Synthesis of CO2-responsive gradient copolymers by switchable RAFT polymerization and their controlled self-assembly

2020 ◽  
Vol 11 (42) ◽  
pp. 6794-6802
Author(s):  
Xiaofeng Guo ◽  
Tianren Zhang ◽  
Yuetong Wu ◽  
Wencheng Shi ◽  
Bonnie Choi ◽  
...  
Keyword(s):  
Self Assembly ◽  
Raft Polymerization ◽  
Good Control ◽  
Acid Base ◽  
Gradient Copolymers

Switchable RAFT agents, so-called because they can be reversibly switched by an acid/base stimulus to offer very good control over polymerization of both MAMs and LAMs, provide a route to prepare well-defined polyMAM-block-polyLAM copolymers.

Synthesis of microcapsules using inverse emulsion periphery RAFT polymerization via SPG membrane emulsification

2016 ◽  
Vol 7 (46) ◽  
pp. 7047-7051 ◽  
Author(s):  
Fumi Ishizuka ◽  
Rhiannon P. Kuchel ◽  
Hongxu Lu ◽  
Martina H. Stenzel ◽  
Per B. Zetterlund
Keyword(s):  
Particle Size ◽  
Size Distribution ◽  
Raft Polymerization ◽  
Good Control ◽  
Membrane Emulsification ◽  
Inverse Emulsion ◽  
Novel Approach ◽  
Spg Membrane Emulsification

Synthesis of polymeric capsules with good control over the particle size and size distribution is demonstratedviaa novel approach involving SPG membrane emulsification.

Engineering the shape of Zinc Oxide crystals via sonochemical or hydrothermal solution-based methods

2008 ◽  
Vol 1087 ◽  
Author(s):  
Marco Palumbo ◽  
Simon J. Henley ◽  
Thierry Lutz ◽  
Vlad Stolojan ◽  
David Cox ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Self Assembly ◽  
Hydrothermal Solution ◽  
Good Control ◽  
Transparent Conductors ◽  
Zno Nanostructures ◽  
Large Area ◽  
Light Emitting Devices ◽  
Wide Range ◽  
Solution Methods

AbstractRecent results in the use of Zinc Oxide (ZnO) nano/submicron crystals in fields as diverse as sensors, UV lasers, solar cells, piezoelectric nanogenerators and light emitting devices have reinvigorated the interest of the scientific community in this material. To fully exploit the wide range of properties offered by ZnO, a good understanding of the crystal growth mechanism and related defects chemistry is necessary. However, a full picture of the interrelation between defects, processing and properties has not yet been completed, especially for the ZnO nanostructures that are now being synthesized. Furthermore, achieving good control in the shape of the crystal is also a very desirable feature based on the strong correlation there is between shape and properties in nanoscale materials. In this paper, the synthesis of ZnO nanostructures via two alternative aqueous solution methods - sonochemical and hydrothermal - will be presented, together with the influence that the addition of citric anions or variations in the concentration of the initial reactants have on the ZnO crystals shape. Foreseen applications might be in the field of sensors, transparent conductors and large area electronics possibly via ink-jet printing techniques or self-assembly methods.

A ‘Building Block’ Approach To Mixed-Colloid Systems Through Electrostatic Self-Organization

2001 ◽  
Vol 676 ◽  
Author(s):  
Trent H. Galow ◽  
Andrew K. Boal ◽  
Vincent M. Rotello
Keyword(s):  
Particle Size ◽  
Self Assembly ◽  
Building Block ◽  
Acid Base ◽  
Electrostatic Assembly ◽  
Polymer Colloid ◽  
Colloid Systems ◽  
Carboxylic Acid Derivative ◽  
Block Approach ◽  
Shape And Size

ABSTRACTWe have developed a highly modular electrostatically-mediated approach to colloid-colloid and polymer-colloid networks using ‘building block’ and ‘bricks and mortar’ self-assembly methodologies, respectively. The former approach involved functionalization of one type of nanoparticle building block with a primary amine and a counterpart building block with a carboxylic acid derivative. After combining these two systems, acid-base chemistry followed by immediate charge-pairing resulted in the spontaneous formation of electrostatically-bound mixed-nanoparticle constructs. The shape and size of these ensembles were controlled via variation of particle size and stoichiometries. In the ‘bricks and mortar’ approach, a functionalized polymer is combined with complementary nanoparticles to provide mixed polymer-nanoparticle networked structures. A notable feature is the inherent porosity resulting from the electrostatic assembly. The shape and size of these ensembles were controlled via variation of particle size, stoichiometries and the order in which they were added.

scholarly journals Nanostructure-directed chemical sensing: The IHSAB principle and the dynamics of acid/base-interface interaction

2013 ◽  
Vol 4 ◽  
pp. 20-31 ◽  
Author(s):  
James L Gole ◽  
William Laminack
Keyword(s):  
Metal Oxide ◽  
Self Assembly ◽  
Chemical Sensing ◽  
Optical Pumping ◽  
Relative Strength ◽  
Acid Base ◽  
Semiconductor Interfaces ◽  
Surface Basicity ◽  
Metal Oxide Sensors ◽  
Type Semiconductor

Nanostructure-decorated n-type semiconductor interfaces are studied in order to develop chemical sensing with nanostructured materials. We couple the tenets of acid/base chemistry with the majority charge carriers of an extrinsic semiconductor. Nanostructured islands are deposited in a process that does not require self-assembly in order to direct a dominant electron-transduction process that forms the basis for reversible chemical sensing in the absence of chemical-bond formation. Gaseous analyte interactions on a metal-oxide-decorated n-type porous silicon interface show a dynamic electron transduction to and from the interface depending upon the relative strength of the gas and metal oxides. The dynamic interaction of NO with TiO2, SnO2, NiO, Cu x O, and Au x O (x >> 1), in order of decreasing acidity, demonstrates this effect. Interactions with the metal-oxide-decorated interface can be modified by the in situ nitridation of the oxide nanoparticles, enhancing the basicity of the decorated interface. This process changes the interaction of the interface with the analyte. The observed change to the more basic oxinitrides does not represent a simple increase in surface basicity but appears to involve a change in molecular electronic structure, which is well explained by using the recently developed IHSAB model. The optical pumping of a TiO2 and TiO2− x N x decorated interface demonstrates a significant enhancement in the ability to sense NH3 and NO2. Comparisons to traditional metal-oxide sensors are also discussed.

scholarly journals Geometry-Wave Potential Quantified and Unified Properties in General Chemistry

2020 ◽  
Author(s):  
Zheng Tian
Keyword(s):  
General Chemistry ◽  
Surface Chemistry ◽  
Lewis Acid ◽  
Self Assembly ◽  
Redox Chemistry ◽  
Acid Base ◽  
Wave Potential ◽  
First Time

Many long-known but never-quantified properties in chapters of general chemistry have for the first time been quantitatively compared and consistently unified, using the newly introduced geometro-wave (GW) potential of particles (i.e. atoms, molecules, clusters, ions, and nanoparticles). Th GW Potential has helped update the electrochemistry, Lewis acid-base chemistry, redox chemistry, self-assembly, surface chemistry, catalysis, and inter-nanoparticle bonding.

scholarly journals Crystal engineered acid-base complexes with 2d and 3d hydrogen bonding systems using p-hydroxybenzoic acid as the building block

2010 ◽  
Vol 75 (4) ◽  
pp. 459-473 ◽  
Author(s):  
Pu Zhao ◽  
Xian Wang ◽  
Fang Jian ◽  
Jun Zhang ◽  
Lian Xiao
Keyword(s):  
Self Assembly ◽  
Building Block ◽  
Three Dimensional ◽  
Hydroxybenzoic Acid ◽  
Acid Base ◽  
3D Network ◽  
Acid And Base ◽  
Butyl Amine ◽  
Bonding Systems ◽  
Simply Connected

p-Hydroxybenzoic acid (p-HOBA) was selected as the building block for self-assembly with five bases, i.e., diethylamine, tert-butyl amine, cyclohexylamine, imidazole and piperazine, and generate the corresponding acid-base complexes 1-5. Crystal structure analyses suggest that proton-transfer from the carboxyl hydrogen to the nitrogen atom of the bases can be observed in 1-4; while only in 5 does a solvent water molecule co-exists with p-HOBA and piperazine. With the presence of O-H?O hydrogen bonds in 1-4, the deprotonated p-hydroxybenzoate anions (p-HOBAA-) are simply connected each other in a head-to-tail motif to form one-dimensional (1D) arrays, which are further extended to distinct two-dimensional (2D) (for 1 and 4) and three-dimensional (3D) (for 2 and 3 ) networks via N-H?O interactions. While in 5, neutral acid and base are combined pair wise by O-H?N and N-H?O bonds to form a 1D tape and then the 1D tapes are sequentially combined by water molecules to create a 3D network. Some interlayer or intralayer C-H?O, C-H?? and ??? interactions help to stabilize the supramolecular buildings. Melting point determination analyses indicate that the five acidbase complexes are not the ordinary superposition of the reactants and they are more stable than the original reactants.

Oxidation-responsive micelles by a one-pot polymerization-induced self-assembly approach

2018 ◽  
Vol 9 (13) ◽  
pp. 1593-1602 ◽  
Author(s):  
Fabian H. Sobotta ◽  
Franziska Hausig ◽  
Dominic O. Harz ◽  
Stephanie Hoeppener ◽  
Ulrich S. Schubert ◽  
...  
Keyword(s):  
Self Assembly ◽  
Raft Polymerization ◽  
Assembly Process ◽  
Carrier System ◽  
One Pot ◽  
System P

Combining a sequential, one-pot RAFT polymerization with the polymerization-induced self-assembly process results in a versatile oxidation-responsive carrier system.

scholarly journals Self-Assembly of Hydrogen-Bonding Gradient Copolymers: Sequence Control via Tandem Living Radical Polymerization with Transesterification

2017 ◽  
Vol 50 (8) ◽  
pp. 3215-3223 ◽  
Author(s):  
Yusuke Ogura ◽  
Müge Artar ◽  
Anja R. A. Palmans ◽  
Mitsuo Sawamoto ◽  
E. W. Meijer ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Radical Polymerization ◽  
Self Assembly ◽  
Living Radical Polymerization ◽  
Gradient Copolymers

Control of Self-Assembly by Acid-Base Chemistry

1995 ◽  
pp. 195-197
Author(s):  
R. M. Grotzfeld ◽  
N. R. Branda ◽  
C. Valdes ◽  
J. Rebek
Keyword(s):  
Self Assembly ◽  
Acid Base

Solvent Effects on the Synthesis of Polymeric Nanoparticles via Block Copolymer Self-Assembly Using Microporous Membranes

2020 ◽  
Vol 1000 ◽  
pp. 324-330
Author(s):  
Sri Agustina ◽  
Masayoshi Tokuda ◽  
Hideto Minami ◽  
Cyrille Boyer ◽  
Per B. Zetterlund
Keyword(s):  
Block Copolymer ◽  
Block Copolymers ◽  
Self Assembly ◽  
Polymeric Nanoparticles ◽  
Raft Polymerization ◽  
Membrane Emulsification ◽  
Membrane Pore ◽  
Novel Technique ◽  
Wide Range ◽  
Membrane Pore Size

The self-assembly of block copolymers has attracted attention for many decades because it can yield polymeric nanoobjects with a wide range of morphologies. Membrane emulsification is a fairly novel technique for preparation of various types of emulsions, which relies on the dispersed phase passing through a membrane in order to effect droplet formation. In this study, we have prepared polymeric nanoparticles of different morphologies using self-assembly of asymmetric block copolymers in connection with membrane emulsification. Shirasu Porous Glass (SPG) membranes has been employed as the membrane emulsification equipment, and poly (oligoethylene glycol acrylate)-block-poly (styrene) (POEGA-b-PSt) copolymers prepared via RAFT polymerization. It has been found that a number of different morphologies can be achieved using this novel technique, including spheres, rods, and vesicles. Interestingly, the results have shown that the morphology can be controlled not only by adjusting experimental parameters specific to the membrane emulsification step such as membrane pore size and pressure, but also by changing the nature of organic solvent. As such, this method provides a novel route to these interesting nanoobjects, with interesting prospects in terms of exercising morphology control without altering the nature of the block copolymer itself.

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