Diamond Publications - Search Results

Search Again...

These results only include publications that have been reviewed and processed by Diamond Light Source. To also view papers that have not yet been processed click here.

You can use the folder icon under Actions to collate papers as required. You can then click on View Folder in the left-hand navigation to review and/or download your folder.

One item found (0 items not approved).

Instruments / Technical Area	Publication Details	Published	Actions
I22-Small angle scattering & Diffraction	Tuning the properties of hydrogen-bonded block copolymer worm gels prepared via polymerization-induced self-assembly Eleanor Raphael , Matthew J. Derry , Michael Hippler , Steven P. Armes Chemical Science DOI: 10.1039/D1SC03156B Diamond Proposal Number(s): [21776] Open Access Show Abstract ▼ Abstract: Polymerization-induced self-assembly (PISA) is exploited to design hydrogen-bonded poly(stearyl methacrylate)-poly(benzyl methacrylate) [PSMA-PBzMA] worm gels in n-dodecane. Using a carboxylic acid-based RAFT agent facilitates hydrogen bonding between neighboring worms to produce much stronger physical gels than those prepared using the analogous methyl ester-based RAFT agent. Moreover, tuning the proportion of these two types of end-groups on the PSMA chains enables the storage modulus (G’) of the 20% w/w worm gel to be tuned from ~4.5 kPa up to ~114 kPa. This is achieved via two complementary routes: (i) an in situ approach using binary mixtures of acid- and ester-capped PSMA stabilizer chains during PISA or (ii) a post-polymerization processing strategy using a thermally-induced worm-to-sphere transition to mix acid- and ester-functionalized spheres at 110 °C that fuse to form worms on cooling to 20°C. SAXS and rheology studies of these hydrogen-bonded worm gels provide detailed insights into their inter-worm interactions and physical behavior, respectively. In the case of the carboxylic acid-functionalized worms, SAXS provides direct evidence for additional inter-worm interactions, while rheological studies confirm both a significant reduction in critical gelation concentration (from approximately 10% w/w to 2-3% w/w) and a substantial increase in critical gelation temperature (from 41 °C to 92 °C). It is remarkable that a rather subtle change in the chemical structure results in such improvements in gel strength, gelation efficiency and gel cohesion.	Aug 2021

Instruments / Technical Area

Publication Details

Published

Actions

I22-Small angle scattering & Diffraction

Tuning the properties of hydrogen-bonded block copolymer worm gels prepared via polymerization-induced self-assembly

Eleanor Raphael , Matthew J. Derry , Michael Hippler , Steven P. Armes

Chemical Science

DOI: 10.1039/D1SC03156B

Diamond Proposal Number(s): [21776]