Plasma surface modification of polymer powders with application to thermal energy storage

Abstract

SynopsisThe rotating bed plasma reactor described here permits cniform surface modification of relatively large amounts of powder materials. Scale-up to even larger batches of solids appears to be feasible. Some preliminary experimental data on the plasma surface modification of polymer powders have been presented. The results show that the flow rate, time of treatment, and type of feed gas are important operating parameters which influence the final surface character. One particular application of plasma-modified polymer powders was explored; by crosslinking and/or chemically modifying only the outermost surface regions of these powders, various polymeric materials may be rendered useful for use in thermal storage slurries. The major advantage of the surface-modified plasma treated powders over the bulk-modified powders used previously is the retention of essentially all of the pristine polymer heat of fusion in the surface-modified materials.

Plasma treatment of polymer powders – from laboratory research to industrial application

“…The most common analytical methods to characterize plasma‐treated polymer powders are summarized in Table . X‐ray photoelectron spectroscopy (XPS) is widely used to analyze the powder's atomic surface composition and enables the identification of introduced functional groups . Fourier‐transform infrared spectroscopy (FTIR) and attenuated total reflectance infrared spectroscopy (ATR‐IR) are used to probe samples up to a depth of about 4–5 μm .…”

Peptide with endothelial cell affinity and antiplatelet adhesion property to improve hemocompatibility of blood‐contacting biomaterials

“…Table shows the atomic composition of the samples. The F/C atomic ratio decreased in the modified ePTFE samples . In particular, ePTFE‐4 displayed the lowest F/C atom ratio.…”

“…The band at approximately 400 eV is connected with the C(O)N group. The N1s signal was deconvoluted into two major components at 399.5 eV and 401.2 eV, corresponding to the CN and NCO configurations, respectively . A significant change in the C 1s spectra was observed in the case of ePTFE‐2 (Figure B).…”

“…X‐ray photoelectron spectroscopy spectra were recorded using an ESCA 3400 device (Shimadzu, Kyoto, Japan). Electron binding energy was calibrated to the C 1 s peak (CF2) n to 292.4 eV . Background subtraction, peak integration, and fitting were carried out using Kratos software (Figure and Table ).…”

Surface crosslinking of high‐density polyethylene beads in a modified plasma reactor

“…It is possible that some of these groups are detected in-depth on the basis of a gradient in the polymer composition from a CH 2 -CH 2 state in the bulk to a CF 2 -CF 2 state on the surface. [12][13][14] The positions of FTIR absorption peaks are summarized in Table III. Figure 7 shows the comparison of DSC diagram of the plasma-untreated HDPE particle with that of plasma-treated HDPE particle prepared under the condition of 100 W RF power for 1 h (at 100 mTorr).…”