Raspberry-like nanocomposite microsphere via Double In situ miniemulsion polymerization using interfacial redox initiator system

2012 ◽  
Vol 21 (2) ◽  
pp. 123-126 ◽  
Author(s):  
Beibei Yang ◽  
Jianan Zhang ◽  
Jizhi Lin ◽  
Bo Wu ◽  
Qing Liu ◽  
...  
2014 ◽  
Vol 31 (4) ◽  
pp. 925-933 ◽  
Author(s):  
M. M. E. Colmán ◽  
D. L. Chicoma ◽  
R. Giudici ◽  
P. H. H. Araújo ◽  
C. Sayer

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Gamal A. El Mahdy ◽  
Ayman M. Atta ◽  
Amro K. F. Dyab ◽  
Hamad A. Al-Lohedan

New method was used to prepare magnetite nanoparticle based on reduction of Fe(III) ions with potassium iodide to produce Fe3O4nanoparticle. The prepared magnetite was stabilized with cross-linked polymer based on 2-acrylamido-2-methylpropane sulfonic acid (AMPS to prepare novel core-shell nanogel. In this respect, Fe3O4/poly(2-acrylamido-2-methylpropane sulfonic acid) (PAMPS) magnetic nanogels with controllable particle size produced via free aqueous polymerization at 65°C have been developed for the first time. The polymer was crosslinked in the presence of N,N-methylenebisacrylamide (MBA) as a crosslinker and potassium peroxydisulfate (KPS) as redox initiator system. The structure and morphology of the magnetic nanogel were characterized by Fourier transform infrared spectroscopy (FTIR) and transmission and scanning electron microscopy (TEM and SEM). The effectiveness of the synthesized compounds as corrosion inhibitors for carbon steel in 1 M HCl was investigated by various electrochemical techniques such as potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The results showed enhancement in inhibition efficiencies with increasing the inhibitor concentrations. The results showed that the nanogel particles act as mixed inhibitors. EIS data revealed thatRctincreases with increasing inhibitor concentration.


2019 ◽  
Vol 10 ◽  
pp. 522-530 ◽  
Author(s):  
Kartheek Katta ◽  
Dmitry Busko ◽  
Yuri Avlasevich ◽  
Katharina Landfester ◽  
Stanislav Baluschev ◽  
...  

We report the synthesis of high-performance organic–inorganic hybrid fluorescent nanocapsules comprising a polymer shell armored with an inorganic layer and a liquid core containing a fluorophore. The polymeric capsules are synthesized by free radical miniemulsion polymerization and contain covalently bound carboxylate surface functionalities that allow for the binding of metal ions through electrostatic interaction. A cerium(IV) oxide nanoparticle layer, formed in situ at the surface of the hybrid nanocapsules, acts as oxygen scavenger and keeps external reactive molecular oxygen from entering into the capsules, eventually resulting in a reduction of the photooxidation of encapsulated fluorescent molecules. This approach shows an increase in the fluorescence of the model organic fluorophore terrylene diimide by avoiding the ground-state molecular oxygen to react with electronically excited states of the fluorescent hydrocarbon molecule.


2013 ◽  
Vol 4 (5) ◽  
pp. 1459-1466 ◽  
Author(s):  
Jianan Zhang ◽  
Shuilai Qiu ◽  
Yulu Zhu ◽  
Zhengqi Huang ◽  
Beibei Yang ◽  
...  

2017 ◽  
Vol 8 ◽  
pp. 1328-1337 ◽  
Author(s):  
Bertha T Pérez-Martínez ◽  
Lorena Farías-Cepeda ◽  
Víctor M Ovando-Medina ◽  
José M Asua ◽  
Lucero Rosales-Marines ◽  
...  

Film forming, stable hybrid latexes made of methyl metacrylate (MMA), butyl acrylate (BA) and 2-hydroxyethyl methacrylate (HEMA) copolymer reinforced with modified multiwalled carbon nanotubes (MWCNTs) were synthesized by in situ miniemulsion polymerization. The MWCNTs were pretreated by an air sonication process and stabilized by polyvinylpyrrolidone. The presence of the MWCNTs had no significant effect on the polymerization kinetics, but strongly affected the polymer characteristics (T g and insoluble polymer fraction). The performance of the in situ composites was compared with that of the neat polymer dispersion as well as with those of the polymer/MWCNT physical blends. The in situ composites showed the presence of an additional phase likely due to the strong interaction between the polymer and MWNCTs (including grafting) that reduced the mobility of the polymer chains. As a result, a substantial increase of both the storage and the loss moduli was achieved. At 60 °C, which is above the main transition region of the polymer, the in situ composites maintained the reinforcement, whereas the blends behaved as a liquid-like material. This suggests the formation of a 3D network, in good agreement with the high content of insoluble polymer in the in situ composites.


2012 ◽  
Vol 7 (1) ◽  
pp. 54-63 ◽  
Author(s):  
Laís B. Fonseca ◽  
Márcio Nele ◽  
Nádia Maria Volpato ◽  
Rafael C. Seiceira ◽  
José Carlos Pinto

2006 ◽  
Vol 2006 ◽  
pp. 1-10 ◽  
Author(s):  
Bérangère Bailly ◽  
Anne-Carole Donnenwirth ◽  
Christèle Bartholome ◽  
Emmanuel Beyou ◽  
Elodie Bourgeat-Lami

Polystyrene (PS) chains with molecular weights comprised between 8000 and 64000g⋅mol-1and narrow polydispersities were grown from the surface of silica nanoparticles (Aerosil A200 fumed silica and Stöber silica, resp.) through nitroxide-mediated polymerization (NMP). Alkoxyamine initiators based on N-tert-butyl-1-diethylphosphono-2,2-dimethylpropyl nitroxide (DEPN) and carrying a terminal functional group have been synthesized in situ and grafted to the silica surface. The resulting grafted alkoxyamines have been employed to initiate the growth of polystyrene chains from the inorganic surface. The maximum grafting density of the surface-tethered PS chains was estimated and seemed to be limited by initiator confinement at the interface. Then, the PS-grafted Stöber silica nanoparticles were entrapped inside latex particles via miniemulsion polymerization. Transmission electron microscopy indicated the successful formation of silica-polystyrene core-shell particles.


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