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Internal Nanoparticle Structure of Temperature-Responsive Self-Assembled PNIPAM-b-PEG-b-PNIPAM Triblock Copolymers in Aqueous Solutions: NMR, SANS, and Light Scattering Studies.
| Content Provider | Semantic Scholar |
|---|---|
| Author | Filippov, Sergey K. Bogomolova, Anna Kaberov, Leonid I. Velychkivska, Nadiia Starovoytova, Larisa I. Černochová, Zulfiya Rogers, Sarah E. Khutoryanskiy, Vitaliy V. Cook, Michael Thomas |
| Copyright Year | 2016 |
| Abstract | In this study, we report detailed information on the internal structure of PNIPAM-b-PEG-b-PNIPAM nanoparticles formed from self-assembly in aqueous solutions upon increase in temperature. NMR spectroscopy, light scattering, and small-angle neutron scattering (SANS) were used to monitor different stages of nanoparticle formation as a function of temperature, providing insight into the fundamental processes involved. The presence of PEG in a copolymer structure significantly affects the formation of nanoparticles, making their transition to occur over a broader temperature range. The crucial parameter that controls the transition is the ratio of PEG/PNIPAM. For pure PNIPAM, the transition is sharp; the higher the PEG/PNIPAM ratio results in a broader transition. This behavior is explained by different mechanisms of PNIPAM block incorporation during nanoparticle formation at different PEG/PNIPAM ratios. Contrast variation experiments using SANS show that the structure of nanoparticles above cloud point temperatures for PNIPAM-b-PEG-b-PNIPAM copolymers is drastically different from the structure of PNIPAM mesoglobules. In contrast with pure PNIPAM mesoglobules, where solidlike particles and chain network with a mesh size of 1-3 nm are present, nanoparticles formed from PNIPAM-b-PEG-b-PNIPAM copolymers have nonuniform structure with "frozen" areas interconnected by single chains in Gaussian conformation. SANS data with deuterated "invisible" PEG blocks imply that PEG is uniformly distributed inside of a nanoparticle. It is kinetically flexible PEG blocks which affect the nanoparticle formation by prevention of PNIPAM microphase separation. |
| Starting Page | 147 |
| Ending Page | 157 |
| Page Count | 11 |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://centaur.reading.ac.uk/65646/7/acs.langmuir.6b00284.pdf |
| Alternate Webpage(s) | http://centaur.reading.ac.uk/65646/1/acs.langmuir.6b00284.pdf |
| Alternate Webpage(s) | https://eprint.ncl.ac.uk/file_store/production/242114/7220B994-2EE6-41A2-B7EA-AAA8646F8172.pdf |
| Alternate Webpage(s) | https://uhra.herts.ac.uk/bitstream/handle/2299/17369/acs_2Elangmuir_2E6b00284.pdf?sequence=2 |
| Alternate Webpage(s) | http://uhra.herts.ac.uk/bitstream/handle/2299/17369/acs_2Elangmuir_2E6b00284.pdf?sequence=2 |
| PubMed reference number | 27159129v1 |
| Alternate Webpage(s) | https://doi.org/10.1021/acs.langmuir.6b00284 |
| DOI | 10.1021/acs.langmuir.6b00284 |
| Journal | Langmuir : the ACS journal of surfaces and colloids |
| Volume Number | 32 |
| Issue Number | 21 |
| Language | English |
| Access Restriction | Open |
| Subject Keyword | Artificial nanoparticles Copolymer Magnetic Resonance Imaging Neutrons Normal Statistical Distribution Polyethylene Glycols Population Parameter Solutions Spectroscopy, Near-Infrared peginterferon alfa-2b poly-N-isopropylacrylamide |
| Content Type | Text |
| Resource Type | Article |
