![]() ![]() ![]() Some societies use Oxford Academic personal accounts to provide access to their members. If you do not have a society account or have forgotten your username or password, please contact your society. ![]() Do not use an Oxford Academic personal account. When on the society site, please use the credentials provided by that society.If you see ‘Sign in through society site’ in the sign in pane within a journal: Many societies offer single sign-on between the society website and Oxford Academic. Society member access to a journal is achieved in one of the following ways: If you cannot sign in, please contact your librarian. If your institution is not listed or you cannot sign in to your institution’s website, please contact your librarian or administrator.Įnter your library card number to sign in. Following successful sign in, you will be returned to Oxford Academic.When on the institution site, please use the credentials provided by your institution.Select your institution from the list provided, which will take you to your institution's website to sign in.Click Sign in through your institution.Shibboleth / Open Athens technology is used to provide single sign-on between your institution’s website and Oxford Academic. This authentication occurs automatically, and it is not possible to sign out of an IP authenticated account.Ĭhoose this option to get remote access when outside your institution. Typically, access is provided across an institutional network to a range of IP addresses. If you are a member of an institution with an active account, you may be able to access content in one of the following ways: Acetonide groups on the dendron were deprotected to afford hydroxylated polymer that showed well-defined morphologies above the LCST and after heating-cooling cycle while significant dye encapsulation was seen only above the LCST.Get help with access Institutional accessĪccess to content on Oxford Academic is often provided through institutional subscriptions and purchases. The azobenzene unit was found to undergo trans-cis photoisomerization in the assemblies and caused a change in the microenvironment of an encapsulated hydrophobic dye without any release. ![]() Complete change in morphology of the two polymers into large spherical aggregates and nan-otubes, respectively, was observed upon heating the micellar solution above LCST. Two polymers obtained by varying the chain length of the PNIPAM block showed different morphologies and lower critical solution temperature (LCST) values in aqueous solution. Linear PNIPAM precursor was prepared from an azide-functionalized azobenzene containing ATRP initiator. In the other cases, only a partially disaggregation process takes place.Īmphiphilic temperature-and photoresponsive linear-dendritic block copolymers comprising second-generation acetonide-2,2-bis-methylolpropionic acid-based polyester dendron and linear poly(N-isopropyl acrylamide) (PNIPAM) linked by an azobenzene unit were synthesized using atom transfer radical polymerization (ATRP) followed by click chemistry. A total micelles disaggregation was obtained for the polysiloxane modified with azophenol and amine containing a long hydrocarbon segment. The disaggregation processes of the micelles under UV irradiation reveal that the polymer chemical structure influences the aggregates stability. The clusters' dimension cannot be controlled, the polydispersity index having high values. As a function of the ternary amine structure used in the quarterisation reaction, the micellar aggregation process is different, individual micelles or micellar clusters being obtained. All the amphiphilic polysiloxanes are capable of generating micelles, the critical concentration of the aggregation values being situated in the range 10−3–10−2 g/L. The structure of the polysiloxanes and their aggregation/disaggregation capacity were evaluated by 1H-NMR, DSC, fluorescence and UV–VIS spectroscopy, dynamic light scattering and transmission electron microscopy. In the first step, the polysiloxane was modified with azo-aromatic groups (35–45% substitution degree) and in the second step the unreacted chlorobenzyl groups were quaternized, using different tertiary amines. The amphiphilic polymers were synthesized in a two-step reaction, starting from a polysiloxane containing chlorobenzyl groups in the side chain. Photosensitive micelles based on amphiphilic azo-polysiloxanes were obtained and characterized. ![]()
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