Scanning electron microscopy suspensions

The nanotubes were first oxidized in nitric acid before dispersion as the acidic groups on the sidewalls of the nanotubes can interact with the carbonate groups in the polycarbonate chains. To achieve nanocomposites, the oxidized nanotubes were dispersed in THF and were added to a separate solution of polycarbonate in THF. The suspension was then precipitated in methanol and the precipitated nanocomposite material was recovered by filtration. From the scanning electron microscopy investigation of the fracture surface of nanotubes, the authors observed a uniform distribution of the nanotubes in the polycarbonate matrix as shown in Figure 2.3 (19). 

Slush powders were prepared from mass polymerised and suspension polymerised vinyl chloride polymers and the absorption of plasticisers into the polymers was investigated using the Haake rheomix procedure. The fusion behaviour of the powders was also investigated and the morphology of the particles analysed by scanning electron microscopy. The properties of the two different powders are compared. 6 refs. 

Figure 2-2 The conjunctiva shown by scanning electron microscopy with surface mucins intact (A). On higher magnification, note the strands (B) that allow the mucins to entrap particles and remove them from the tears. The tears form a reservoir for drug compounds, including those that are delivered as particulate suspensions. (Reprinted with permission from Burstein NL. The effects of topical drugs and preservatives on the tears and corneal epithelium in dry eye.Trans Ophthalmol Soc U K 1985 104 402-409.)...

When comparing results with other methods it is often necessary to dilute the suspensions without changing their state of agglomeration. Despite this, under electrokinetically stable conditions, excellent agreement was found in a comparison with the Mastersizer S, the Ultra Fine Particle Analyzer, the Sedigraph 5000D and scanning electron microscopy [265]. It was stressed however that sample preparation procedure was important. 

Suspensions of polypyrrole were prepared by the FeCls oxidation of pyrrole in an aqueous solution of methylcellulose (49). The product was dried and yielded films with conductivities of 0.2 S/cm. Scanning electron microscopy revealed globular polypyrrole embedded in the methylcellulose matrix. After several months, these suspensions remained stable with no detectable precipitation. Similarly, the electropolymerization of 3-methyl-thiophene in solutions of poly(methyl methacrylate) and poly(vinyl chloride) was reported (50, 51). 

Artificial asbestos fibre suspensions were prepared by tap (drinking) water, previously analyzed by scanning electron microscopy (SEM) and showing a fibre content, after prefiltration on 0.2 itm pore size cellulosic filter, of about 0.05 million fibres per litre (MFL) [9]. The chemical characteristics of this water are reported in Table 1. 

Reflux a suspension of polymer beads with attached microorganisms (250 mg) in 6 M HCI/methanol (150 mL) for 36 h, with regular monitoring of the extent of cell removal by scanning electron microscopy. 

Miller, A.F., Donald, A.M. Imaging of anisotropic cellulose suspensions using environmental scanning electron microscopy. Biomaciomolecules 4, 510-517 (2003)... 

Figure 14.6 (a) Scanning electron microscopy (SEM) image of MWNT/PANI composites and (b) shear viscosity versus shear rate for MWNT (0.1 wt.%)/PANI suspension in silicone oU. Reprinted with the permission from Ref [83]. Copyright 2005 Elsevier Ltd. 

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