scholarly journals Facile TEMPO Immobilization onto Poly(acrylic acid)-Modified Magnetic Nanoparticles: Preparation and Property

2017 ◽  
Vol 2017 ◽  
pp. 1-8
Author(s):  
Guohui Huang ◽  
Xiaoxuan Liu ◽  
Yiling Bei ◽  
Huiqing Ma
Keyword(s):  
Magnetic Nanoparticles ◽  
Acrylic Acid ◽  
Polymer Chain ◽  
Magnetic Particles ◽  
Esterification Reaction ◽  
Catalyst Recycling ◽  
Simple Method ◽  
Nanocomposite Catalyst ◽  
Modified Magnetic Nanoparticles ◽  
Poly Acrylic Acid

Adding catalysts to magnetic polyvalent supports facilitating catalyst recycling and recovery seems feasible. Polymer-modified magnetic nanocomposites for organocatalyst immobilization are a plausible approach to this technology. Here, we present facile and efficient method for 2,2′,6,6′-tetramethylpiperidinyl-1-oxy (TEMPO) immobilization onto polymer-modified magnetic nanoparticles under mild reaction conditions. Poly(acrylic acid) was chosen to graft from magnetic nanoparticle through a simple inverse emulsion polymerization technique. The resulting poly(acrylic acid) magnetic nanocomposite is an ideal material to immobilize the organocatalyst 4-hydroxy-2,2′,6,6′-tetramethylpiperidinyl-1-oxy (H-TEMPO) via an esterification reaction with pendant carboxyl group on the polymer chain. Instrumental analysis confirmed that poly(acrylic acid) chain was grafted on the silica-coated magnetic particles by this simple method while maintaining their magnetic properties; elemental analysis indicated that TEMPO was efficiently immobilized onto the polymer chain. The catalysis tests under both Anelli and Minisci system showed that the nanocomposite catalyst exhibits proper selectivity and activity for the alcohol/aldehyde transformation. Recycling experiments showed that stability and reusability of the nanocomposite catalyst were satisfying.

UV crosslinked poly(acrylic acid): a simple method to bio-functionalize electrolyte-gated OFET biosensors

2015 ◽  
Vol 3 (25) ◽  
pp. 5049-5057 ◽  
Author(s):  
M. Y. Mulla ◽  
P. Seshadri ◽  
L. Torsi ◽  
K. Manoli ◽  
A. Mallardi ◽  
...  
Keyword(s):  
Acrylic Acid ◽  
Organic Semiconductor ◽  
Simple Method ◽  
Acid Coating ◽  
Poly Acrylic Acid

A sensitive EGOFET biosensor fabricated by anchoring bioprobes through a UV crosslinked poly(acrylic acid) coating deposited on an organic semiconductor.

Large-scale synthesis and characterization of magnetic poly(acrylic acid) nanogels via miniemulsion polymerization

RSC Advances ◽  
2015 ◽  
Vol 5 (72) ◽  
pp. 58889-58894 ◽  
Author(s):  
Jianan Zhang ◽  
Zhengquan Lu ◽  
Mingyuan Wu ◽  
Qingyun Wu ◽  
Jianjun Yang
Keyword(s):  
Magnetic Nanoparticles ◽  
Acrylic Acid ◽  
Large Scale ◽  
Miniemulsion Polymerization ◽  
Synthesis And Characterization ◽  
Large Scale Preparation ◽  
Scale Preparation ◽  
Large Scale Synthesis ◽  
Poly Acrylic Acid

A facile method for the large-scale preparation of poly(acrylic acid) (PAA) nanogels was reported by miniemulsion polymerization. After the encapsulation of magnetic nanoparticles, magnetic PAA nanogels were fabricated successfully.

Spectroscopic and Electronic Properties of Layer-by-Layer Assembled Gamma-Irradiated Silver/Poly(Acrylic Acid) Nanocomposites

2015 ◽  
Vol 1098 ◽  
pp. 19-24 ◽  
Author(s):  
Ken Aldren S. Usman ◽  
Lawrence John Paulo L. Trinidad ◽  
Leon M. Payawan
Keyword(s):  
Thin Films ◽  
Acrylic Acid ◽  
Electronic Properties ◽  
Indium Tin Oxide ◽  
Layer By Layer ◽  
Simple Method ◽  
Silica Surfaces ◽  
Vis Spectroscopy ◽  
Gamma Irradiated ◽  
Poly Acrylic Acid

Layer-by-layer (L-b-L) assembly is a simple method that is useful in immobilizing nanomaterials into thin films. However, the retention of the optical and photogalvanic property of the nanoparticles and the functionalization of these materials are the common issues raised regarding this technique. In this study, L-b-L thin films were prepared from γ-radiation reduced,silver/poly (acrylic acid) nanocomposites (Ag/PAA). Negatively surface charged nanocomposites were immobilized on different silica surfaces, namely quartz, Indium Tin Oxide-modified glass and ordinary glass. Characterization of the solution and bound form of the nanocomposites were done to evaluate the retention of their novel properties. The size distribution of the solution-phased Ag/PAA was assessed using dynamic light scattering (DLS). The surface morphology, spectroscopic and electronic properties of the multilayer films were characterized using atomic force microscopy (AFM), scanning electron microscopy (SEM), UV-vis spectroscopy, surface plasmon resonance (SPR) and cyclic voltammetry (CV).

Self-Assembly and Graft Polymerization Route to Monodispersed Fe3O4@SiO2—Polyaniline Core–Shell Composite Nanoparticles: Physical Properties

2008 ◽  
Vol 8 (11) ◽  
pp. 5632-5639 ◽  
Author(s):  
Kakarla Raghava Reddy ◽  
Kwang-Pill Lee ◽  
Ju Young Kim ◽  
Youngil Lee
Keyword(s):  
Magnetic Nanoparticles ◽  
Self Assembly ◽  
Magnetic Particles ◽  
Graft Polymerization ◽  
Photoelectron Spectra ◽  
Core Shell ◽  
X Ray ◽  
Pl Spectra ◽  
The Core ◽  
Modified Magnetic Nanoparticles

This study describes the synthesis of monodispersed core–shell composites of silica-modified magnetic nanoparticles and conducting polyaniline by self-assembly and graft polymerization. Magnetic ferrite nanoparticles (Fe3O4) were prepared by coprecipitation of Fe+2 and Fe+3 ions in alkaline solution, and then silananized. The silanation of magnetic particles (Fe3O4@SiO2) was carried out using 3-bromopropyltrichlorosilane (BPTS) as the coupling agent. FT-IR spectra indicated the presence of Fe—O—Si chemical bonds in Fe3O4@SiO2. Core–shell type nanocomposites (Fe3O4@SiO2/PANI) were prepared by grafting polyaniline (PANI) on the surface of silanized magnetic particles through surface initiated in-situ chemical oxidative graft polymerization. The nanocomposites were characterized by high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), X-ray photoelectron spectra (XPS), Fourier transform infrared (FTIR) spectra, UV-visible spectroscopy, photoluminescence (PL) spectra, electrical conductivity and magnetic characteristics. HRTEM images of the nanocomposites revealed that the silica-modified magnetic particles made up the core while PANI made up the shell. The XPS spectrum revealed the presence of silica in the composites, and the XRD results showed that the composites were more crystalline than pure PANI. PL spectra show that composites exhibit photoluminescent property. Conductivity of the composites (6.2 to 9.4 × 10−2 S/cm) was higher than that of pristine PANI (3.7 × 10−3 S/cm). The nanocomposites exhibited superparamagnetism. Formation mechanism of the core–shell structured nanocomposites and the effect of modified magnetic nanoparticles on the electro-magnetic properties of the Fe3O4@SiO2/PANI nanocomposites are also investigated. This method provides a new strategy for the generation of multi-functional nanocomposites that composed of other conducting polymers and metal nanoparticles.

Soft ionic liquid based resistive memory characteristics in a two terminal discrete polydimethylsiloxane cylindrical microchannel

2020 ◽  
Vol 8 (38) ◽  
pp. 13368-13374
Author(s):  
Muhammad Umair Khan ◽  
Gul Hassan ◽  
Jinho Bae
Keyword(s):  
Ionic Liquid ◽  
Acrylic Acid ◽  
Sodium Hydroxide ◽  
Sodium Salt ◽  
Resistive Memory ◽  
Cylindrical Microchannel ◽  
Memory Characteristics ◽  
Poly Acrylic Acid

This paper proposes a novel soft ionic liquid (IL) electrically functional device that displays resistive memory characteristics using poly(acrylic acid) partial sodium salt (PAA-Na+:H2O) solution gel and sodium hydroxide (NaOH) in a thin polydimethylsiloxane (PDMS) cylindrical microchannel.

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