Synthesis and characterization of p(NIPAM-AA-AAm) microgels for tuning of optical Properties of silver nanoparticles

Naeem, Hina; Farooqi, Zahoor H.; Shah, Luqman Ali; Siddiq, Muhammad

doi:10.1007/s10965-012-9950-1

Cited by 56 publications

(29 citation statements)

References 41 publications

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“…They are enormously used in the field of catalysis (1)(2)(3)(4)(5), magnetic resonance imaging (6), environmental remediation (7), medicine (8,9), cosmetics (10) and biosensing (11) due to their quantum size-related properties. The catalytic applications of nanoparticles of expensive metals such as gold (1,12), silver (2,3,13), platinum (14)(15)(16) and palladium (17)(18)(19)(20) are mostly studied because they are stable under different environmental conditions and do not oxidize to their oxides easily. Contrary to this, there are some coinage metal-based nanoparticles [such as zinc (21), copper (22,23), nickel (Ni) (24) and cobalt (Co) (25) whose catalytic applications have not been enormously studied so far, because they are less stable.…”

Section: Introductionmentioning

confidence: 99%

Cobalt and nickel nanoparticles fabricated p(NIPAM-co-MAA) microgels for catalytic applications

et al. 2014

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Abstract:In this research work, multi-responsive poly(Nisopropylacrylamide-co-methacrylic acid) copolymer microgels were synthesized via emulsion polymerization in aqueous medium. Then, nickel and cobalt nanoparticles were fabricated within these microgels by in situ reduction of metal ions using sodium borohydride (NaBH 4 ) as a reducing agent. Fourier transform infrared spectroscopy was used to characterize these microgels. The pH sensitivity of these copolymer microgels was studied using dynamic light scattering technique (DLS). DLS studies revealed that the hydrodynamic radius of these microgels increased with the increase in pH of the medium at 25°C. The catalytic activity of hybrid microgels for the reduction of p-nitrophenol (4-NP) to p-aminophenol (4-AP) was investigated by UV-visible spectrophotometery. The value of apparent rate constant of reaction was found to change linearly with catalyst dosage. The nickel-based hybrid system was found to be five times more efficient as a catalyst compared to the cobalt-based hybrid system for the reduction of 4-NP to 4-AP in aqueous medium.

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Section: Introductionmentioning

confidence: 99%

Cobalt and nickel nanoparticles fabricated p(NIPAM-co-MAA) microgels for catalytic applications

et al. 2014

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“…No aggregation was observed for both compositions at high temperature up to 50°C, which was confirmed by the presence of some charge on the surface of particles at low pH calculated from zeta potential values shown in Table 1. However, aggregation of particles at low pH and high temperature was reported for acrylic acid (AA) in a previous study [22]. At pH 8.36, the strong electrostatic repulsive forces shifted the VPTT to a higher values and only a slight decrease in particle size was observed at 50°C (Fig.…”

Section: Sensitive Behavior Of Microgelsmentioning

confidence: 65%

“…The synthesis of p(NIPAM-co-MAA) copolymer microgels was carried out by free radical emulsion polymerization reported in the literature [22] with slight modification. Typically, the required amount of monomers NIPAM and MAA (listed in Table 1), 84.7 mg of BIS and 57 mg of SDS were dissolved in 100 mL of deionized water and stirred for 1 h. The mixture was purged with nitrogen, heated to 65°C, and 5 mL aqueous solution of APS (65 mg/5 mL) was added for initiation.…”

Section: Synthesis Of P(nipam-co-maa) Copolymer Microgelsmentioning

confidence: 99%

Fabrication of Ag and Au nanoparticles in cross-linked polymer microgels for their comparative catalytic study

Shah

Sayed

Siddiq

2017

Materials Science-Poland

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Three dimensional cross-linked polymer microgels with temperature responsive N-isopropyl acrylamide (NIPAM) and pH sensitive methacrylic acid (MAA) were successfully synthesized by free radical emulsion polymerization with different amounts of MAA. Silver and gold nanoparticles with the size of 6.5 nm and 3.5 nm (±0.5 nm), respectively were homogeneously reduced inside these materials by chemical reduction method at pH 2.78 and 8.36 for the preparation of hybrid materials. The samples were characterized by FT-IR, DLS and TEM techniques. The catalytic activity of the hybrid materials was investigated for the reduction of 4-nitrophenol (4-NP) using NaBH 4 as reducing agent by UV-Vis spectroscopy. The hybrid polymer network synthesized at pH 8.36 showed enhanced catalytic efficiency compared to the catalysts synthesized at pH 2.78. In this study, it has been stated that the catalyst activity strongly depends on the amount of MAA, pH value during synthesis and the type of entrapped metal nanoparticles.

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“…Absorption bands around 1558.48, 1658.78 and 3360.0 cm −1 were also observed which, respectively, indicates incorporation of -CH 2 , C=O and N-H (stretching) groups within the structure of the synthesized p(NIPAM-co-MAAc) microgels. Absorption band of N-H bond is broad which indicates the presence of bonded water molecules within the microgels [26]. Luo et al [37] used FT-IR technique to analyze the structure of poly(N-isopropylacrylamide-coacrylic acid) and poly(N-isopropylacrylamide-co-40-aminobenzo-18-crown-6) microgels.…”

Section: Ft-ir Analysis Of Poly(n-isopropylacrylamide-co-methacrylic mentioning

confidence: 99%

“…Moreover, microgels are sensitive to pH, temperature and ionic strength. Therefore, they can tune the catalytic activity of Cu nanoparticles in response to variable pH, temperature and ionic strength [25][26][27][28].…”

Section: Introductionmentioning

confidence: 99%

Poly(N-isopropylacrylamide-co-methacrylic acid) microgel stabilized copper nanoparticles for catalytic reduction of nitrobenzene

Farooqi

Butt

Begum

et al. 2015

Materials Science-Poland

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Poly(N-isopropylacrylamide-co-methacrylic acid) microgels [p(NIPAM-co-MAAc)] were synthesized by precipitation polymerization of N-isopropylacrylamide and methacrylic acid in aqueous medium. These microgels were characterized by dynamic light scattering and Fourier transform infrared spectroscopy. These microgels were used as micro-reactors for in situ synthesis of copper nanoparticles using sodium borohydride (NaBH 4 ) as reducing agent. The hybrid microgels were used as catalysts for the reduction of nitrobenzene in aqueous media. The reaction was performed with different concentrations of catalyst and reducing agent. A linear relationship was found between apparent rate constant (k app ) and amount of catalyst. When the amount of catalyst was increased from 0.13 to 0.76 mg/mL then k app was increased from 0.03 to 0.14 min −1 . Activation parameters were also determined by performing reaction at two different temperatures. The catalytic process has been discussed in terms of energy of activation, enthalpy of activation and entropy of activation. The synthesized particles were found to be stable even after 14 weeks and showed catalytic activity for the reduction of nitrobenzene.

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Synthesis and characterization of p(NIPAM-AA-AAm) microgels for tuning of optical Properties of silver nanoparticles

Cited by 56 publications

References 41 publications

Cobalt and nickel nanoparticles fabricated p(NIPAM-co-MAA) microgels for catalytic applications

Cobalt and nickel nanoparticles fabricated p(NIPAM-co-MAA) microgels for catalytic applications

Fabrication of Ag and Au nanoparticles in cross-linked polymer microgels for their comparative catalytic study

Poly(N-isopropylacrylamide-co-methacrylic acid) microgel stabilized copper nanoparticles for catalytic reduction of nitrobenzene

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