Temperature-responsive star-shaped poly(2-ethyl-2-oxazoline) and poly(2-isopropyl-2-oxazoline) with central thiacalix[4]arene fragments: structure and properties in solutions

Star-Shaped Poly(2-ethyl-2-oxazoline) and Poly(2-isopropyl-2-oxazoline) with Central Thiacalix[4]Arene Fragments: Reduction and Stabilization of Silver Nanoparticles

“…As was established earlier [15], star-PETOX and star-PIPOX macromolecules demonstrate multilevel organization in water solutions. Distributions of hydrodynamic radii obtained by DLS for star-PETOX solutions indicate the presence of particles with hydrodynamic radii of about 5 nm and 25 nm.…”

“…Star-shaped poly(2-ethyl-2-oxazoline) (star-PETOX) and poly(2-isopropyl-2-oxazoline) (star-PIPOX) (see Scheme 1) with arms grafted to the lower rim of thiacalix[4]arene were synthesized according to the procedure reported previously [15]. Star polymers contain four arms, the average degree of polymerization of PETOX chains in the star-PETOX macromolecules was 16 monomer and for PIPOX in star-PIPOX macromolecule was 7 monomer units per 1 arm.…”

“…Table 2 presents the characteristics calculated by this method for solutions of star-PETOX/Ag 0 and star-PIPOX/Ag 0 complexes prepared at various n Ag /n S ratios. where aggregation is absent [15]. The detailed information on velocity sedimentation data is presented in Table S1 (Supplementary Materials).…”

“…However, the extremely low water solubility of simple calixarenes prevents their use in biomedical applications. The addition of amphiphilic polymeric "arms" to calixarene macrocycles may solve the problem of their high hydrophobicity and, at the same time, help to realize the beneficial properties of both classes of compounds.Temperature-responsive star-shaped poly(2-ethyl-2-oxazoline) (star-PETOX) and poly(2-isopropyl-2-oxazoline) (star-PIPOX) with polymeric arms grafted to the lower rim of thiacalix[4]arene have been recently investigated in water and tetrahydrofuran solutions [15]. It was established that in tetrahydrofuran, the studied polymers are present only in the form of individual macromolecules, while in water, in addition to isolated molecules, large aggregates were found.…”

“…Temperature-responsive star-shaped poly(2-ethyl-2-oxazoline) (star-PETOX) and poly(2-isopropyl-2-oxazoline) (star-PIPOX) with polymeric arms grafted to the lower rim of thiacalix[4]arene have been recently investigated in water and tetrahydrofuran solutions [15]. It was established that in tetrahydrofuran, the studied polymers are present only in the form of individual macromolecules, while in water, in addition to isolated molecules, large aggregates were found.…”