Supporting information Temperature and ph-dual Responsive AIE-Active Core Crosslinked Polyethylene Poly(methacrylic acid) Multimiktoarm Star Copolymers ` Zhen Zhang,*,, and Nikos Hadjichristidis*, School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, China Physical Sciences and Engineering Division, KAUST Catalysis Center, Polymer Synthesis Laboratory, King Abdullah University of Science and Technology (KAUST), Thuwal 23955, Saudi Arabia S1
Experimental Section Materials Copper (I) bromide (CuBr, 99.999%), N, N, N, N, N -pentamethyldiethylenetriamine (PMDETA, 99%, Aldrich), ethyl 2-bromoisobutyrate (EBiB, 98%) and hydrochloride acid solution (32 wt. % in water) were purchased from Aldrich and used as received. tert-butyl methacrylate (tbma, 98%) was distilled over calcium hydride (CaH2) under reduced pressure. Tetrahydrofuran (THF) and toluene were refluxed over sodium/benzophenone and distilled under a nitrogen atmosphere just before use. 1,4-Dioxane was used as received. Cross-linker TPE-2St and linear polyethylene macroinitiator PE-Br were synthesized according to our previous work (Macromolecules 2017, 50, 4217). PtBMA-Br (Mn,NMR = 2470, Đ = 1.29) was prepared according to the typical ATRP procedure initiated by ethyl α-bromoisobutyrate with CuBr/PMDETA as catalyst. Characterization The 1 H and 13 C NMR spectra were recorded with a Bruker AVANCE III-600 spectrometer. Fourier transform infrared spectra (FT-IR) were obtained from Thermo Scientific Nicolet is10 spectrometer. The molecular weight (Mn,GPC) and dispersity (ĐRI) of PtBMA were determined by gel permeation chromatography (GPC) (Viscoteck 305 instrument with two columns of Styragel HR2 and Styragel HR4) with THF eluent at 35 o C, flow rate = 1.0 ml/min and differential refractive index (RI) detector. The apparent molecular weight (Mn,RI) and dispersity (ĐRI) of star polymers were measured on a Viscoteck high temperature gel permeation chromatography (HT- GPC) module 350 instrument with two PLgel 10 µm MIXED-B columns and 1,2,4- trichlorobenzene (TCB) as the eluent at a flow rate of 0.8 ml/min at 150 ºC with differential S2
refractive index (RI) detector. It was calibrated by linear polystyrene (PS) standards. The absolute molecular weight (Mw,GPC-LS) of star polymers and ĐGPC-LS were determined by triple-detection HT-GPC (refractometry, light scattering at λ = 670 nm and viscometry). It was calibrated by PS standard (Mw = 115 10 3 g/mol, Đ = 1.05). Transmittance measurements were performed on a Thermo Evolution 600 UV-Vis spectrophotometer in quartz cuvettes of 10 mm path length at a wavelength of 500 nm at room temperature. Photoluminescence spectra were recorded on a Thermo Lumina Fluorescence Spectrometer equipped with an external water circulator for the thermostatted cell holder. Dynamic light scattering (DLS) measurements were made with a Brookhaven BI-200SM multi-angle goniometer with a TurboCorr correlator. The light source was a 30 mw He Ne laser emitting vertically polarized light of 632.8 nm wavelength. Synthesis of miktoarm star copolymers (PE)n-(PtBMA)m-P(TPE-2St) As an example, the synthesis of (PE)19.4-(PtBMA)14.5-P(TPE-2St) star is given. CuBr (28 mg, 0.20 mmol), TPE-2St (0.90 g, 1.5 mmol), PE1.6k-Br (0.16 g, 0.10 mmol, Mn,NMR =1610, Đ = 1.16), PtBMA-Br (0.25 g, 0.10 mmol, Mn,NMR = 2470, Đ = 1.29) and toluene (14 ml) were placed into a 100 ml Schlenk flask. The mixture was subjected to three freeze-pump-thaw cycles and then PMDETA (84 µl, 0.40 mmol) was added and the mixture was subjected to another one freezepump-thaw cycle. The solution was immediately immersed into an oil bath set at 100 o C to start the polymerization under stirring. After 26 h, the polymerization was stopped by cooling in a liquid nitrogen bath. The cloudy solution was heated to clear and poured into cold methanol (300 ml) with stirring. The solid was filtered, washed with methanol, dried under vacuum, and characterized by 1 H NMR and HT-GPC (0.90 g, Mw,GPC-LS = 218 10 3, ĐGPC-LS= 1.52). Hydrolysis of (PE)n-(PtBMA)m-P(TPE-2St) to (PE)n-(PMAA)m-P(TPE-2St) S3
As an example, the hydrolysis of (PE)19.4-(PtBMA)14.5-P(TPE-2St) star polymer to (PE)19.4- (PMAA)14.5-P(TPE-2St) is given. A mixture of (PE)19.4-(PtBMA)14.5-P(TPE-2St) (0.20 g, ~ 0.018 mmol of ester), 1,4-dioxane (5.0 ml), and hydrochloride acid solution (6 M, 3.0 ml, 18 mmol) was refluxed for overnight. Then, the solution was poured into methanol (200 ml) with stirring. The solid was filtered, washed with H2O (2 10 ml), methanol (2 10 ml), dried under vacuum, and characterized by 1 H NMR and FT-IR. Figure S1. GPC (THF at 35 o C, PS standards) trace of linear PtBMA-Br S4
Figure S2. 1 H NMR (600 MHz) spectra of a) TPE-2St in chloroform-d at 25 o C, b) PE-Br and (PE) n- (PtBMA) m-p(tpe-2st) in 1,1,2,2-tetrachloroethane-d 2 at 90 o C. S5
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Figure S3. 1 H NMR spectra (600 MHz) of (a) (PE) 14.2-(PtBMA) 22.8-P(TPE-2St) (Table 1, entry 1); (b) (PE) 25.5- (PtBMA) 8.6-P(TPE-2St) (Table 1, entry 2); (c) (PE) 29.0-(PtBMA) 42.6-P(TPE-2St) (Table 1, entry 4) and (d) (PE) 19.4-(PtBMA) 14.5-P(TPE-2St) (Table 1, entry 5) in 1,1,2,2-tetrachloroethane-d 2 at 90 o C. S7
Figure S4. HT-GPC (TCB at 150 o C) traces of linear PE 2.5k-Br and the corresponding (PE) 14.2-(PtBMA) 22.8- P(TPE-2St) stars (The negative peak of PE 2.5k-Br is due to the negative DRI of PE) Figure S5. HT-GPC (TCB at 150 o C) traces of linear PE 1.2k-Br and the corresponding (PE) 25.5-(PtBMA) 8.6- P(TPE-2St) stars (The negative peak of PE 1.2k-Br is due to the negative DRI of PE) S8
Figure S6. DLS measurements of the (PE) 19.4-(PMAA) 14.5-P(TPE-2St) stars in THF-buffer mixture (10/90 vol%, polymer concentration: 0.05 g/l) at different ph (D: particle diameter in nm). Figure S7. Particle size distributions of (PE) 19.4-(PMAA) 14.5-P(TPE-2St) stars in THF-buffer mixture (10/90 vol%, polymer concentration: 0.05 g/l) at ph = 4.1-12.2 (a-i). S9