Membrane morphology characterization

Membrane morphology characterization ias carried out using several microscopy techniques (SEM, CSLM, AFM, etc.). Two case studies are presented and discussed next. 

Membrane morphology and, in the case of porous membranes, pore size and orientation and porosity are vital to the separation properties of inorganic membranes. As the general characterization techniques evolve, the understanding of these miciostnictures improves. 

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. 

Ferromagnetic Fei-sNis(P) (x=24-65 at.%.) columns have been chemically deposited into porous polycarbonate membranes with pore diameters of 0.1-4 pm. The morphological characterization by TEM reveals the shape features in synthesized columns. Their magnetic perpendicular anisotropy due to the shape anisotropy of columns was observed. 

As the modern characterization method advances, the details of the membrane morphology are being revealed. 

In this chapter, the experimental details of the SMM synthesis and characterization as well as the membrane preparation, characterization, and testing are thoroughly described in the following examples. Moreover, the effects of the SMM type on the membrane morphology as well as its performance were clearly identified. Furthermore, the performance of the newly developed membranes was compared to a commercial PTFE membrane in terms of the permeate water flux and the separation factor. 

The morphology characterization of hybrid membranes is very important to identify the possible interfacial morphology and particle dispersion in the final membrane matrix. Electron microscopy is typically used to investigate the filler dispersion and the hybrid membrane morphology. Scanning electron microscopy is the most frequently used technique, and it allows the characterization of the sample surface. The sample s cross-sections can be examined to analyze the inner morphology. Transmission electron microscopy is also a very useful technique because it allows a direct evaluation of the inner morphology of the sample. 

Another possible approach to indirectly characterize the membrane morphology is based on the investigation of the free volume within the matrix. Density measurements [119,120] and positron annihilation lifetime spectroscopy evaluation [47] are common methods. Typically, the comparison between the theoretical density or free volume (calculated by simple additivity rules) and the experimental one can reveal the presence of a good interfacial morphology or the presence of interface voids or clustering formation. Fig. 7.13 shows the influence of filler content on the morphology of poly(trimethylsilyl propyne) (PTMSP)/Ti02 NCMs in terms of the volumetric fraction of interface voids as calculated from a comparison of the expected and measured membrane density [119],... 

Braun F, Tarditi A, Miller JB, Comagha LM. Pd-based binary and ternary alloy membranes morphological and perm-selective characterization in the presence of H2S. J Membr Sci 2014 450 299-307. 

Scanning or transmission electron microscopy (SEM or TEM, respectively) are typically used for performing morphological characterization of nanomaterials obtained by template synthesis. The resolution of the images is improved if the nanomaterial is separated from the host membrane. 

Kim, H. S., K. S. Kim, H. J. Jin, and l.-J. Chin (2005). Morphological characterization of electrospun nano-fibrous membranes of biodegradable poly(L-lactide) and poly(lactide-co-glycolide). Macromolecular Symposia 224(1) 145—154. 

This chapter is divided in two sections. The first presents a review of the different techniques used for the morphological characterization of membranes. The second explains some cases studies developed by authors to carry out the mentioned characterization, adding emphasis on software developed by the authors to achieve these purposes, providing quantitative, fast and systematic analysis. 

Nevertheless, when performing membrane morphological (i.e. topographical, structural) characterization it is always encouraged to use various and complementary characterization techniques. 

I 3 Microscopy Techniques for the Characterization of Membrane Morphology Polysulfone... 

There are several kinds of membrane characterization, depending on the information and knowledge required (morphological structure, chemical properties, permeability, selectivity, etc.). In this case, we focused on the morphological characterization of polysulfone membranes by using the SEM technique. 

The morphological characterization of a flat membrane implies, basically, acquiring three micrographs two corresponding to surface and one to cross-section. 

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