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Sep 9, 2016 · Multi-responsive (diethylene glycol) methyl ether methacrylate–methacrylic acid (DEGMA–MAA) copolymers were synthesised for the first time via RAFT polymerisation, and the structure–activity interplay of statistical and block copolymers in solution was compared.
- Temperature-responsive methacrylamide polyampholytes - RSC ...
Lucy G. Weaver, Regine Stockmann, San H. Thang and Almar...
- Temperature-responsive methacrylamide polyampholytes - RSC ...
Med Phys. 1995 Feb;22 (2):209-34. doi: 10.1118/1.597458. Authors R Nath 1 , L L Anderson , G Luxton , K A Weaver , J F Williamson , A S Meigooni
- Ravinder Nath, Lowell L. Anderson, Gary Luxton, Keith A. Weaver, Jeffrey F. Williamson, Ali S. Meigo...
- 1995
- Introduction
- Experimental
- Results and Discussion
- Conclusion
- Acknowledgements
Polymers that reversibly change their solution conformation in response to an applied external stimulus have found use in drug delivery, chromatography and tissue engineering, amongst other applications.1–4 Termed stimuli-responsive or smart polymers,5 the physical properties of these materials can be precisely controlled by modifying the external ...
Materials
N-[3-(Dimethylamino)propyl]methacrylamide (DMAPMAm), methacrylic acid (MAA) and 1,3,5-trioxane were purchased from Sigma-Aldrich. DMAPMAm and MAA were purified by running the monomer through a short column packed with hydroquinone monomethyl ether inhibitor removers (Sigma-Aldrich). N-(tert-Butyl)methacrylamide (tBMAm) was purchased from TCI Chemicals and was used as received. 4-((((2-Carboxyethyl)thio)carbonothioyl)thio)-4-cyanopentanoic acid (CETCPA) was obtained from Boron Molecular (BM143...
Instrumentation
Gel Permeation Chromatography (GPC) for all polymers was carried out on a Waters Alliance system equipped with an Alliance 2695 Separations Module (integrated quaternary solvent delivery, solvent degasser and autosampler system), a Waters column heater module, a Waters 2414 RDI refractive index detector, a Waters PDA 2996 photodiode array detector (210–400 nm at 1.2 nm) and 2 × Agilent PL-Aquagel columns (PL-Aquagel Mixed H (8 μm)), each 300 mm × 7.8 mm2, providing an effective molar mass ran...
General procedure for the preparation of statistical copolymers via RAFT
Weighed quantities of monomers (DMAPMAm, MAA and tBMAm), RAFT agent (CETCPA), initiator (ACVA) and the internal standard (1,3,5-trioxane) were combined into 25 mL screw-top vials and diluted with solvent (either Milli-Q grade water, 1,4-dioxane, or glacial acetic acid) to a set concentration (usually 2.0 M). Each mixture was agitated to solubilise all components and a small aliquot was taken from each vial for NMR analysis (t = 0 time point). A rubber septum was then fitted to the top of each...
Polymer synthesis
Using a combination of N-[3-(dimethylamino)propyl]methacrylamide (DMAPMAm) and methacrylic acid (MAA) as the basic and acidic comonomers, respectively, we report a set of polyampholytes that have increasing amounts of N-(tert-butyl)methacrylamide (tBMAm) incorporated as the hydrophobic comonomer. All polymers were synthesised from a combination of DMAPMAm, MAA and tBMAm monomers, via RAFT polymerisation34 using 4-((((2-carboxyethyl)thio)carbonothioyl)thio)-4-cyanopentanoic acid (CETCPA) as th...
Temperature-responsive properties of polymers A1–A8
The temperature-responsive properties of polymers A1–A8 at concentrations of 1.0, 2.5, 5.0 and 10.0 mg mL−1 in Milli-Q grade water were determined via UV-Vis spectroscopy (500 nm) at a heating/cooling rate of 1.0 °C min−1 over the temperature range of 15–100 °C. For each sample, the absorbance was measured and converted to the recommended percent transmittance (% T) values,19 and the cloud point temperature (TCP) values were determined as described in the Experimental section. The heating cur...
pH and salt effects on the polymer cloud points
By incorporating a balance of acidic and basic comonomers into the polymer chains, it was expected that these polymers would display additional responsiveness to changes in pH. To test this hypothesis, each polymer A1–A8 was dissolved at a concentration of 1 mg mL−1 in 10 mM buffer solutions that had been adjusted to pH 3, 7, and 10 (see Experimental section for buffer details). These values were selected as the pH extremities 3 and 10 were greater than the pKa's of each of the monomers in th...
A series of N-[3-(dimethylamino)propyl]methacrylamide (DMAPMAm), methacrylic acid (MAA) and N-(tert-butyl)methacrylamide (tBMAm) terpolymers were synthesised via RAFT polymerisation. Polymer synthesis in a variety of solvents was trialled, and glacial acetic acid was determined to be the best solvent during this synthesis as the polymers obtained h...
The authors wish to acknowledge funding from the CSIRO's Office of the Chief Executive (OCE). Many thanks to Dr Roger Mulder for his help with the NMR experiments and subsequent analyses, and to Dr David Alexander for his help with the data analysis of the cloud point temperatures versusmolar ratio of tBMAm content.
- Lucy G. Weaver, Regine Stockmann, San H. Thang, San H. Thang, Almar Postma
- 2017
L.G. Weaver is the author of Out of Bounds (5.00 avg rating, 2 ratings, 0 reviews, published 1978)
- (2)
Generalizability of algorithms for binary cancer vs. no cancer classification is unknown for clinically more significant multi-class scenarios where intermediate categories have different risk factors and treatment strategies. We present a system that classifies whole slide images (WSI) of breast bi ….
- Baris Gecer, Selim Aksoy, Ezgi Mercan, Linda G. Shapiro, Donald L. Weaver, Joann G. Elmore
- 2018
L G WEAVER LIMITED - Free company information from Companies House including registered office address, filing history, accounts, annual return, officers, charges, business activity.
Gregory L. Weaver joined the Senior Professional Staff of JHU/APL in 2003 and works within the RF Engineering Group of the Space Department. He is a technologist with extensive background in the technical and business aspects of the frequency control industry and has held positions as a senior design engineer, technical manager and marketing ...
