Temperature‐Induced Phase Transition Characterization of Responsive Polymer Brushes Grafted onto Nanoparticles

Abstract

Under vigorous stirring, 875 µL of (II) was added to (I) and left at high stirring speed for 5 min. The authors would like to apologize for any inconvenience this mistake may have caused.

Thermodynamic Parameters of Temperature‐Induced Phase Transition for Brushes onto Nanoparticles: Hydrophilic versus Hydrophobic End‐Groups Functionalization

“…Materials and the analytical methods used for the synthesis characterization of AuNR and NIPAm‐PNIPAm‐SH free polymers and brushes onto AuNR are presented in subsections S1.1–S1.5 (Supporting Information). AuNR were synthesized according to a seed‐mediated growth method reported earlier (see Subsection S1.6, Supporting Information) . The synthesis of NIPAm‐PNIPAm‐SH and modification of AuNR with this polymer is discussed in subsections S1.7 and S1.8 (Supporting Information).…”

“…The investigation of temperature‐induced phase transition for free polymer and grafted brushes in D 2 O was made using T 2 ‐editing of spectral integral intensity of 1 H HRMAS NMR spectra of PNIPAm in the aliphatic region . This procedure enhances the sensitivity of the phase transition to the changes in the polymer conformation via side‐chain dynamics compared to the previous reported method .…”

“…For basic understanding and applications, it is important to quantify thermodynamic parameters of the temperature‐induced phase transition process. It was shown that for free PNIPAm polymers in aqueous solution the phase transition temperature depends on the molecular weight and the hydrophilic or hydrophobic end functionalization . In the case of hydrophilic end groups the transition temperature decreases with the increase of molecular weight, while for hydrophobic end functionalization the inverse effect is observed .…”

“…In the case of hydrophilic end groups the transition temperature decreases with the increase of molecular weight, while for hydrophobic end functionalization the inverse effect is observed . Furthermore, the molecular weight dependences of temperature‐induced phase transition parameters in the range of molecular weight from 3600 to 30 000 g mol −1 was investigated by 1 H high‐resolution magic‐angle sample spinning (HRMAS) NMR spectroscopy for free polymers and brushes having a hydrophobic benzyl end group (Bn) at one end of PNIPAm (hereinafter, abbreviated as Bn‐PNIPAm‐SH) . The other end was functionalized by a thiol (SH) group to attach the heterotelechelic polymer covalently to the gold nanorod surface.…”

“…A novel HRMAS NMR spectroscopy method discussed in ref. was based on the transverse magnetization relaxation ( T 2 ) editing of segmental dynamics and used for the investigation of spectral integral intensity dependence on temperature. Moreover, a two‐state model was developed from first principles that allow to characterize the temperature‐induced transition by thermodynamic parameters as transition temperature ( T t ) and transition entropy (Δ S ) …”