Analysis of gallium nitride-based optical microring resonator with doped polymer grafting material

<p>In this paper, the Gallium nitride-based optical microring resonator (OMR) filter with polymer grafting material (PMMA) coating was designed and optimized to predict its potential as a wavelength filtering device. The optimization was focused on the design parameters such as polymer thickness, gap separation variation, and the bus and ring waveguide widths. The target is to achieve the best output in terms of insertion loss (IL) and Extinction Ratio for wavelength-division multiplexing (WDM) applications, specifically for the use of the C-Band network. Upon completion, it was found that the optimized design was a ring radius of 10 μm and PMMA thickness of 0.055 μm, with the bus waveguide width of 800 nm and the output bus waveguide of 800 nm giving the observed IL of 0.07 dB and 87.3% extinction rate.</p>

Synthesis and Characterization of Pyridine-Grafted Copolymers of Acrylic Acid–Styrene Derivatives for Antimicrobial and Fluorescence Applications

The goal of the present study was to copolymerize 3-(4-acetylphenylcarbamoyl) acrylic acid and styrene using azo-bis-isobutyronitrile (AIBN) as a catalyst. The resulting copolymers exhibited number average molecular weights (Mn) of 3.73–5.23 × 104 g/mol with a variable polydispersity (PDI = 2.3–3.8). The amide group of the PMA/PSA polymer was used for grafting poly (-styrene-maleic acid substituted aromatic 2-aminopyridine) by the Hantzsch reaction using a substituted aromatic aldehyde, malononitrile, and ammonium acetate. The polymer can emit strong blue fluorescence (λ = 510 nm) and its thermal stability and solubility were enhanced by polymer grafting. Moreover, the polymer showed the fluorescence spectra of the copolymer had a strong, broad emission band between 300 to 550 nm (maximum wavelength 538 nm) under excitation at 293 nm. The Hantzsch reaction yields an interesting class of nitrogen-based heterocycles that combine with a synthetic strategy for synthesis of grafted co-polymer pyridine-styrene derivatives. The as-prepared pyridine-based polymer compounds were screened against Gram-positive and Gram-negative bacteria, where a maximum inhibition zone toward all four types of bacteria was observed, including specific antifungal activity. Herein, a series of pyridine compounds were synthesized that showed enhanced fluorescent properties and antimicrobial properties due to their unique structure and ability to form polymer assemblies.

Advances in polyaniline for biomedical applications

: Conducting polymers are an outstanding class of materials characterized by electroconducting properties that make them good candidates for applications in several sectors. Among them, polyaniline (PANI) is unique for its extraordinary ability to conduct electricity, biocompatibility and low toxicity. In spite of its surprising features, to date PANI have not yet found application in the practical uses, because of its low solubility and processability. In order to overcome these limitations, different approaches have been developed, such as polymer grafting processes, PANI-based composites and blends preparation. The present review describes the most recent advances on PANI applications in biomedical fields, such as antioxidant, antimicrobial and antivirus activity, drug delivery, cancer therapy, etc. A look to the synthetic procedures is also reported because it is crucial for the realization of more innovative materials in the next future.

A Review on the Synthesis, Characterization, and Modeling of Polymer Grafting

A critical review on the synthesis, characterization, and modeling of polymer grafting is presented. Although the motivation stemmed from grafting synthetic polymers onto lignocellulosic biopolymers, a comprehensive overview is also provided on the chemical grafting, characterization, and processing of grafted materials of different types, including synthetic backbones. Although polymer grafting has been studied for many decades—and so has the modeling of polymer branching and crosslinking for that matter, thereby reaching a good level of understanding in order to describe existing branching/crosslinking systems—polymer grafting has remained behind in modeling efforts. Areas of opportunity for further study are suggested within this review.

Controlling nanostructure and mechanical properties in triblock copolymer/monomer blends via reaction-induced phase transitions

In situ polymer grafting from the mid-block of an ABA triblock copolymer leads to morphology transitions and enhanced mechanical properties.