Fibers Field-emission scanning electron

Fujii et al. [13] studied morphological structures of the cross section of various hollow fibers and fiat sheet membranes by high-resolution field emission scanning electron microscopy. Figure 6.8 shows a cross-sectional structure of a flat sheet cellulose acetate RO membrane. The layer near the top surface is composed of a densely packed monolayer of polymeric spheres, which is supported by a layer formed with completely packed spheres. The contours of the spheres in the top layer can be observed. The middle layer is also composed of loosely packed and partly fused spheres, which are larger than the spheres in the surface layer. In the middle layer, there are many microvoids, the sizes of which are the same as the spheres. The layer near the bottom is denser than the middle layer, and the spheres are deformed and fused. Interstitial void spaces between the spheres, which may be called microvoids, are clearly observed. This structure seems common for the flat sheet as well as the hollow fiber membranes. For example. Fig. 6.9 shows a cross section of a hollow fiber made of PMMA B-2 (a copolymer containing methyl methacrylate and a small amount of sulfonate groups). The inside surface layer is composed of the dense structure of compactly packed fine polymeric particles. The particle structure of the middle layer... 

Figure 12.8 Field emission scanning electron microscope images of (a) ceUulose-only fibers, (b) ceUulose-heparin composite fibers. (Adapted from Reference [99]).

CL spectra were collected in a field-emission gun scanning electron microscope (FEG-SEM, Hitachi SE-4300) equipped with a CL device. The CL device consisted of an ellipsoidal mirror and a bundle of optical fibers to collect and to transmit the CL emission into a spectrally resolved monochromator (Jobin-Yvon/Horiba Triax 320,). A 150 gr/mm grating was used throughout the... 

Campos et al. [21] studied sisal flber-reinforced TPS and polycaprolactone, both biodegradable pol5miers. Sisal fibers (5% and 10%) were extruded in a twin-screw extruder with TPS/ polycaprolactone (80 20 wt). Films were produced with a single extruder and analyzed by field emission gun scanning electron microscopy, mechanical tests, thermogravimetric analysis, and differential scanning calorimetry. The morphology of the composites with 10% sisal fiber content presented an interface... 

Scanning Electron Microscope The cross sections of selected fibers were imaged by a Hitachi Field Emission SEM (EE-SEM 4800). 

---