Impact of Cyclic Block Copolymer Chain Architecture and Degree of Polymerization on Nanoscale Domain Spacing: A Simulation and Scaling Theory Analysis

Asymmetrical vesicles of a block copolymer were prepared, and the vesicle structure was found to be dependent on the degree of polymerization of solvophilic blocks.

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Ethanolic RAFT Dispersion Polymerization of 2-(Naphthalen-2-yloxy)ethyl Methacrylate and 2-Phenoxyethyl Methacrylate with Poly[2-(dimethylamino)ethyl Methacrylate] Macro-Chain Transfer Agents

Australian Journal of Chemistry ◽

10.1071/ch14490 ◽

2015 ◽

Vol 68 (6) ◽

pp. 939 ◽

Cited By ~ 15

Author(s):

Yiwen Pei ◽

Nadia C. Dharsana ◽

Andrew B. Lowe

Keyword(s):

Block Copolymer ◽

Block Copolymers ◽

Dispersion Polymerization ◽

Chain Transfer ◽

Narrow Range ◽

Degree Of Polymerization ◽

Size Exclusion ◽

Full Spectrum ◽

Ethyl Methacrylate ◽

Reversible Addition

The ethanolic reversible addition-fragmentation chain transfer dispersion polymerization (RAFTDP), at 21 wt-%, of 2-(naphthalen-2-yloxy)ethyl methacrylate (NOEMA) and 2-phenoxyethyl methacrylate (POEMA) with a poly[2-(dimethylamino)ethyl methacrylate] macro-chain transfer agent (CTA) with an average degree of polymerization of 20 (PDMAEMA20) is described. DMAEMA20-b-NOEMAy (y = 20–125) block copolymers were readily prepared under dispersion conditions in ethanol at 70°C. However, the polymerization of NOEMA was not well controlled, with size exclusion chromatograms being distinctly bi or multimodal with measured dispersities . Though NOEMA copolymerization was not ideal, the resulting series of block copolymers did exhibit the anticipated full spectrum of nanoparticle morphologies (spheres, worms, and vesicles). Interestingly, these morphology transitions occurred over a relatively narrow range of block copolymer compositions. In the case of POEMA, copolymerization was also poorly controlled with 1.50 ≤ ĐM ≤ 1.83 for the series of DMAEMA20-b-POEMAy copolymers. In contrast to the NOEMA-based copolymers, the POEMA series only yielded nanoparticles with a spherical morphology whose size increased with increasing average degrees of polymerization of the POEMA block. Collectively, though both NOEMA and POEMA can be utilized in ethanolic RAFT dispersion polymerization formulations, these preliminary studies suggest that neither appears to be an ideal aryl methacrylate choice as comonomer, especially if the goal is to combine the synthesis of well-defined copolymers with efficient nanoparticle formation.

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Cyclic Block Copolymer Microchannel Fabrication and Sealing for Microfluidics Applications

Inventions ◽

10.3390/inventions3030049 ◽

2018 ◽

Vol 3 (3) ◽

pp. 49 ◽

Cited By ~ 2

Author(s):

Chia-Yi Yen ◽

Moh-Ching Chang ◽

Zong-Fu Shih ◽

Yi-Hsing Lien ◽

Chia-Wen Tsao

Keyword(s):

Block Copolymer ◽

Chemical Resistance ◽

Microfluidic Devices ◽

Cyclic Olefin ◽

New Class ◽

Front End ◽

Cyclic Block ◽

Cyclic Olefin Polymers ◽

Polymer Microfabrication ◽

Cyclic Olefin Copolymers

High mechanical rigidity, chemical resistance, and ultraviolet-visible light transmissivity of thermoplastics are attractive characteristics in microfluidics because various biomedical microfluidic devices require solvent, acid, or base manipulation, and optical observation or detection. The cyclic block copolymer (CBC) is a new class of thermoplastics with excellent optical properties, low water absorption, favorable chemical resistance, and low density, which make it ideal for use in polymer microfluidic applications. In the polymer microfabrication process, front-end microchannel fabrication and post-end bonding are critical steps that determine the success of polymer microfluidic devices. In this study, for the first time, we verified the performance of CBC created through front-end microchannel fabrication by applying hot embossing and post-end sealing and bonding, and using thermal fusion and ultraviolet (UV)/ozone surface-assist bonding methods. Two grades of CBC were evaluated and compared with two commonly used cyclic olefin polymers, cyclic olefin copolymers (COC), and cyclic olefin polymers (COP). The results indicated that CBCs provided favorable pattern transfer (>99%) efficiency and high bonding strength in microchannel fabrication and bonding procedures, which is ideal for use in microfluidics.

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