Fluorescence confocal optical

Bonilla, G., Tsapatsis, M., Vlachos, D.G., and Xomeritakis, G. (2001) Fluorescence confocal optical microscopy imaging of the grain bormdary structure of zeolite... 

Zeolite membranes are commonly characterized by SEM, XRD. TEM, EPMA, SEM-EDX, TEM-EOS, and Nitrogen adsorption are also used to study the morphology, microstructure and composition of zeolite membranes. Usually single gas permeation, mixed gas separation, pervaporation and vapor permeation are performed to evaluate the properties of zeolite membranes. Recently, some novel characterization techniques have been applied. Infrared reflectance measurement was used to characterize membrane thickness [19]. Fluorescence confocal optical microscopy was used to image the grain boundary structure of zeolite membranes [20]. FTIR-ATR method was used to characterize the T-O vibration of zeolite membranes [21],... 

Fluorescence confocal optical microscopy gives the possibility of observing the polycrystalline network of the zeolite membrane and so the internal defects not observable with SEM analysis ... 

Fluorescence confocal optical microscopy is a powerful tool for the non-destructive analysis of zeolite membranes. The grain boundary network of the zeolite layer can be observed along the thickness of the membranes and so the defects can be clearly visualized (Bonilla et al, 2001). 

Various solutions have been proposed for the reduction or elimination of autofluorescence. One way is to chemically suppress the autofluorescence signal with some reagents such as sodium borohydride, glycine or toluidine blue. However, in many cases, these approaches are either infeasible or ineffective, and none of them fully eliminates the problem. The second way is to use spectral unmixing algorithms subtracting the background fluorescence. This is only possible if you have at your disposal complicated, expensive confocal optics with sophisticated automated software (http //www.cri-inc.com/applications/fluorescence-microscopy.asp). 

One of the important functions of this infrared microscope is the measurement of the IR spectrum from a spatial region smaller than the diffraction limit. This possibility is already illustrated in Figure 29.4e. The TFD-IR spectrum, that corresponds to the IR absorption spectrum, was measured from a fluorescence region smaller than the IR diffraction limit. Infrared spectroscopy in a sub-micron region will be possible by using a high NA objective lens with the confocal optical system. 

We have performed super-resolution infrared microscopy by combining a laser fluorescence microscope with picosecond time-resolved TFD-IR spectroscopy. In this chapter, we have demonstrated that the spatial resolution of the infrared microscope improved to more than twice the diffraction limit of IR light. It should he relatively straightforward to improve the spatial resolution to less than 1 pm by building a confocal optical system. Thus, in the near future, the spatial resolution of our infrared microscope will be improved to a sub-micron scale. 

Fig. 1. Examples of fluorescence preparations of Drosophila whole mounts using the protocols is described in this chapter. All confocal images were obtained with a LeicaTCS4D confocal microscope, (a) Confocal optical section of a D. melanogaster embryo whole mount at blastoderm stage double stained with phalloidin—rhodamine (red) and DAPI (blue) to allow simultaneous visualization of nuclei and cortical actin around cell membranes. Anterior is to the left.

Figure 4.14 Fluorescence confocal image of (a) P3DDT + PEO fibers (b) SEM image of a sample of fibers (c) fluorescence confocal image of P3DDT fibers (PEO was removed by washing with acetonitrile) (d) SEM image from the same sample of fibers. (Reprinted with permission from Synthetic Metals, Electrospun polyalkylthiophene/polyethyleneoxide fibers Optical characterization by A. Bianco, C. Bertarelli, S. Frisk et al., 157, 276-281. Copyright (2007) Elsevier Ltd)...

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