Keywords: non-destructive control

Magnetic iron oxide nanoparticles: synthesis, surface modification, and functionalization by luminescent materials

https://doi.org/10.58224/2618-7183-2023-6-2-58-80
Abstract
From the standpoint of current science and engineering, iron oxide particles exhibit remarkable physical and structural features, particularly in the nanoscale range. Several methods have been studied to fabricate magnetic iron oxide nanoparticles and determine how they affect the size, size distribution, elemental composition, crystal structure, and a variety of other physical properties of nanoparticles. Advances in surface chemistry strategies for the functionalization of iron oxide-based magnetic nanoparticles (IONPs) are also explained. This review aims to present a summary of emerging activity relating to composite magneto-fluorescent nano-objects. Due to the high surface energies of iron oxide nanoparticles, agglomeration over time is often encountered. It is thus of prime importance to modify their surface to prevent aggregation and limit non-specific adsorption of fluorescent molecules onto it. Furthermore, the diverse strategies for the covalent linking with fluorescent organic dyes have been discussed, and the chemically relevant steps have been explained in detail. Surface coating and functionalization of iron oxide NPs allow them to attach to fluorescent molecules and prevent photoluminescence quenching entities by the magnetic core, making them a promising candidate for nondestructive magnetic inspections based on nanoparticles.
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APPLICATION OF ACTIVE AND PASSIVE THERMAL CONTROL IN DEFECTOSCOPY OF CONSTRUCTION MATERIALS AND PRODUCTS, FILLER STRUCTURES OF BUILDINGS AND CONSTRUCTIONS

https://doi.org/10.34031/2618-7183-2019-2-4-39-44
Abstract
One of the perspective and modern methods of nondestructive testing – thermal control is considered. The possibilities and advantages of thermal control in the identification of defects in various building materials and products, enclosing structures of buildings and structures are given. The short characteristics of the main defects of building materials and products, buildings and structures are proposed. The basic principles of identification of hidden (invisible) and obvious (visible) defects are briefly considered and practical results of construction flaw detection of objects for various purposes with the use of thermal imaging equipment are presented. On the example of a fragment of the enclosing building structure of piece building products in the form of ceramic bricks with artificially created technical defects in the process of qualitative analysis of thermograms zone of thermal temperature anomalies (method of active thermal control) are localized. For some enclosing structures of buildings and structures based on the results of thermal imaging identified obvious thermal defects, their qualitative analysis and recommendations for elimination (method of passive thermal control) are made.
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