Engineering of silver nanoparticle fabricated poly (N-isopropylacrylamide-co-acrylic acid) microgels for rapid catalytic reduction of nitrobenzene

2016 ◽  
Vol 36 (1) ◽  
pp. 87-96 ◽  
Author(s):  
Zahoor H. Farooqi ◽  
Khalida Naseem ◽  
Aysha Ijaz ◽  
Robina Begum
Keyword(s):  
Acrylic Acid ◽  
Rate Constant ◽  
Apparent Rate Constant ◽  
Reduction Method ◽  
Catalytic Reduction ◽  
Visible Spectroscopy ◽  
Uv Visible ◽  
Polymerization Method ◽  
Hybrid Microgels

Abstract Three different poly(N-isopropylacrylamide-co-acrylic acid) [p(NIPAM-AA)] microgel samples were prepared using a precipitation polymerization method by varying the concentration of NIPAM and AA in aqueous medium. The microgels were used as microreactors to fabricate Ag nanoparticles (NPs) by in situ a reduction method. Fourier transform infrared (FTIR) and UV-visible spectroscopy were used to characterize the pure and hybrid microgels. The hybrid microgels with different AA content were used as catalysts for reduction of nitrobenzene (NB) into aniline. The progress of the reaction was monitored by a UV-visible spectrophotometer. The results show that the value of the apparent rate constant for catalytic reduction of NB decreases from 0.431 min-1 to 0.227 min-1 by increasing AA content from 3 mol% to 7 mol%, respectively. Decrease in apparent rate constant with increase of AA content can be attributed to an increase in hydrophilicity with increase of AA contents of the microgels. The increase in induction period with increase of AA contents indicates that diffusion of NB towards the catalytic surface becomes difficult due to an increase of hydrophilicity.

scholarly journals Synthesis, characterization and fabrication of copper nanoparticles in N-isopropylacrylamide based co-polymer microgels for degradation of p-nitrophenol

2015 ◽  
Vol 33 (1) ◽  
pp. 185-192 ◽  
Author(s):  
Zahoor H. Farooqi ◽  
Tanzila Sakhawat ◽  
Shanza Rauf Khan ◽  
Farah Kanwal ◽  
Muhammad Usman ◽  
...  
Keyword(s):  
Acrylic Acid ◽  
Aqueous Medium ◽  
Copper Nanoparticles ◽  
Catalytic Reduction ◽  
Copper Ions ◽  
Effect Of Temperature ◽  
Ft Ir ◽  
Catalyst Dosage ◽  
Hybrid Microgels

AbstractPoly(N-isopropylacrylamide-co-acrylic acid) [P(NIPAM-co-AAc)] microgels were synthesized by precipitation polymerization. Copper nanoparticles were successfully fabricated inside the microgels by in-situ reduction of copper ions in an aqueous medium. The microgels were characterized by Fourier Transform Infrared Spectroscopy (FT-IR) and Dynamic Light Scattering (DLS). Hydrodynamic radius of P(NIPAM-co-AAc) microgel particles increased with an increase in pH in aqueous medium at 25 °C. Copper-poly(N-isopropylacrylamide-co-acrylic acid) [Cu-P(NIPAM-co-AAc)] hybrid microgels were used as a catalyst for the reduction of 4-nitrophenol (4-NP). Effect of temperature, concentration of sodium borohydride (NaBH4) and catalyst dosage on the value of apparent rate constant (kapp) for catalytic reduction of 4-NP in the presence of Cu-P(NIPAM-co-AAc) hybrid microgels were investigated by UV-Vis spectrophotometry. It was found that the value of kapp for catalytic reduction of 4-NP in the presence of Cu-P(NIPAM-co-AAc) hybrid microgel catalyst increased with an increase in catalyst dosage, temperature and concentration of NaBH4 in aqueous medium. The results were discussed in terms of diffusion of reactants towards catalyst surface and swelling-deswelling of hybrid microgels.

In Situ Polymerization and Characterization of Poly(ε-caprolactone)/Layered Double Hydroxide Nanocomposites

2012 ◽  
Vol 557-559 ◽  
pp. 371-374
Author(s):  
Lian Liu ◽  
Teng Yu ◽  
Pei Wang ◽  
Guang Shuo Wang
Keyword(s):  
Layered Double Hydroxide ◽  
In Situ Polymerization ◽  
X Ray Diffraction ◽  
Visible Spectroscopy ◽  
X Ray ◽  
Uv Visible ◽  
Absorbance Peak ◽  
Double Hydroxide

Nanocomposites of poly(ε-caprolactone) (PCL) and layered double hydroxide (LDH) were prepared by in situ polymerization at low LDHs loadings in this work. The resultants were characterized by FTIR spectroscopy, X-ray diffraction (XRD), differential scanning calorimeter (DSC) and UV-visible spectroscopy (UV-vis). FTIR showed that the PCL/LDHs nanocomposites were prepared successfully by in situ polymerization and XRD spectra showed that the crystal structure did not change greatly in the presence of LDHS. DSC results confirmed that LDHs could act as nucleating agents. UV-vis spectra showed that LDHs had stronger absorbance peak than LDH. Moreover, the PCL/LDHs nanocomposites had strong anti-ultraviolet effect by introduction of LDHs into polymer matrix.

scholarly journals Extent of Reduction of Vanadium Oxides during Catalytic Oxidation of Alkanes Measured by in-Situ UV−Visible Spectroscopy

2004 ◽  
Vol 108 (7) ◽  
pp. 2345-2353 ◽  
Author(s):  
Morris D. Argyle ◽  
Kaidong Chen ◽  
Carlo Resini ◽  
Catherine Krebs ◽  
Alexis T. Bell ◽  
...  
Keyword(s):  
Catalytic Oxidation ◽  
Vanadium Oxides ◽  
Visible Spectroscopy ◽  
Uv Visible

scholarly journals Green Synthesis of Silver Nanoparticles using Polyalthia longifolia Stem Bark Extract and its Catalytic Reduction of 4-Nitrophenol

2019 ◽  
Vol 31 (11) ◽  
pp. 2439-2442
Author(s):  
Karuppiah Muthu ◽  
B. Akilandaeaswari ◽  
S. Mangala Nagasundari
Keyword(s):  
Silver Nanoparticles ◽  
Green Synthesis ◽  
Catalytic Reduction ◽  
Stem Bark ◽  
Bark Extract ◽  
Visible Spectroscopy ◽  
Transmission Electron ◽  
Stem Bark Extract ◽  
Uv Visible ◽  
Polyalthia Longifolia

In this present study, green synthesis of silver nanoparticles (AgNPs) was synthesized from silver nitrate using the reducing agents of Polyalthia longifolia bark extract and applied the catalyst in the reduction/degradation of environmental polluted organic compound in the presence of NaBH4. Initially, the colourless reaction mixture was slowly changed to yellowish brown, UV-visible spectroscopy of surface plasmon resonance centre at 447 nm confirmed the formation of AgNPs. High resolution transmission electron microscopy (HRTEM) clearly identified the spherical shapes nanoparticles with diameters sizes 5-25 nm. This AgNPs has excellent catalyst in the catalytic reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) as compared to the reducing agent of NaBH4 (chemical) and plant extract (natural).

Facile fabrication of poly(acrylic acid) hollow nanogels via in situ Pickering miniemulsion polymerization

2015 ◽  
Vol 6 (34) ◽  
pp. 6125-6128 ◽  
Author(s):  
Jianan Zhang ◽  
Zhengquan Lu ◽  
Mingyuan Wu ◽  
Qingyun Wu ◽  
Jianjun Yang
Keyword(s):  
Acrylic Acid ◽  
Liquid Core ◽  
Miniemulsion Polymerization ◽  
Facile Fabrication ◽  
Polymerization Method ◽  
Hydrophobic Solvent ◽  
Poly Acrylic Acid

We report herein a facile and large fabrication of PAA hollow nanogels via an in situ Pickering miniemulsion polymerization method by using a hydrophobic solvent as the liquid core.

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