There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

/pdf/self-assembled-monolayers-of-thiolates-on-metals-as-a-form-1neb0hj3k4.pdf

Self-assembled monolayers of thiolates on metals as a form of nanotechnology.

Li-ion battery materials: present and future

Responsive polymer materials can adapt to surrounding environments, regulate transport of ions and molecules, change wettability and adhesion of different species on external stimuli, or convert chemical and biochemical signals into optical, electrical, thermal and mechanical signals, and vice versa. These materials are playing an increasingly important part in a diverse range of applications, such as drug delivery, diagnostics, tissue engineering and 'smart' optical systems, as well as biosensors, microelectromechanical systems, coatings and textiles. We review recent advances and challenges in the developments towards applications of stimuli-responsive polymeric materials that are self-assembled from nanostructured building blocks. We also provide a critical outline of emerging developments.

Emerging applications of stimuli-responsive polymer materials

Microthermomechanical Probing of Thin Composite Polymer Films

Adhesion between abrasive particles and surfaces being polished plays an important role in chemical mechanical planarization (CMP) processes. The changes in particle - surface and particle – particle interactions can significantly influence the effectiveness of material removal and cleaning methods. To determine the adhesion between actual abrasive particles and different surfaces treated by the CMP process a method employing atomic force microscopy (AFM) technique is being developed. The monolayer of silica abrasive nanoparticles was deposited on silicon wafer covered with polymer anchoring layer. High affinity of the thin polymer film to the particles and wafer ensures the stability of particles monolayer on the surface during measurements. AFM cantilever was modified with attachment of 20-40 microns hollow glass bead (representing a flat surface), which then was covered with copper using physical vapor deposition technique. Force-distance curves were collected employing AFM force volume mode and used to calculate the adhesion value. The effect of different factors (such as pH, presence of surfactants) on adhesion between copper surface and silica slurry has been studied.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S194642740009134X

AFM Measurements of Adhesion between CMP Slurry Particles and Copper

INTRODUCTION Smart polymer coatings are of great interest for microelectronic, textile industry, biomedical applications. A possibility to switch and/or precisely tune properties of the coatings by applying external stimuli is the desired advantage of the smart polymer materials to vary, for example, adhesion, wettability, friction, roughness, reactivity, biocompatibility, selectivity, etc. Binary (mixed) polymer brush composed of two incompatible polymers, grafted to a solid substrate, is an example of the smart polymer coating. These two grafted polymers form the brush-like layer of the polymer chains randomly attached by one end to the substrate and stretched in the direction perpendicular to the substrate surface because of the volume excluded effect. Due to the phase segregation the morphology of the mixed brushes is sensitive to surrounding medium. Mixed brushes show the adopting behavior and can be switched between different surface energetic states upon exposure to different solvents. The interaction of the binary polymer brush with selective solvent causes a change of the surface properties of the polymer film because one of the two polymers preferentially occupies a top layer. As well as the surface composition, external stimuli can switch morphology of the film. In this paper we focus on tuning of surface morphologies of polymer coatings prepared from mixed polymer brushes of different molecular weights of grafted chains. We use polystyrene (PS) and poly-2vinyl pyridine (PVP), and PS and polyacrylic acid mixed brushes prepared by “grafting to” method. Additionally, we show that mixed brushes can be prepared from the combination of end-functionalized polymer chains and homopolymer chains grafted in the matrix of the grafted end-functionalized polymer.

/pdf/tuning-morphology-and-surface-properties-of-smart-polymer-l9wird9vam.pdf

Tuning Morphology And Surface Properties Of Smart Polymer Coatings From Mixed Polymer Brushes

Modification of nylon membrane surface with thin polymer layer via "grafting to" approach

Using dissipative particle dynamics, we characterize dynamics of aggregation of molecular bottlebrushes in solvents of various qualities by tracking the number of clusters, the size of the largest cluster, and an average aggregation number. We focus on a low volume fraction of bottlebrushes in a range of solvents and probe three different cutoff criteria to identify bottlebrushes belonging to the same cluster. We demonstrate that the cutoff criteria which depend on both the coordination number and the length of the side chain allows one to correlate the agglomeration status with the structural characteristics of bottlebrushes in solvents of various qualities. We characterize conformational changes of the bottlebrush within the agglomerates with respect to those of an isolated bottlebrush in the same solvents. The characterization of bottlebrush conformations within the agglomerates is an important step in understanding the relationship between the bottlebrush architecture and material properties. An analysis of three distinct cutoff criteria to identify bottlebrushes belonging to the same cluster introduces a framework to identify both short-lived transient and long-lived agglomerates; the same approach could be further extended to characterize agglomerates of various macromolecules with complex architectures beyond the specific bottlebrush architecture considered herein.

/pdf/mesoscale-modeling-of-agglomeration-of-molecular-1e1yorru.pdf

Igor Luzinov

Papers

Microthermomechanical Probing of Thin Composite Polymer Films

AFM Measurements of Adhesion between CMP Slurry Particles and Copper

Tuning Morphology And Surface Properties Of Smart Polymer Coatings From Mixed Polymer Brushes

Modification of nylon membrane surface with thin polymer layer via "grafting to" approach

Mesoscale Modeling of Agglomeration of Molecular Bottlebrushes: Focus on Conformations and Clustering Criteria