Grafting of ‘dendrimer-like’ highly branched polymer onto ultrafine silica surface

Tsubokawa, Norio; Ichioka, Hajime; Satoh, Toshiya; Hayashi, Shinji; Fujiki, Kazuhiro

doi:10.1016/s1381-5148(97)00139-9

Cited by 156 publications

(97 citation statements)

References 11 publications

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“…Figure 4 shows FT-IR spectra of PAMAM-grafted silica nanoparticles obtained using a solvent-free dry-system and from a methanol solvent system. 30 The intensity of the ester bond absorption in the nanoparticles obtained from the solvent-free system is weaker than that of the nanoparticles obtained from the methanol solvent system. This indicates that amidation of the terminal methyl ester groups was more effective in the solvent-free dry-system.…”

Section: Grafting Of Hyperbranched Poly(amidoamine) Onto Silica Nanopmentioning

confidence: 90%

“…The same tendency was observed for grafting of PAMAM onto silica nanoparticles in a methanol solvent system. [30][31][32][33] Figure 3(B) and (C) also show FT-IR spectra of PAMAM-grafted silica nanoparticles with repeated reaction cycles of 3-times and 6-times. The absorption at 1655 cm À1 , characteristic of amide group, increased with repeated reaction cycles.…”

Section: Grafting Of Hyperbranched Poly(amidoamine) Onto Silica Nanopmentioning

confidence: 99%

“…28,29 We reported that hyperbranched poly(amidoamine) (PAMAM) can be grown from amino groups on the surface of nanoparticles such as silica, 30,31 carbon black, 32 and chitosan powder 33 using dendrimer synthesis methodology in a methanol solvent.…”

Section: Grafting Of Hyperbranched Poly(amidoamine) Onto Silica Nanopmentioning

confidence: 99%

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Surface Grafting of Polymers onto Nanoparticles in a Solvent-Free Dry-System and Applications of Polymer-grafted Nanoparticles as Novel Functional Hybrid Materials

Tsubokawa

2007

Polym J

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ABSTRACT:For the prevention of environmental pollution and simplification of reactions, scale-up synthesis of polymer-grafted inorganic nanoparticles in a solvent-free dry-system is reviewed. The grafting of polymers onto nanoparticles in a solvent-free dry-system was achieved by spraying monomers onto nanoparticles having initiating group. After the reaction, unreacted monomer and by-products were removed under high vacuum. For example, grafting of hyperbranched poly(amidoamine) (PAMAM) was successfully achieved using dendrimer synthesis methodology in a solvent-free dry-system. The percentage of PAMAM grafting onto the nanoparticle surface was 141% with repeated reaction cycles of 8-times. In addition, radical graft polymerization of vinyl monomers onto silica nanoparticles was achieved by spraying the monomers onto silica nanoparticles containing azo and peroxycarbonate groups in a solvent-free dry-system. The formation of ungrafted polymer was depressed in comparison with graft polymerization in solution: the grafting efficiency was 90-95%. PAMAM-grafted silica dispersed uniformly in epoxy resin and has an ability to cure the epoxy resin. Glass transition temperature of cured material was much higher than that of the material cured by conventional curing agents. The immobilization of norbornadiene, capsaicin, and flame retardant onto PAMAM-grafted nanoparticle and the properties of the resulting materials are also described.

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Section: Grafting Of Hyperbranched Poly(amidoamine) Onto Silica Nanopmentioning

confidence: 90%

Section: Grafting Of Hyperbranched Poly(amidoamine) Onto Silica Nanopmentioning

confidence: 99%

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Surface Grafting of Polymers onto Nanoparticles in a Solvent-Free Dry-System and Applications of Polymer-grafted Nanoparticles as Novel Functional Hybrid Materials

Tsubokawa

2007

Polym J

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“…20,21 Surface functionalization could also be performed by condensation reactions. [22][23][24][25] Polyimides have shown outstanding thermal and electrical properties and wide applications in microelectronic, energy, and aerospace industry. [26][27][28][29][30] Polyimide-surface-functionalized mesoporous silica 24 and silica tubes 25 were obtained for the preparation of polyimide-silica nanocomposites.…”

Section: Introductionmentioning

confidence: 99%

Surface grafting of polyimide onto silicon surface: Preparation and characterization

Liu¹,

Chen²,

Liu³

2007

J. Polym. Sci. A Polym. Chem.

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“…For example the propagation of PAMAM (polyamidoamine) dendrons on silica can be accomplished by a series of alternate Michael addition and amidation reactions [14]. PAMAM modified silica is further functionalized with long aliphatic chains to the periphery of the dendron for applications in pollutant encapsulation.…”

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confidence: 99%

Hybrid Organic/Inorganic Materials Based on Functionalized Dendritic Polymers: Methods of Preparation, Applications and Future Prospects

Arkas¹

2012

J Material Sci Eng

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Dendritic polymers [1][2][3][4][5][6] is a special class of macromolecules consisting of monomeric units branching out from a common centre. The name dendritic is derived from the Greek word "Dendritic" meaning "tree-like". They consist of four subcategories which correspond to different topologies: i) dendrimers: perfectly symmetric macromolecules with precisely fixed number of monomeric units ii) hyperbranched polymers: non-symmetrical, polydisperse, randomly polymerized macromolecules iii) dendrons: monodisperse wedge-shaped dendrimer sections iv) dendrigrafts: dendritic structures that are grown on reactive linear polymers or oligomersThe distinctive highly branched chemical structure of dendritic polymers has nanosized dimensions and consists of the central core, the repeating units and the terminal functional groups. Due to these structural features, they possess nanocavities that are able to encapsulate various molecules, while their external surfaces can be easily functionalized. In addition, their terminal groups can exhibit the so-called polyvalency effect [7,8], which enhances their binding with other substrates.The diversity of dendritic polymers nanocavities as far as the size, polarity and interaction ability are concerned, provides the basis for the formation of devices bearing nanosized containers for effectively encapsulating metal ions. Thus, colloidal silver nanoparticles are obtained by the reduction Ag+ ions encapsulated into Polyethylene Imine (PEI) Hyperbranched Polymer even in the absence of another reductant [9]. Dendritic polymers also stabilize colloidal suspensions of gold by in situ reduction of HAuCl 4 encapsulated into Polyamidoamine PAMAM Dendrimers by aqueous NaBH 4 solution [10]. These dendritic polymer/noble metal composites have unique potential for applications such as catalysis.On the other hand the terminal functional groups can be involved in a variety of interactions/modifications. For example the amines of the poly (propyleneimine) and poly (amidoamine) dendrimers and hyperbranched polymers act as templates for biomimetic silica nanospheres formation [11]. The sol-gel reactions proceed at room temperature by the addition of metastable silicic acid into the dendrimer solution in phosphate buffer, pH 7.5. The dendritic polymers, although incorporated in the nanospheres, retain their property of encapsulating metal ions and therefore, can be applied for catalysis. In addition a variety of other compounds can be encapsulated depending on the microenvironment of the nanocavities, which is primarily affected by the structural characteristics of the repeating units. In this manner, encapsulation of impurities dissolved in water leads, using appropriate methods, to novel bulk water purification technologies [12] and the solubilisation of bioactive compounds in their interior could lead to the development of effective drug and gene delivery systems [13].The reactivity of the functionalized terminal groups of the dendritic polymers can result in chemical bond formation with differ...

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Grafting of ‘dendrimer-like’ highly branched polymer onto ultrafine silica surface

Cited by 156 publications

References 11 publications

Surface Grafting of Polymers onto Nanoparticles in a Solvent-Free Dry-System and Applications of Polymer-grafted Nanoparticles as Novel Functional Hybrid Materials

Surface Grafting of Polymers onto Nanoparticles in a Solvent-Free Dry-System and Applications of Polymer-grafted Nanoparticles as Novel Functional Hybrid Materials

Surface grafting of polyimide onto silicon surface: Preparation and characterization

Hybrid Organic/Inorganic Materials Based on Functionalized Dendritic Polymers: Methods of Preparation, Applications and Future Prospects

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