Microscopic techniques morphological characterization

Microscopic techniques are extensively used to study the surface morphology of reinforcing fibers. The characterization of microstructure of polymer fibers provides an insight into stmcture-property relationship of the fiber. Microscopy techniques have been employed for the... 

Microscopic methods. While microscopic methods provide direct visual information on membrane morphology as discussed earlier, determination of pore size, especially meaningful pore size distribution, by this type of methods is tedious and difficult. Advances have been made on the electron microscopy techniques to visualize membrane surface pores. For example, Merin and Cheryan [1980] have developed a replica-TEM technique to observe membrane surface pores. Nevertheless, microscopic methods have remained primarily as a surface morphology characterization tool and not as a pore size determination scheme. 

In the context of polymers in industrial applications a number of key issues can be identified that are amenable to direct investigation and analysis by AFM approaches. From the preceding chapters the potential of probe microscopic techniques to conveniently visualize for instance surface (or bulk) morphologies and filler distributions has become obvious. Different classes of polymer materials, such as for instance thermoplastics, latexes, porous materials for membranes or thin films are subjected to different types of processing and treatments. The impact of all these modifications and the dependence on the process parameters can hence be closely monitored and in many cases quantitatively characterized by AFM. 

Morphological characterization can be conducted by light and electron microscope techniques and by X-ray diffraction and thermal analysis, often used to determine crystallinity. Standard mechanical tests can be used to determine strength, extension to break in tension, and toughness. Normally, a selection of characterization methods is used with samples exposed for selected periods. When mechanical tests are used, the exposure period increment must be fairly short, in case a recovery phenomenon is present (see the section Engineering Properties—Consequences of Photodegradation ). Other tests related to appearance. 

The optical microscope is a valuable tool in the laboratory and has numerous applications in most industries. Depending on the type of data that is required to solve a particular problem, optical microscopy can provide information on particle size, particle morphology, color, appearance, birefringence, etc. There are many accessories and techniques for optical microscopy that may be employed for the characterization of the physical properties of materials and the identification of unknowns, etc. Utilization of a hot-stage accessory on the microscope for the characterization of materials, including pharmaceutical solids (drug substances, excipients, formulations, etc.), can be extremely valuable. As with any instrument, there are many experimental conditions and techniques for the hot-stage microscope that may be used to collect different types of data. Often, various microscope objectives, optical filters, ramp rates, immersion media, sample preparation techniques, microchemical tests, fusion methods, etc., can be utilized. 

Therefore, selected spectroscopic and microscopic techniques are applied to the characterization of chemical structure formation and morphology in thin polyurethane (PU) layers on Au, Al, and Cu Infrared spectroscopy offers convenient access to the integral chemical properties of thin-fihn and bulk-like polymer samples, while optical (OM) and scanning force microscopy (SFM) allow detailed insights into homogeneity and topology. 

To obtain the morphology information, including phase separation and crystalline, we can now use microscopic techniques, atomic force microscopy, transmission electron microscopy, electron tomography, variable-angle spectroscopic ellipsometry. X-ray photoemission spectroscopy, and grazing-incidence X-ray diffraction. The detailed information of this characterization methods can be found from the specific reference (Li et al., 2012 Huang et al., 2014). 

Indeed, morphological characterization is usually performed at different length scales by using different microscopic techniques at the macroscopic level to obtain information on the incorporation of the filler into the rubber and. 

There are several characterization techniques for polymer blend systems in respect of mechanical behaviour, structure-property relationships, phase morphology characteristics and their interaction vs. miscibility or compatibility, and so on. These may be categorized as (i) microscopic techniques (ii) study of glass transition (iii) spectroscopic techniques (iv) scattering methods and (v) viscosity measurements. 

The characterization of Pis morphology involves a variety of different microscopic techniques such as optical microscopy (OM), scanning electron microscopy (SEM) and atomic force microscopy (AFM). Among them, AFM has proved to be a useful and attractive... 

Recently, several novel non-invasive techniques have been applied to characterize membrane fouling [1, 2]. Among them, optical and electron microscopic techniques have been recently used to visualize particle deposition, cake formation and membrane fouling. Conventional optical microscopy enables direct visualization of particle deposition during filtration, but its low resolution limits its applications. Additionally, conventional optical microscopy cannot be used to visualize cake structure and morphology since it has a very low axial resolution and requires ultrathin specimens to obtain a good visualization. 

Membrane characterization by CSLM has been rather limited when compared with other microscopic techniques such as SEM and atomic force microscopy (AFM). The earliest work found in the literature [13] records how van den Berg et al. used a combination of AFM and CSLM to study qualitative differences in the pore geometry of different brands of polypropylene membranes. The first reported applications that used only CSLM for membrane characterization [14,15] were by Charcosset et al. who used CSLM to characterize microporous membrane morphologies and to obtain values of surface porosity and pore size. The conclusions of those studies were that CSLM gave some characteristics on membrane morphology that SEM, which views only surfaces, cannot provide. However, as also mentioned previously in this chapter, they pointed out low resolution for membrane characterization as the main drawback of CSLM. This restricts the use of CSLM to the characterization of microfiltration membranes if measurements on pore size and surface porosity have to be performed. 

Drug-loaded medical textiles are composite materials in which the textile structure serves as the base material. Many traditional test procedures can be applied to the characterization of the base material. For example, the morphology of the fabric surface can be characterized by using microscopic techniques, including optical microscopy, scanning electron microscopy, and atomic force microscopy, which provide useful... 

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