Thermal, Thermo-mechanical, and Dielectric Characterization Tools for Polymers and Multicomponent Polymeric Systems

2019 ◽  
pp. 1-10
Author(s):  
Jose James ◽  
K.P. Pramoda ◽  
Sabu Thomas
Keyword(s):  
Polymeric Systems ◽  
Dielectric Characterization

Microwave dielectric characterization of bulk ferroelectrics

1998 ◽  
Vol 08 (PR9) ◽  
pp. Pr9-113-Pr9-116 ◽  
Author(s):  
C. M. Weil ◽  
R. G. Geyer ◽  
L. Sengupta
Keyword(s):  
Dielectric Characterization ◽  
Microwave Dielectric

Novel organic, polymeric materials for electronics applications

2002 ◽  
Vol 722 ◽  
Author(s):  
Ram W. Sabnis ◽  
Mary J. Spencer ◽  
Douglas J. Guerrero
Keyword(s):  
Optical Density ◽  
Chemical Vapor ◽  
Polymeric Materials ◽  
Substantial Improvement ◽  
Polymeric Systems ◽  
Patterned Wafers ◽  
Visible Spectra ◽  
Potential Applications ◽  
Deep Ultraviolet ◽  
Deposited Films

AbstractNovel organic, polymeric materials and processes of depositing thin films on electronics substrates by chemical vapor deposition (CVD) have been developed and the lithographic behavior of photoresist coated over these CVD films at deep ultraviolet (DUV) wavelength has been evaluated. The specific monomers synthesized for DUV applications include [2.2](1,4)- naphthalenophane, [2.2](9,10)-anthracenophane and their derivatives which showed remarkable film uniformity on flat wafers and conformality over structured topography wafers, upon polymerization by CVD. The chemical, physical and optical properties of the deposited films have been characterized by measuring parameters such as thickness uniformity, solubility, conformality, adhesion to semiconductor substrates, ultraviolet-visible spectra, optical density, optical constants, defectivity, and resist compatibility. Scanning electron microscope (SEM) photos of cross-sectioned patterned wafers showed verticle profiles with no footing, standing waves or undercut. Resist profiles down to 0.10 νm dense lines and 0.09 νm isolated lines were achieved in initial tests. CVD coatings generated 96-100% conformal films, which is a substantial improvement over commercial spin-on polymeric systems. The light absorbing layers have high optical density at 248 nm and are therefore capable materials for DUV lithography applications. CVD is a potentially useful technology to extend lithography for sub-0.15 νm devices. These films have potential applications in microelectronics, optoelectronics and photonics.

Biopolymers with Medical Applications Optimized method for obtaining chitosan-based delivery systems

2018 ◽  
Vol 69 (7) ◽  
pp. 1756-1759 ◽  
Author(s):  
Luminita Confederat ◽  
Iuliana Motrescu ◽  
Sandra Constantin ◽  
Florentina Lupascu ◽  
Lenuta Profire
Keyword(s):  
Drug Delivery ◽  
Drug Delivery Systems ◽  
Average Diameter ◽  
Delivery Systems ◽  
Cross Linking ◽  
Low Molecular Weight ◽  
Polymeric Systems ◽  
Chitosan Microparticles ◽  
Degree Of Swelling

The aim of this study was to optimize the method used for obtaining microparticles based on chitosan � a biocompatible, biodegradable, and nontoxic polymer, and to characterize the developed systems. Chitosan microparticles, as drug delivery systems were obtained by inotropic gelation method using pentasodiumtripolyphosphate (TPP) as cross-linking agent. Chitosan with low molecular weight (CSLMW) in concentration which ranged between 0.5 and 5 %, was used while the concentration of cross-linking agent ranged between 1 and 5%. The characterization of the microparticles in terms of shape, uniformity and adhesion was performed in solution and dried state. The size of the microparticles and the degree of swelling were also determined. The structure and the morphology of the developed polymeric systems were analyzed by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM).The average diameter of the chitosan microparticles was around 522 �m. The most stable microparticles were obtained using CSLMW 1% and TPP 2% or CSLMW 0.75%and TPP 1%. The micropaticles were spherical, uniform and without flattening. Using CSLMW in concentration of 0.5 % poorly cross-linked and crushed microparticles have been obtained at all TPP concentrations. By optimization of the method, stable chitosan-based micropaticles were obtained which will be used to develop controlled release systems for drug delivery.

Polymeric Systems Based on Derivatives of Ethylene-Vinyl Alcohol Copolymers

2000 ◽  
Vol 15 (3) ◽  
pp. 257-271 ◽  
Author(s):  
W. MARCONI ◽  
S. CORDELLI ◽  
A. NAPOLI ◽  
A. PIOZZI
Keyword(s):  
Vinyl Alcohol ◽  
Ethylene Vinyl Alcohol ◽  
Polymeric Systems ◽  
Derivatives Of

scholarly journals Selective Recognition of Amino Acids and Peptides by Small Supramolecular Receptors

Molecules ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 106
Author(s):  
Joana N. Martins ◽  
João Carlos Lima ◽  
Nuno Basílio
Keyword(s):  
Amino Acids ◽  
Selective Recognition ◽  
Great Promise ◽  
Macrocyclic Compounds ◽  
Synthetic Receptors ◽  
Small Peptides ◽  
Molecular Imprinted Polymers ◽  
Polymeric Systems ◽  
Physiological Conditions ◽  
Level Information

To this day, the recognition and high affinity binding of biomolecules in water by synthetic receptors remains challenging, while the necessity for systems for their sensing, transport and modulation persists. This problematic is prevalent for the recognition of peptides, which not only have key roles in many biochemical pathways, as well as having pharmacological and biotechnological applications, but also frequently serve as models for the study of proteins. Taking inspiration in nature and on the interactions that occur between several receptors and peptide sequences, many researchers have developed and applied a variety of different synthetic receptors, as is the case of macrocyclic compounds, molecular imprinted polymers, organometallic cages, among others, to bind amino acids, small peptides and proteins. In this critical review, we present and discuss selected examples of synthetic receptors for amino acids and peptides, with a greater focus on supramolecular receptors, which show great promise for the selective recognition of these biomolecules in physiological conditions. We decided to focus preferentially on small synthetic receptors (leaving out of this review high molecular weight polymeric systems) for which more detailed and accurate molecular level information regarding the main structural and thermodynamic features of the receptor biomolecule assemblies is available.

scholarly journals A Highly Versatile Polymer Network Based on Liquid Crystalline Dendrimers

2021 ◽  
Vol 22 (11) ◽  
pp. 5740
Author(s):  
Ramón Cervera-Procas ◽  
José-Luis Serrano ◽  
Ana Omenat
Keyword(s):  
Smart Materials ◽  
Liquid Crystalline ◽  
Organic Dyes ◽  
Polymer Network ◽  
Viscoelastic Behavior ◽  
Diverse Range ◽  
Polymeric Systems ◽  
System A ◽  
Porous Microstructure ◽  
Solvent Molecules

Highly functional macromolecules with a well-defined architecture are the key to designing efficient and smart materials, and these polymeric systems can be tailored for specific applications in a diverse range of fields. Herein, the formation of a new liquid crystalline polymeric network based on the crosslinking of dendrimeric entities by the CuI-catalyzed variant of the Huisgen 1,3-dipolar cycloaddition of azides and alkynes to afford 1,2,3-triazoles is reported. The polymeric material obtained in this way is easy to process and exhibits a variety of properties, which include mesomorphism, viscoelastic behavior, and thermal contraction. The porous microstructure of the polymer network determines its capability to absorb solvent molecules and to encapsulate small molecules, like organic dyes, which can be released easily afterwards. Moreover, all these properties may be easily tuned by modifying the chemical structure of the constituent dendrimers, which makes this system a very interesting one for a number of applications.

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