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Nanomagnets
Published in Ram K. Gupta, Sanjay R. Mishra, Tuan Anh Nguyen, Fundamentals of Low Dimensional Magnets, 2023
Biswanath Bhoi, Mangesh Diware
Self-assembly is a thermodynamically driven process that organizes structural units (such as atoms, or molecules or particles) into larger arrays of complex shapes that can withstand thermal fluctuations due to the system’s inherent nano-scale forces. The process can be stimulated by either using a nanostructured surface known as template-assisted assembly or by applying external fields known as field-assisted assembly [1]. The external magnetic field guides the organization process for field-assisted assembles and controls their dimension and anisotropy. Self-assembly is a popular bottom-up approach for nanofabrication that has recently gained popularity.
Dendrimers in Gene Delivery
Published in Neelesh Kumar Mehra, Keerti Jain, Dendrimers in Nanomedicine, 2021
Dnyaneshwar Baswar, Ankita Devi, Awanish Mishra
These are the following surface properties of dendrimers, which appears suitable for their diverse biological properties. Molecular identification results at dendrimer surfaces are characterised through a vast number of usually similar terminal groups present on the dendritic organism. The surface of dendrimers contains polyelectrolyte groups, which are attracted electrostatically toward oppositely charged molecules. For example, electrostatic interactions within charged species affect the accumulation of methylene blue on the dendrimer surface and polyelectrolyte dendrimers and the coupling of copper complexes and nitroxide cation radicals (Abbasi et al. 2014; Ahmed et al. 2016). Polyvalency is a biological property of dendrimers, which is required to provide various interactions with biological receptors. Self-assembly is an intrinsic property of molecules that results in the formation of defined arrangement of molecules through various inter and intramolecular forces. Recently, it has been found that dendritic structures also possess a self-assembling property due to their specific structure that comprises terminal groups, core unit and branched units. Through this property, dendrimers convert into the dendrons containing a polytopic or ditopic core structure (Abbasi et al. 2014).
Synthesis, Designing and Challenges of Functionalized Polymeric Nanomaterials and Their Spectroscopic Applications
Published in Kaushik Pal, Nanomaterials for Spectroscopic Applications, 2021
Jitha S. Javan, A. S. Sethulekshmi, Gopika Venn, Appukuttan Saritha, Kuruvilla Joseph
Self-assembly of polymers is an important behavior since it has tremendous applications in various fields due to the formation of hierarchical structures in different organic solvents [12-14]. Self-assembly is a process by which un-ordered components are getting ordered due to the internal interactions without any external physical force. Self-assembly is a very important parameter as we are familiar with the self-assembly of molecules, lipids, polymers and colloids that occur in nature [15-17]. This process often leads to the formation of functional structures and the easiest and simple example of self-assembly is the cleansing action of soap. The arrangement of soap molecules in water to form a micellar structure by the internal interactions of hydrophilic and phobic ends of soap molecules with water [18, 19] is similar to the self-assembly of block copolymers and macromolecules like lipids and dendrimers. In short, self-assembly is the conversion of large molecules to nano levels [20, 21].
Self-assembling behaviour of new functional photosensitive cinnamoyl-based reactive mesogens
Published in Liquid Crystals, 2020
Alexej Bubnov, Martin Cigl, Nela Sedláčková, Damian Pociecha, Zuzana Böhmová, Věra Hamplová
Self-organisation is a process due to which a disordered system of simple constituents can form an organised structure or pattern as a consequence of specific local interactions among those components. When the constitutive objects of such a system are molecules, the self-assembly phenomenon is a process of spontaneous, and usually reversible, organisation of molecules into ordered assemblies by non-covalent interactions. Some organic materials can exhibit the liquid crystalline (LC) behaviour, which is a specific example of the self-organising system, that can be controlled, tuned or changed by an applied external stimulus, like external electric/magnetic field, mechanical stress or irradiation by light of different wavelength [1–3]; the last is actually of extremely high interest for a number of practical applications [4–11]. Various structures and specific properties characteristic for the low-molar-mass LC materials can be stabilised by grafting them on the polymeric backbone while designing the macromolecular structures. During last decades, self-assembling materials with desired functionality represent a fascinating area of intense research of the soft matter and liquid matter communities [12–16], which provides a highlighted approach for the design of new material structures [17]. However, it is quite difficult to predict and keep under control the properties of the self-assembling materials [18–20]. One of the most exciting classes of organic materials that is able to self-assemble at nanoscopic length scale are those exhibiting the LC behaviour which can be tuned by the light illumination.
Design and self-assembling behaviour of comb-like stereoregular cyclolinear methylsiloxane copolymers with chiral lactate groups
Published in Liquid Crystals, 2019
Irina Petrova, Aleksej Gaj, Damian Pochiecha, Maksim Shcherbina, Nataliya N. Makarova, Alexej Bubnov
In general, the self-assembly is a process in which the disordered system of simple units can form an organised structure or pattern as a consequence of specific local interactions among those units. When the constitutive objects are molecules, the self-assembly phenomenon is a process of spontaneous and reversible organisation of the molecules into ordered assemblies by non-covalent interactions. In our days, self-assembling materials with desired functionality and physical properties represent a fascinating area of intense research, which provides a highlighted approach for design of new advanced material structures [1–3]. One of the most exciting but special classes of organic materials that is able to self-assemble at nano- and mesoscopic length scales are those forming the polar layered structure of nanometre dimensions, so-called chiral smectic liquid crystals (LCs). The intermolecular interactions, responsible for the self-organisation, can be precisely adjusted by appropriate molecular design, e.g. by building the molecule from various units [4–7]. One of the powerful tools for stabilisation and advancement of the mesomorphic and structural properties is the design of side-chain polysiloxanes [7–9] or organosiloxane-based materials [10–13]. General objective of the present work is to contribute to acquiring systematic data on molecular architecture–nano-organisation relationship for a specific type of nano-organised system based on the derivatives of the lactic acid, which are intensively studied over last decades [11,12,14–19].
Aided- and self-assembly of liquid crystalline nanoparticles in bulk and in solution: computer simulation studies
Published in Liquid Crystals, 2023
A. Slyusarchuk, D. Yaremchuk, J. Lintuvuori, M. R. Wilson, M. Grenzer, S. Sokołowski, J. Ilnytskyi
The structure of the self-assembled morphology is defined by the type of the core nanoparticle (metal/non-metal, magnetic/non-magnetic, etc.); grafting density, length, flexibility and chemical details of ligands; number and type of functionalisation groups and decoration pattern [5–10]. The prerequisite for self-assembly to occur is the presence of external conditions, such as temperature, pressure/density, properties of a solvent, presence of surfaces or reaction to an external field. The prediction of the symmetry/structure/properties of self-assembled morphologies that depend on all these factors, is immensely challenging.