Synthesis of Aminated Polystyrene and Its Self-assembly with Nanoparticles at Oil/water Interface

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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Manuscript-C-dots assembly at interface-041020.pdf

10.26434/chemrxiv.12114063 ◽

2020 ◽

Author(s):

Amin Reza Zolghadr ◽

Behnam Rostami

Keyword(s):

Self Assembly ◽

Carbon Dots ◽

Sodium Dodecyl ◽

Surface Region ◽

Systematic Investigation ◽

Dynamics Simulation ◽

Surface Tension Gradient ◽

Bivariate Analysis ◽

Air Interface ◽

Sds Surfactant

We describe a systematic investigation of carbon dots (C-dots) assemblies fabricated at the liquid/air interface because of the surface tension gradient. This gradient is originally created by capillary action and increased by addition of sodium dodecyl sulfate (SDS) surfactant or 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) phospholipid to the surface of C-dots aqueous mixture. The arrangement of carbon dots in liquid bulk phase (before self-assembly) and at the surface region (after self-assembly) was examined by TEM microscopy. The presence of SDS surfactant and POPC phospholipid at the air/water interface induced the C-dots compression. In addition, molecular dynamics simulation was conducted to obtain the structure of C-dots at liquid/vapor interface. The orientation of C-dots is evaluated quantitatively at water/vapor surface by using bivariate analysis.

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Unravelling a Novel Sol-Gel Transition Mechanism in Polymer Self-Assemblies: An Order-Order Transition Based on Specific Molecular Interactions Between Hydrophilic and Hydrophobic Polymer Blocks

10.26434/chemrxiv.14362892 ◽

2021 ◽

Author(s):

Lukas Hahn ◽

Theresa Zorn ◽

Josef Kehrrein ◽

Tobias Kielholz ◽

Benedikt Sochor ◽

...

Keyword(s):

Self Assembly ◽

Sol Gel ◽

Analytical Techniques ◽

Order Transition ◽

Dynamics Simulation ◽

Aqueous Polymer ◽

Transition Mechanism ◽

Wide Range ◽

Spherical Micelles ◽

Sol Gel Transition

Using a wide range of state-of-the art analytical techniques and molecular dynamics simulation, a novel mechanism for macromolecular interactions are described. Distinct interactions between the hydrophilic and hydrophobic blocks in amphiphilic triblock copolymers lead to an order-order transition from spherical micelles to worm-like micelles upon cooling the aqueous polymer solutions below room temperature. Macroscopically, this this leads to reversible gelation. This novel mechanism represent a novel building block to better understand polymer self-assembly.

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Luminescent Water Dispersible Microporous Polymeric Nanospheres

10.26434/chemrxiv.7314779 ◽

2018 ◽

Author(s):

Alex James ◽

Matthew Derry ◽

Jennifer Train ◽

Robert Dawson

Keyword(s):

Self Assembly ◽

Picric Acid ◽

Water Dispersible ◽

X Ray Scattering ◽

Reversible Addition ◽

Wide Range ◽

Small Primary ◽

Shell Particles ◽

Polymeric Nanospheres ◽

Polymeric Dispersions

Water-dispersible porous polymeric dispersions (PPDs) have been synthesised by reversible addition-fragmentation chain transfer mediated polymerisation-induced self-assembly (RAFT-mediated PISA). The core-shell particles posses a microporous core formed from divinylbenzene and fumaronitrile while the outer polyethylene glycol shell enables the particles to be dispersible in a wide range of solvents. The PPD was shown to have a heirarchical structure of small primary nanoparticles within larger, well-defined aggregates of 220 nm as measured by electron microscopy and small angle x-ray scattering (SAXS) and exhibited a surface area of 274 m2/g. Furthermore these samples were found to be fluoresent and demonstrate selective detection of harmful nitroaramatics in solution with extremly low limits of detection, 169 ppb for picric acid, as well as possessing a CO2 uptake of 1.1 mmol/g at 273 K.

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Manuscript-C-dots assembly at interface-041020.pdf

10.26434/chemrxiv.12114063.v1 ◽

2020 ◽

Author(s):

Amin Reza Zolghadr ◽

Behnam Rostami

Keyword(s):

Self Assembly ◽

Carbon Dots ◽

Sodium Dodecyl ◽

Surface Region ◽

Systematic Investigation ◽

Dynamics Simulation ◽

Surface Tension Gradient ◽

Bivariate Analysis ◽

Air Interface ◽

Sds Surfactant

We describe a systematic investigation of carbon dots (C-dots) assemblies fabricated at the liquid/air interface because of the surface tension gradient. This gradient is originally created by capillary action and increased by addition of sodium dodecyl sulfate (SDS) surfactant or 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) phospholipid to the surface of C-dots aqueous mixture. The arrangement of carbon dots in liquid bulk phase (before self-assembly) and at the surface region (after self-assembly) was examined by TEM microscopy. The presence of SDS surfactant and POPC phospholipid at the air/water interface induced the C-dots compression. In addition, molecular dynamics simulation was conducted to obtain the structure of C-dots at liquid/vapor interface. The orientation of C-dots is evaluated quantitatively at water/vapor surface by using bivariate analysis.

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RAFT Chemistry and Huisgen 1,3-Dipolar Cycloaddition: A Route to Block Copolymers of Vinyl Acetate and 6-O-Methacryloyl Mannose?

Australian Journal of Chemistry ◽

10.1071/ch07089 ◽

2007 ◽

Vol 60 (6) ◽

pp. 405 ◽

Cited By ~ 54

Author(s):

S. R. Simon Ting ◽

Anthony M. Granville ◽

Damien Quémener ◽

Thomas P. Davis ◽

Martina H. Stenzel ◽

...

Keyword(s):

Block Copolymers ◽

Vinyl Acetate ◽

Self Assembly ◽

Average Molecular Weight ◽

Dipolar Cycloaddition ◽

Hydrodynamic Diameter ◽

Transmission Electron ◽

Reversible Addition ◽

Polymer Distribution ◽

Two Phases

The present communication explores a novel avenue to glycopolymer-block-poly(vinyl acetate) polymers by a combination of reversible addition fragmentation chain transfer (RAFT) chemistry and Huisgen 1,3-dipolar cycloaddition (i.e., so-called ‘click’ chemistry) under mild reaction conditions. Such block copolymers are—because of the strongly disparate reactivity of the two monomers—otherwise not obtainable. Poly(vinyl acetate) that has an azide end group (Mn 6800 g mol–1, PDI 1.15) was treated with poly(6-O-methacryloyl mannose) (Mn 7600 g mol–1, PDI 1.11) in the presence of 1,8-diaza[5,4,0]bicycloundec-7-ene and copper(i) iodide. The resulting poly(vinyl acetate)-block-poly(6-O-methacryloyl mannose) had a number-average molecular weight of 15400 g mol–1 and a PDI of 1.48, which indicates that while the cycloaddition had occurred the resulting polymer distribution featured a considerable width. The resulting slightly amphiphilic block copolymer was subsequently investigated with regard to its self-assembly in aqueous solution. Dynamic light scattering studies indicated a hydrodynamic diameter of close to 200 nm. Transmission electron microscopy studies indicate the formation of rods as well as spheres with transitions between these two phases. However, the segregation between core and shell in the spheres is not pronounced; such behaviour is expected for weakly amphiphilic block copolymers.

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Unravelling a Novel Sol-Gel Transition Mechanism in Polymer Self-Assemblies: An Order-Order Transition Based on Specific Molecular Interactions Between Hydrophilic and Hydrophobic Polymer Blocks

10.26434/chemrxiv.14362892.v1 ◽

2021 ◽

Author(s):

Lukas Hahn ◽

Theresa Zorn ◽

Josef Kehrrein ◽

Tobias Kielholz ◽

Benedikt Sochor ◽

...

Keyword(s):

Self Assembly ◽

Sol Gel ◽

Analytical Techniques ◽

Order Transition ◽

Dynamics Simulation ◽

Aqueous Polymer ◽

Transition Mechanism ◽

Wide Range ◽

Spherical Micelles ◽

Sol Gel Transition

Using a wide range of state-of-the art analytical techniques and molecular dynamics simulation, a novel mechanism for macromolecular interactions are described. Distinct interactions between the hydrophilic and hydrophobic blocks in amphiphilic triblock copolymers lead to an order-order transition from spherical micelles to worm-like micelles upon cooling the aqueous polymer solutions below room temperature. Macroscopically, this this leads to reversible gelation. This novel mechanism represent a novel building block to better understand polymer self-assembly.

Download Full-text

Luminescent Water Dispersible Microporous Polymeric Nanospheres

10.26434/chemrxiv.7314779.v1 ◽

2018 ◽

Author(s):

Alex James ◽

Matthew Derry ◽

Jennifer Train ◽

Robert Dawson

Keyword(s):

Self Assembly ◽

Picric Acid ◽

Water Dispersible ◽

X Ray Scattering ◽

Reversible Addition ◽

Wide Range ◽

Small Primary ◽

Shell Particles ◽

Polymeric Nanospheres ◽

Polymeric Dispersions

Water-dispersible porous polymeric dispersions (PPDs) have been synthesised by reversible addition-fragmentation chain transfer mediated polymerisation-induced self-assembly (RAFT-mediated PISA). The core-shell particles posses a microporous core formed from divinylbenzene and fumaronitrile while the outer polyethylene glycol shell enables the particles to be dispersible in a wide range of solvents. The PPD was shown to have a heirarchical structure of small primary nanoparticles within larger, well-defined aggregates of 220 nm as measured by electron microscopy and small angle x-ray scattering (SAXS) and exhibited a surface area of 274 m2/g. Furthermore these samples were found to be fluoresent and demonstrate selective detection of harmful nitroaramatics in solution with extremly low limits of detection, 169 ppb for picric acid, as well as possessing a CO2 uptake of 1.1 mmol/g at 273 K.

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Factors Affecting Molecular Self-Assembly and Its Mechanism

Scientific Research Journal ◽

10.24191/srj.v9i1.5385 ◽

2012 ◽

Vol 9 (1) ◽

pp. 43 ◽

Cited By ~ 1

Author(s):

Hueyling Tan

Keyword(s):

Self Assembly ◽

Building Blocks ◽

Molecular Engineering ◽

Molecular Structures ◽

Polymer Science ◽

New Approach ◽

Factors Affecting ◽

Dna Structures ◽

Self Assembling ◽

Wide Range

Molecular self-assembly is ubiquitous in nature and has emerged as a new approach to produce new materials in chemistry, engineering, nanotechnology, polymer science and materials. Molecular self-assembly has been attracting increasing interest from the scientific community in recent years due to its importance in understanding biology and a variety of diseases at the molecular level. In the last few years, considerable advances have been made in the use ofpeptides as building blocks to produce biological materials for wide range of applications, including fabricating novel supra-molecular structures and scaffolding for tissue repair. The study ofbiological self-assembly systems represents a significant advancement in molecular engineering and is a rapidly growing scientific and engineering field that crosses the boundaries ofexisting disciplines. Many self-assembling systems are rangefrom bi- andtri-block copolymers to DNA structures as well as simple and complex proteins andpeptides. The ultimate goal is to harness molecular self-assembly such that design andcontrol ofbottom-up processes is achieved thereby enabling exploitation of structures developed at the meso- and macro-scopic scale for the purposes oflife and non-life science applications. Such aspirations can be achievedthrough understanding thefundamental principles behind the selforganisation and self-synthesis processes exhibited by biological systems.

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