SEM Analyses

In the matrix material, the distribution of calcium carbonate whiskers and interfacial compatibility of whiskers and the matrix material greatly impact the properties of composite materials. 

Advantages of dry processing are that this method is convenient and simple and performance and microstructure analyses of the effect of the calcium carbonate whisker surface modification more intuitively and realistically reflect the interfacial action of whiskers and the matrix resin and dispersion of the whiskers in the matrix. Disadvantages are that because 

4 Calcium Carbonate Whiskers Modified by Silane Coupling Agents 

Silane coupling agents could be used for modification of various different organic functional groups on the surface of inorganic materials. The current research in this area is still very active. The common silane coupling agents for the surface modification of calcium carbonate whiskers are mainly KH-550, KH-560, and KH-570. 

Juan Hao et al. use KH-550 to modify calcium carbonate whiskers as follows. The silane coupling agent with a mass fraction of 0.5%-1.0% is formulated as a 95% ethanol solution, and then added to the whisker filler with stirring and dried at 120°C-l60°C. Yao et al. use KH-570 to treat calcium carbonate whiskers as follows. Add 1 g of KH-570 to 100 g of ethanol and then add 10 g of calcium carbonate whiskers after the silane coupling agent is dissolved. Disperse ultrasonically for 1 hour and then centrifuge for 10 minutes at 2000 rpm. Remove the supernatant, wash with ethanol, centrifuge, and remove the supernatant. Repeat three times and then dry. 

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Information on the morphology of the nanohybrid sorbents also was revealed with SEM analysis. Dispersed spherical polymer-silica particles with a diameter of 0.3-5 pm were observed. Every particle, in one s turn, is a porous material with size of pores to 200 nm and spherical particles from 100 nm to 500 nm. Therefore, the obtained samples were demonstrated to form a nanometer - scale porous structure. 

Fig. 15-12 Schematic illustration of the acid volatile sulfides (AVS)/simultaneously extractable metal (SEM) analysis. Refer to the text for details.

It was observed that this technique was able to produce microparticles with a mean diameter of approximately 10.17 + 3.02 pm in a reasonable to satisfactory yield depending on the formulation. This value was observed to be higher for the polymer weight ratio of 1 3 (87.00 + 4.25 %), which indicates that ESIOO improves the final result of the spray-drying process. According to the SEM analysis, the polymeric microparticles were shown to be quite similar in shape. Regardless of the formulation, they appeared to be mostly concave and asymmetric (Figure 12). 

For accurate determination of the particle size, the particle size analyzer was used and particle sizes of carbons sjmthesized are compared with commercial carbon black (N700 and N800, KCB) in Table 2. It was confirmed from particle size analysis that particle size of carbon increased with increase of methane flow rate, as also appeared from SEM analysis. 

In another catheter failure study, two samples of multi-layer catheters were tested. One catheter was breaking while the other was known to be a "good" sample. The catheters were freeze-fractured in order to obtain a cross-section view for SEM analysis, which was used to determine the construction of the catheter layers. ATR-FTIR spectroscopy was undertaken to identify the polymers used in the multi-layer catheter samples. 

Irrespectively of the iron content, the applied synthesis procedure yielded highly crystalline microporous products i.e. the Fe-ZSM-22 zeolite. No contamination with other microporous phases or unreacted amorphous material was detected. The SEM analysis revealed that size and morphology of the crystals depended on the Si/Fe ratio. The ZSM-22 samples poor in Fe (Si/Fe=150) consisted of rice-like isolated crystals up to 5 p. On the other hand the preparation with a high iron content (Fe=27, 36) consisted of agglomerates of very small (<0.5 p) poorly defined crystals. The incorporation of Fe3+ into the framework positions was confirmed by XRD - an increase of the unit cell parameters with the increase in the number of the Fe atoms introduced into the framework was observed, and by IR - the Si-OH-Fe band at 3620 cm 1 appeared in the spectra of activated Fe-TON samples. 

Removal of the outer organic layer can be achieved quickly and effectively through the introduction of hydrogen peroxide (H202) (8). Preparation of diatom samples for SEM analysis using H202 is described in the following protocol, the results of which can be seen in Fig. 2. 

Repeat the procedure so that the sample is washed a total of five times. After all washes have been completed, the sample is ready for SEM analysis. 

Figure 15.3 shows the results of the second SEM analysis designed to give a qualitative determination of the depth of fluorination. A carefully prepared cross section of the O-ring was analyzed using the so-called mapping technique. The light streak across Picture 3.2 shows where the fluorine is concentrated. With the aid of the microscale shown it can be estimated that the fluorination is approximately 5 pm deep. 

Various nanoporous AAO membranes have been obtained by varying different parameters such as applied voltage, temperature of electrolyte, electrolytic concentration and speed of rotation of electrolyte in two step anodization process. SEM analysis performed for evaluation of results. The relationship between pore size and variation of different parameters obtained. The synthesized membranes have been used as template for the synthesis of carbon nanotubes of different nano dimensions. 

The reaction product was identified as a-sulphur using XRD and SEM analysis. Sanchez and Hiskey (1991) reinvestigated the oxidation reaction of arsenopyrite and a two-step reaction sequence was suggested by the electrochemical measurements. The initial step was described by... 

The grafting of poly(ethylene oxide) chains onto PES and a poly(aryl ether) (PAE) has been used to increase the hydrophilicity of these non-ionic poly-mers. These systems were then blended with SPES. SEM analysis showed... 

The nanoparticle suspensions were centrifuged three times at 8,000 rpm for 15 minutes. After each centrifugation the pellets were resuspended in double-distilled water. However, SEM analysis of the pellets showed extensive aggregation-fragmentation of the microspheres (Figure 5), that... 

Although distinct "metal" and "adhesive" sides were apparent upon visual examination of the debonded surfaces treated with 100 ppm NTMP, SEM analysis showed the presence of an adhesive layer on the "metal" side. XPS analysis indicated low A1 and 0 and identical high C levels on both debonded sides, confirming a failure within the adhesive layer (cohesive failure), i.e., the best possible performance in a given adherend-adheslve system. This result is similar to that obtained using a 2024 A1 alloy prepared by the phosphoric acid-anodization (PAA) process (16) and indicates the importance of monolayer NTMP coverage for good bond durability (Fig. 4). 

UHMWPE foam with an average density of 0.11 g/cu.cm. was obtained by extracting the solvent xylene with alcohol. The foams were characterised by density measurement and thermal and SEM analysis. 6 refs. TURKEY... 

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