scholarly journals Synthesis of Graphene Oxide-Polystyrene Graft Polymer Based on Reversible Addition Fragmentation Chain Transfer and Its Effect on Properties, Crystallization, and Rheological Behavior of Poly (Lactic Acid)

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Li Yang ◽  
Weijun Zhen
Keyword(s):  
Graphene Oxide ◽  
Performance Test ◽  
Chain Transfer ◽  
Loss Modulus ◽  
Molecular Chain ◽  
Grain Structure ◽  
Poly Lactic Acid ◽  
Graft Polymer ◽  
Reversible Addition ◽  
Uniform Dispersion

Graphene oxide-polystyrene graft polymer (SGO-PS) was prepared by reversible addition-fragmentation chain transfer radical polymerization method. Orthogonal experiments indicated that the optimum synthesis reaction conditions for SGO-PS were as follows: the millimole ratio of chain transfer agent to initiator was 0.15 : 0.3, and the amount of styrene was 8 mL at 80°C for 12 hours. The products were characterized by Fourier transform infrared spectroscopy and thermal weightlessness analysis, and the highest grafting rate of SGO-PS was 62.46%. Then, PLA/SGO-PS nanocomposites were prepared using SGO-PS as fillers by melt intercalation method, and its crystallinity, mechanical properties, and thermal stability were significantly improved. Compared with pure PLA, the crystallinity of PLA/SGO-PS (0.3 wt%) nanocomposites was increased by 5 times. Multiple melting behavior tests showed that the introduction of SGO-PS caused the PLA molecular chain to be discharged into the unit cell in time, and the melting temperature shifted to a higher temperature, which ultimately made the grain structure of PLA composites more complete and stable than pure PLA. The rheological performance test showed that the uniform dispersion of SGO-PS in the PLA matrix inhibited the free movement of the PLA molecular chain and caused higher flow resistance, resulting in an increase in the complex viscosity, storage modulus, and loss modulus of PLA/SGO-PS.

scholarly journals Graphene Oxide/L-phenylalanine/polymethacrylamide Nanocomposite as an Efficient Fluorescent Nanosensor for Heavy Metals Detection in Aqueous Media

2021 ◽  
Author(s):  
Mehdi Barzegarzadeh ◽  
Mohammad Sadegh Amini-Fazl ◽  
Seyed Yasin Yazdi-Amirkhiz
Keyword(s):  
Heavy Metals ◽  
Graphene Oxide ◽  
Chain Transfer ◽  
Aqueous Media ◽  
Chemical Properties ◽  
Selective Detection ◽  
Reversible Addition ◽  
Raft Agent ◽  
Ft Ir ◽  
And Chemical Properties

Abstract The application and fabrication of grapheme-based nanomaterials have, caught great attention in the field of sensors in recent years. In this study, a graphene oxide (GO)-based heavy metals nanosensor was prepared via the surface reversible addition-fragmentation chain transfer (RAFT) method. First, GO was prepared from graphene and was modified with L-phenylalanine (LP). Then a RAFT agent was attached chemically into the surface of GO-LP. Next, GO-LP/polymethacrylamide (GO-LP/PMAM) was prepared via the polymerization of methacrylamide (MAM) monomers on the surface of the GO. The surface morphology and chemical properties of the prepared materials were examined by FT-IR, SEM, TGA, UV and PL techniques. The results of PL indicated that the PL intensity of GO-LP/PMAM compared to GO and GO-LP spectra in the water was stronger. Finally, the modified GO was employed as an excellent nanosensor for the selective detection of Cu (II) ions in the range of 0.25-2 mM (correlation coefficient R2 0.9903). Absence any obvious alteration in the fluorescence intensity after the addition of other metal ions indicated the great selectivity for Cu (II). Based on the experimental results, the surface-functionalized GO with RAFT strategy could be successfully employed as a promising nanosensor for selective detecting of Cu (II) ions.

Tailored Design of Au Nanoparticle-siRNA Carriers Utilizing Reversible Addition−Fragmentation Chain Transfer Polymers∥

2010 ◽  
Vol 11 (4) ◽  
pp. 1052-1059 ◽  
Author(s):  
Stacey Kirkland-York ◽  
Yilin Zhang ◽  
Adam E. Smith ◽  
Adam W. York ◽  
Faqing Huang ◽  
...  
Keyword(s):  
Chain Transfer ◽  
Au Nanoparticle ◽  
Reversible Addition ◽  
Tailored Design

Self-Healing Hydrophobic POSS-functionalized Fluorinated Copolymer via RAFT Polymerization and dynamic Diels-Alder Reaction

2021 ◽  
Author(s):  
Siva Ponnupandian ◽  
Prantik Mondal ◽  
Thomas Becker ◽  
Richard Hoogenboom ◽  
Andrew B Lowe ◽  
...  
Keyword(s):  
Chain Transfer ◽  
Raft Polymerization ◽  
Alder Reaction ◽  
Diels Alder ◽  
Self Healing ◽  
Diels Alder Reaction ◽  
Reversible Addition

This investigation reports the preparation of a tailor-made copolymer of furfuryl methacrylate (FMA) and trifluoroethyl methacrylate (TFEMA) via reversible addition-fragmentation chain transfer (RAFT) polymerization. The furfuryl groups of the copolymer...

scholarly journals Synthesis of aminated polystyrene and its self-assembly with nanoparticles at oil/water interface

e-Polymers ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 317-327
Author(s):  
Chenliang Shi ◽  
Ling Lin ◽  
Yukun Yang ◽  
Wenjia Luo ◽  
Maoqing Deng ◽  
...  
Keyword(s):  
Interfacial Tension ◽  
Self Assembly ◽  
Carbon Dots ◽  
Chain Transfer ◽  
Functionalized Polymers ◽  
Amino Groups ◽  
One Dimensional ◽  
Reversible Addition ◽  
Oil Water ◽  
Chain Transfer Polymerization

AbstractThe influence of density of amino groups, nanoparticles dimension and pH on the interaction between end-functionalized polymers and nanoparticles was extensively investigated in this study. PS–NH2 and H2N–PS–NH2 were prepared using reversible addition–fragmentation chain transfer polymerization and atom transfer radical polymerization. Zero-dimensional carbon dots with sulfonate groups, one-dimensional cellulose nanocrystals with sulfate groups and two-dimensional graphene with sulfonate groups in the aqueous phase were added into the toluene phase containing the aminated PS. The results indicate that aminated PS exhibited the strongest interfacial activity after compounding with sulfonated nanoparticles at a pH of 3. PS ended with two amino groups performed better in reducing the water/toluene interfacial tension than PS ended with only one amino group. The dimension of sulfonated nanoparticles also contributed significantly to the reduction in the water/toluene interfacial tension. The minimal interfacial tension was 4.49 mN/m after compounding PS–NH2 with sulfonated zero-dimensional carbon dots.

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