properties such as soft in the touch, hydrophilic behavior, and biocompatibility. The use of low-pressure plasma techniques with organic gases or organic mixtures is an easy way to obtain surface coatings very small in depth through plasma-polymerization processes that can be assimilated to a plasma-enhanced chemical vapor deposition (PECVD) process. In this work, we have carried out a plasma-polymerization process on a polypropylene (PP) film to obtain a hydrophilic coating. To obtain this, the film surface has been treated on a low-pressure plasma reactor with a methane–oxygen mixture gas with a volume ratio of 80 : 20, respectively. The chemistry changes in the outermost layers of the deposited coating have been investigated with X-ray photoelectron spectroscopy (XPS). The different processes that take part as a consequence of the interaction between the plasma gas species and the PP film surface mainly drive to the deposition of an organic layer, which is functionalized with oxygen-based species as XPS study reveals. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
    Journal of Applied Polymer Science 12/2008; 111(6):2992 - 2997. · 1.40 Impact Factor
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    ABSTRACT: The aim of this work is to study the effect of surface treatment of a polypropylene film with low-pressure plasma using CH4–O2 mixture gas in an 80:20 ratio. The effect of the variation of the plasma treatment conditions has been studied to optimize the plasma effects. The film wettability has been analyzed by the study of the variation of free surface energy and its polar and dispersive components. The surface functionalization of the PP film was also analyzed by X-ray photoelectron spectroscopy (XPS) and attenuated total reflectance infrared spectroscopy (FTIR-ATR) analysis. The surface topography was analyzed by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The CH4–O2 plasma treatment induces the ablation inherent of a traditional plasma treatment and polymerization mechanisms to take place simultaneously at the treated surface. The PP film treated with CH4–O2 plasma shows a remarkable improvement on the surface free energy mainly caused by surface functionalization as XPS reveals. Slight changes in surface topography are observed, but they do not contribute in a significant way to improve wettability.
    Journal of Materials Science 01/2008; 43(10):3466-3473. · 2.16 Impact Factor
  • Journal of Applied Polymer Science - J APPL POLYM SCI. 01/2008; 110(2):1201-1207.