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Nanotechnology has many applications in the medical field including drug delivery, biological devices, nanoelectronics, biosensors, nanocomposites, and biomaterials. Nanomaterial characterization is essential for the development and the utilization of many nanosystems for certain applications. The characteristic physicochemical properties of nanomaterials are important for their specific applications, which highlighted the importance of numerous characterization techniques. Nanomaterial characterization is needed to study their various physical and chemical properties, e.g., optical properties, size, structure, surface area, composition, morphology, oxidation state, electrochemistry. Usually, many techniques are used at the same time for determining all related nanomaterial properties for certain applications. Therefore, details of various characterization methods such as atomic force microscopy (AFM), transmission electron microscopy (TEM), mass spectrometry (MS), nuclear magnetic resonance (NMR), scanning electron microscopy (SEM), circular dichroism (CD), X-ray diffraction (XRD), dynamic light scattering (DLS), small-angle X-ray scattering (SAXS), zeta potential (ZP), Raman scattering (RS), scanning tunneling microscopy (STM), fluorescence correlation spectroscopy (FCS), and infrared spectroscopy (IR) are discussed.

The potential application of nanotechnology in the medical field ranges from nanomaterials and biological devices, to nanoelectronics biosensors, can be extended to molecular nanotechnology like biological machines. Nanomaterial characterization is a keystone for the development and adoption of nanomaterials for certain applications. The unique and novel physico-chemical properties of nanomaterial gave rise to a number of characterization techniques. Therefore, nanoparticles are characterized to study various physical and chemical features such as composition, structure size, morphology, surface area, optical properties, surface composition, oxidation state, and electrochemistry. The characterization of nanomaterials should not be limited to a single technique, because usually multiple measurements are needed to capture all pertinent nanomaterial characteristics. Hence, in this chapter, details of different characterization techniques such as transmission electron microscopy (TEM), atomic force microscopy (AFM), scanning electron microscopy (SEM), X-ray diffraction (XRD), dynamic light scattering (DLS), infrared spectroscopy (IR), and zeta potential (ZP) are discussed.

Wetting phenomena at surfaces and interfaces is an important field of research with numerous commercial applications. As example, superhydrophobic surfaces are used as self-cleaning, antibiofilm forming and antimicrobial materials nowadays. Given the potential impact, creating surfaces with tailored wetting characteristics employing various fabrication techniques is of great interest. One very promising fabrication technique, for creating such materials is the layer-by-layer (LbL) self-assembly. LbL is a versatile technique allowing incorporation of different types of drugs and materials and the ability to coat substrates of complex geometries. This review summarises recent progress in preparation of Layer-by-layer constructs and a role of surface and wetting parameters in this technique. Effect of various physicochemical properties on LbL construct characteristics also were discussed.

Experimental study is carried out to investigate natural convection from a vertical array of three horizontal square rods fixed adjacent to a vertical adiabatic wall and tested under constant heat flux condition. The experimental rig is designed and constructed for this purpose with variable horizontal distance ratio (H/D) in the range (0.125 < H/D < 3.0). The vertical distance between the rods is changed to get ratio (S/D) ranges of (1.5 < S/D < 4). The Rayleigh number tested is in the range of (1.26 × 106 < Ra < 6.6 × 106) with variable heating levels. The finite volume computational method is used to determine the flow and thermal field around the array of the square rods in different experimental configurations. The computed fields confirm the discussion of the experimental behavior of each rod in the array at each test configuration. Results show that the main parameters affecting the heat dissipation rate of each of the rods are position of the rod in the array, relative vertical distance between the rods and horizontal distance to the adiabatic side wall. The chimney effect noticed between the rods and the adiabatic wall plays a big role in heat transfer enhancement at certain (H/D) values. Experiments show that the ability of the rods to dissipate heat was increased at the largest tested vertical distances with the same behavior noticed for the small horizontal distances relative to the adiabatic wall with a tendency of each rod to behave as a free rod as its horizontal distance to the wall is increased. A dimensionless empirical correlation for each rod was found. Another general correlation for the whole array is used to relate the experimental data of each rod according to its position in the array.