Forms, fibres foils

Different analytical procedures have been developed for direct atomic spectrometry of solids applicable to inorganic and organic materials in the form of powders, granulate, fibres, foils or sheets. For sample introduction without prior dissolution, a sample can also be suspended in a suitable solvent. Slurry techniques have not been used in relation to polymer/additive analysis. The required amount of sample taken for analysis typically ranges from 0.1 to 10 mg for analyte concentrations in the ppm and ppb range. In direct solid sampling method development, the mass of sample to be used is determined by the sensitivity of the available analytical lines. Physical methods are direct and relative instrumental methods, subjected to matrix-dependent physical and nonspectral interferences. Standard reference samples may be used to compensate for systematic errors. The minimum difficulties cause INAA, SNMS, XRF (for thin samples), TXRF and PIXE. 

There were also attempts to find the compatibihty of this division with C-S-H morphology. C-S-H (I) forms crumbled foils, well visible imder the microscope, while for C-S-H (II) typical are fibre crystals or corrugated foils. Differences in morphology is observed in the case of itmer and outer product. 

Other comparison is difficult due to the authors examined the samples, combining polymer membrane foils, pol)mer fibres and colloidal dispersions for which the potential values vary strongly in dependence on their surface properties. Another chance is to compare results for PET [37], but the previous results were obtained for pH=5 and the potential = -33.6 mV is lower than presented here (see Fig. 1) due to the pH dependence mentioned above. Zeta potential for PET was determined [50] to be about -40 mV (only approximate estimation from figure [50]) using the same instrument as we used (the same cell, electrolyte, concentration, pH=6), this value agrees well with the present one of -54.7 mV, obtained for pH=6.2. Some pol5rmers inclusive PC and PS have also been measured in 0.001 mol/dm KCl, but in different analyser [51] and the data are not comparable with present ones. In addition PS was not in form of foil and other pol)nners were used without purification and the results can be affected by contaminants (stabilizers) in the pol)nners. 

Strong graphite fibres may be prepared by pyrolysis (at 1500°C or above) of oriented organic polymer fibres. Other graphite forms such as foams, foils, etc. can also be prepared. 

Objects for medical purposes made of plastics which are to have an antimicrobially active content of metals (or metal compounds) can be economically produced in that a plastic blank in foil, granulate or fibre form is coated with the desired metal (or metal compound) by the thin-film technique. The intermediate product thus obtained is then ground and mixed and processed further as the raw material for the desired final form. Sueh objects are thus antimicrobially active all over their surfaces and also on inner surfaces. Hence the full effect of the antimicrobially active substances, in this case oligodynamically active metals (or metal compounds) is obtained with only a small fraction of the quantities formerly required when they were included in the plastic in powdered form, thus resulting in considerable cost savings. 

In addition to internal or external coatings, barrier enhancers can be incorporated into the plastic as additives. These can include various metal oxides, glass fibre, mica, etc. Incorporating a foil ply between layers of plastic is a further way of obtaining excellent barrier properties, e.g. multilayer laminated tubes, cold formed blisters, and additional overwraps should not be ignored. 

Encasing constructions can be used with several membrane layers to form an intermediate space that can be filled with air or another insulating material, making U-values from 2.7 to 0.8 W/m K possible. U-values down to even 0.2 W/m can be obtained by using opaque, flexible mineral fibre fills or translucent insulating material, for example blister foils, as well as reflecting intermediate layers which are commonly used in space technology (ref LPS see Rg. 3.12). 

The low current efficiencies can be explained by the macroscopic appearance of the titanium deposits (Figure 4.10.2). In the beginning of a series of processes many coated fibres possessed large foils grown on the surface of the electrolyte during electrolysis. This indicates that a large amount of the current had not contributed to the faradaic process, but short circuits formed on the surface of the molten salt. 

The produced fibres were examined using SEM/EDS (Nova NanoSEM, FEI) method in order to determine morphology and distribution of the nanofillers. Changes in the materials structure caused by the presence of the nanofiller were assessed on the basis of thermal analysis methods (DSC/TG, STA 449F3, Netzsch). The measurements were performed in nitrogen atmosphere with temperature ramp 10 deg/min up to 600°C. The method was used to examine both the fibres and the prepared polymer foils. Comparison between results of the thermal analysis of the polymer foils and the electrospun fibres allowed to asses the influence of the forming method on structure of the nanocomposite material. 

---