Rheological Behavior of Polystyrene-Based Nanocomposite Suspensions under LAOS

Polymer nanocomposites based on polyhedral oligomeric silsesquioxanes (POSS) and their solutions and suspensions are promising systems for fundamental research which could potentially utilize self-assembly approach in designing new nanocomposite materials. Numerous applications could benefit from understanding of these systems, for instance polymer solution based paints and varnishes. This work is an initial stage of a study which aim is to link macroscale thermomechanical properties with nanoscale structures found in polymer nanocomposites. To do so, a suitable experimental protocol for preparing differently organized NPs in polymer matrix has to be find first in which both kinetic and thermodynamical parameters should be taken into account, i.e. solution casting has being investigated. The results presented here found differences between nanoparticle induced changes on rheological behavior of polystyrene solution under large amplitude oscillation shear (LAOS). High-affinity OP-POSS NPs seem to interact with PS at low loadings and form stiffened aggregates, whereas low-affinity OM-POSS NPs remained rather uninvolved. Effect of hydrodynamic forces independent of the NPs chemical nature was also observed.

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Polymer Nanocomposites Containing Polyhedral Oligomeric Silsesquioxanes (POSS)

10.21236/ada433239 ◽

2004 ◽

Cited By ~ 1

Author(s):

Joseph M. Mabry ◽

Timothy S. Haddad ◽

Steven A. Svejda

Keyword(s):

Polymer Nanocomposites ◽

Polyhedral Oligomeric Silsesquioxanes

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Interfacial Crystallization and Supramolecular Self-Assembly of Spider Silk Inspired Protein at the Water-Air Interface

Materials ◽

10.3390/ma14154239 ◽

2021 ◽

Vol 14 (15) ◽

pp. 4239

Author(s):

Pezhman Mohammadi ◽

Fabian Zemke ◽

Wolfgang Wagermaier ◽

Markus B. Linder

Keyword(s):

Self Assembly ◽

Spider Silk ◽

Assembly Process ◽

Protein Solution ◽

Time Resolved ◽

Macromolecular Assembly ◽

X Ray Scattering ◽

Air Interface ◽

Fundamental Research ◽

Β Sheet

Macromolecular assembly into complex morphologies and architectural shapes is an area of fundamental research and technological innovation. In this work, we investigate the self-assembly process of recombinantly produced protein inspired by spider silk (spidroin). To elucidate the first steps of the assembly process, we examined highly concentrated and viscous pendant droplets of this protein in air. We show how the protein self-assembles and crystallizes at the water–air interface into a relatively thick and highly elastic skin. Using time-resolved in situ synchrotron X-ray scattering measurements during the drying process, we showed that the skin evolved to contain a high β-sheet amount over time. We also found that β-sheet formation strongly depended on protein concentration and relative humidity. These had a strong influence not only on the amount, but also on the ordering of these structures during the β-sheet formation process. We also showed how the skin around pendant droplets can serve as a reservoir for attaining liquid–liquid phase separation and coacervation from the dilute protein solution. Essentially, this study shows a new assembly route which could be optimized for the synthesis of new materials from a dilute protein solution and determine the properties of the final products.

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Self-assembly and rheological behavior of chloramphenicol-based poly(ester ether)urethanes

Journal of Polymer Research ◽

10.1007/s10965-021-02545-7 ◽

2021 ◽

Vol 28 (5) ◽

Author(s):

Mirela-Fernanda Zaltariov ◽

Daniela Filip ◽

Doina Macocinschi ◽

Constanta Ibanescu ◽

Maricel Danu ◽

...

Keyword(s):

Rheological Behavior ◽

Self Assembly

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Quadruple Hydrogen Bond-Containing A-AB-A Triblock Copolymers: Probing the Influence of Hydrogen Bonding in the Central Block

Molecules ◽

10.3390/molecules26154705 ◽

2021 ◽

Vol 26 (15) ◽

pp. 4705

Author(s):

Boer Liu ◽

Xi Chen ◽

Glenn A. Spiering ◽

Robert B. Moore ◽

Timothy E. Long

Keyword(s):

Hydrogen Bonding ◽

Self Assembly ◽

Microphase Separation ◽

Triblock Copolymers ◽

Random Copolymer ◽

Thermomechanical Properties ◽

Structure Property ◽

Scanning Calorimetry ◽

Central Block ◽

Quadruple Hydrogen Bonding

This work reveals the influence of pendant hydrogen bonding strength and distribution on self-assembly and the resulting thermomechanical properties of A-AB-A triblock copolymers. Reversible addition-fragmentation chain transfer polymerization afforded a library of A-AB-A acrylic triblock copolymers, wherein the A unit contained cytosine acrylate (CyA) or post-functionalized ureido cytosine acrylate (UCyA) and the B unit consisted of n-butyl acrylate (nBA). Differential scanning calorimetry revealed two glass transition temperatures, suggesting microphase-separation in the A-AB-A triblock copolymers. Thermomechanical and morphological analysis revealed the effects of hydrogen bonding distribution and strength on the self-assembly and microphase-separated morphology. Dynamic mechanical analysis showed multiple tan delta (δ) transitions that correlated to chain relaxation and hydrogen bonding dissociation, further confirming the microphase-separated structure. In addition, UCyA triblock copolymers possessed an extended modulus plateau versus temperature compared to the CyA analogs due to the stronger association of quadruple hydrogen bonding. CyA triblock copolymers exhibited a cylindrical microphase-separated morphology according to small-angle X-ray scattering. In contrast, UCyA triblock copolymers lacked long-range ordering due to hydrogen bonding induced phase mixing. The incorporation of UCyA into the soft central block resulted in improved tensile strength, extensibility, and toughness compared to the AB random copolymer and A-B-A triblock copolymer comparisons. This study provides insight into the structure-property relationships of A-AB-A supramolecular triblock copolymers that result from tunable association strengths.

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Influence of octakis-functionalized polyhedral oligomeric silsesquioxanes on the physical properties of their polymer nanocomposites

Polymer ◽

10.1016/j.polymer.2009.08.026 ◽

2009 ◽

Vol 50 (20) ◽

pp. 4876-4887 ◽

Cited By ~ 54

Author(s):

Kai-Wei Huang ◽

Li-Wei Tsai ◽

Shiao-Wei Kuo

Keyword(s):

Physical Properties ◽

Polymer Nanocomposites ◽

Polyhedral Oligomeric Silsesquioxanes

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Thermomechanical Properties of Poly(methyl methacrylate)s Containing Tethered and Untethered Polyhedral Oligomeric Silsesquioxanes

Macromolecules ◽

10.1021/ma802327e ◽

2008 ◽

Vol 41 (22) ◽

pp. 8951-8951 ◽

Cited By ~ 2

Author(s):

Edward T. Kopesky ◽

Timothy S. Haddad ◽

Robert E. Cohen ◽

Gareth H. McKinley

Keyword(s):

Methyl Methacrylate ◽

Thermomechanical Properties ◽

Polyhedral Oligomeric Silsesquioxanes ◽

Poly Methyl Methacrylate

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Precrystalline P3HT nanowires: growth-controllable solution processing and effective molecular packing transfer to thin-film

CrystEngComm ◽

10.1039/d1ce01536b ◽

2022 ◽

Author(s):

Seon-Mi Jin ◽

Jun Ho Hwang ◽

Jung Ah Lim ◽

Eunji Lee

Keyword(s):

Thin Film ◽

Conjugated Polymers ◽

Self Assembly ◽

Optoelectronic Devices ◽

Molecular Packing ◽

Solution Processing ◽

Roll To Roll ◽

Nanowires Growth ◽

Fundamental Research ◽

Significant Attention

Solution-processable precrystalline nanowires (NWs) of conjugated polymers (CPs) have garnered significant attention in fundamental research based on crystallization-driven self-assembly and in the roll-to-roll fabrication of optoelectronic devices such as organic...

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Direct, single-step synthesis of hierarchical zeolites without secondary templating

Journal of Materials Chemistry A ◽

10.1039/c4ta05031b ◽

2015 ◽

Vol 3 (3) ◽

pp. 1298-1305 ◽

Cited By ~ 43

Author(s):

Zhuopeng Wang ◽

Chao Li ◽

Hong Je Cho ◽

Shih-Chieh Kung ◽

Mark A. Snyder ◽

...

Keyword(s):

Catalytic Activity ◽

Mass Transport ◽

Self Assembly ◽

Single Step ◽

Hierarchical Zeolites ◽

Hierarchical Zeolite ◽

Initial Stage ◽

Zeolite Precursors

Hierarchical ZSM-5 with a shell of stacked coffin-shaped crystals and a core of nanocrystal aggregates was synthesized by controlling the formation and self-assembly of zeolite precursors formed in the initial stage of crystallization. The formed hierarchical zeolite shows superior catalytic activity for reaction involving bulky molecules due to enhanced mass transport.

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