Nuclear zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA lns~ments and Methods in Physics Research B 97 (1995) 265-268 zyxwvutsrqponmlkjihgfedcbaZYXWV s .__ I!!53 __ EISEVIER ~~~ B zyxwvutsrqpo Beam Interactions w ith Materials & Atom6 The use of an imaging plate as a detecting system in X-ray diffraction of polymers D. Villers ay * , C. Fougnies a, L. Paternostre a, C. Beumier b, M. Do&-e a a zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA Uniuersitt: de Mow-Hainaut, service de Physico-Chimie des Polymkes, Place du Part 20, B-7000 Mow, Belgium b Ecole Royale Militaire, Chaire d’Electricit& Auenue de la Renaissance 30. B-1040 Bruxelles, Belgium zyxwvutsrqponmlkjihgfe Abstract We present in this paper some applications of X-ray diffraction to polymer studies, using an imaging plate as the detector. The advantages of this system make it very attractive for a number of experimental measurements (WAXS and SAXS), especially on oriented polymer samples. 1. Introduction About ten years ago, the first studies using storage phospor screens demons~ated its interest as an integrating area detector [l-3]. Commercial imaging plate devices are now available that easily allow data acquisitions of two-di- mensional X-ray diffraction patterns, using this detector rather than conventional X-ray film. They are mainly used for protein single crystal structure analysis, but as already indicated by K. Sasaki [4] and Ogawa et al. [5], and as we show in this paper, the advantages of such device are numerous in the framework of polymer di~action studies. In addition to the main feature of the imaging plate, which is an integrating area detector designed to obtain quantita- tive intensity measurements, this system also has several general advantages : a good quantum efficiency and reso- lution (pixel size around 100 pm X 100 pm), a large dynamic range with a linear response (4 orders of magni- tude or 14 bits). Its ease of use and maintenance are a great asset to the non-specialist users who use X-ray dilation as a tool, in a normal laboratory or on a synchrotron beamline environment. However, some disadvantages were discussed in the literature [6]. They are inherent to the plates themselves (auto-exposition, self decay and uniform- ity of response) or to the image reader system (slight distortion in pixel size). Moreover we cannot forget it is not a pulse-counting device with a direct reading, and we have to exclude all experiments which require this particu- lar feature. Despite these disadvantages, none of them * Corresponding author. Fax: 32/6.5/37 30 54. Phone: 32/65/37 33 50. e-mail: sviIters @BMSUEMll (or ~V~l.UMH.AC.BE). constitutes a irredeemable defect. They just impose some restrictions in the type of experiments that can be consid- ered, and ask for appropriate corrections or calibrations, which is also the case for other types of detectors. In the following we show that the imaging plate remains a very good universal detector that can be used for polymer investigations. 2. Polymer studies Thermoplastics can often partially crystallize, but con- tain a large quantity of imperfections, disorder and defects. Consequently, the resulting diffraction patterns can be considered as mixtures of amorphous halos, and rather imperfect crystalline scattering (spots for oriented samples, or circles for isotropic materials). Their study requires the use of various types of camera and detectors. The process of c~stall~ation often induces the fo~ation of lamellae, with a long period of the order of 10 nm for most thermoplastics (see a lot of general, recent references in Ref. [7]). Small Angle X-ray Scattering (SAXS) experi- ments that can be performed with conventional X-ray films, for example in a Kiessig camera, can also be made using imaging plates under the same conditions. Wide Angie X-ray Scattering (WAXS) can also be mesured in the same camera, at a shorter camera length. The versatil- ity of the plates, which can be used in virtually any size and even distorted into a cylindrical shape, allows them to be used in all conventional cameras designed for films. The number, relative intensities and broadening of diffrac- tion spots obtained from polymeric samples matche in most cases the resolution and response provided by the image plate equipment. It is also possible to use image plates for time resolved investigations, which are common 0168-583X/9.5/$09.50 0 1995 Elsevier Science B.V. All rights reserved SSDI 0168-583X(94)00353-X V. POLYMERS