Supporting information ontrollable and stable deformation of a self-healing photo-responsive supramolecular assembly for an optically actuated manipulator arm Qianyu Si, a Yiyu Feng, a,c,d * Weixiang Yang, a Linxia Fu, a Qinghai Yan a, Liqi Dong, a Peng Long, a and Wei Feng a,b,c,d a School of Materials Science and Engineering, Tianjin University, Tianjin 300072, P. R hina. b ollaborative Innovation enter of hemical Science and Engineering (Tianjin), Tianjin 300072, P. R hina. c Key Laboratory of Advanced eramics and Machining Technology, Ministry of Education, Tianjin 300072, P. R hina. d Tianjin Key Laboratory of omposite and Functional Materials, Tianjin 300072, P. R hina. *orresponding author s Email: fengyiyu@tju.edu.cn S-1
MATERIALS AD METHDS Materials. 2-Amino-4-hydroxy-6-methylpyrimidine, hexane 1,6-diisocyanate (HDI), 5-aminoisophthalic acid and isophthalic acid were purchased from J&K hemical. Polyacrylic acid (PAA) with a number average molecular weight of 450000 g/mol and a polydispersity index of 1.25 was received from Shanghai Yuanye Bio-Technology o., Ltd.,-Dimethylformamide (DMF) and -methyl-2-pyrrolidinone (MP) were purified by distillation. Dibutyltindilaurate (DBTDL) and sodium nitrite (a 2 ) were purchased from Aladdin Industrial orporation. Synthesis of 2-(6-Isocyanatohexylaminocarbonylamino)-6-methyl-4[1H]pyrimidinone (UPy-) (Scheme S1(A)). 2-amino-4-hydroxy-6-methylpyrimidine (2.91 g, 0.023 mol) was added to HDI (0.162 mol, 26 ml). Then, the solution was heated at 100 º for 16 h under nitrogen. After the completion of the reaction, petroleum ether was added and the resulting precipitate was filtered and washed thrice with petroleum ether. The obtained white powder was dried at 50 º under reduced pressure for 12 h. The excess HDI was recovered by distillation. Yield: 97%. IR (KBr): ν = 1675, 1701, 2279, 3233, 3466 cm -1. 1 H MR (400 MHz, Dl 3, δ): 13.03 (s, 1H, H 3 H), 11.79 (s, 1H, H 2 H(=)H), 10.11 (s, 1H, H 2 H(=)H), 5.75 (m, 1H, H=H 3 ), 3.21 (m, 4H, H(=)HH 2 + H 2 ), 2.16 (d, 3H, H 3 =H), 1.54 (s, 4H, H 2 H 2 + HH 2 H 2 ), 1.34 (m, 4H, HH 2 H 2 H 2 H 2 H 2 ). 13 MR (100 MHz, Dl 3, δ): 172.8, 156.3, 150.6, 121.6, 118,106.4, 45.5, 42.6, 39.5, 35.5, 30.9, 29.1, 18.7. Synthesis of t-azo (Scheme S1(B)). 5-Aminoisophthalic acid (2.715 g, 15 mmol) and a 2 (1.24 g, 18 mmol) were dissolved in aqueous ah solution (40 ml, 1 mol/l) and the mixture S-2
was slowly added to an Hl solution (85 ml, 1 mol/l) in an ice bath at 0 5 º to obtain the diazonium salt. Meanwhile, isophthalic acid (2.5 g, 15 mmol) and ah (1.2 g, 30 mmol) were dissolved in 100 ml of distilled water. The solution of the diazonium salt was slowly added to the isophthalic acid solution and the ph of the reaction mixture was adjusted to 7 9 by the dropwise addition of ah 3 and it was allowed to react overnight at 0 5 º under the protection of argon. Subsequently, the reaction mixture was acidified slowly with 1 M HL (90 ml). The precipitate was collected, washed with water, and dried to obtain a solid. The resulting product was purified by recrystallization from a mixture of ethanol and distilled water (1:1 v/v). The final solid was collected by filtration, washed with deionized water, and dried overnight under vacuum at 60 º to obtain t-azo as a red-orange solid in 50% yield (2.7 g, 7.5 mmol). IR (KBr): ν = 1704, 1403, 920 cm -1. 1 H MR (400 MHz, DMS-d 6, δ) 13.57 (s, 4H, H), 8.62 (d, 4H, H--H--=), 7.68 (t, 2H, H--H--H). Synthesis of PAA-u (Scheme S1()). Polyacrylic acid (450 mg, 1 10-3 mol) was dissolved in DMF (50 ml) together with 3 drops of dibutyltindilaurate in a 100 ml round-bottom flask. To this solution, UPy- (20, 80, or 160 mol%) was added. The mixture was refluxed at 100 º for 16 h with stirring under an argon atmosphere, to yield a viscous faint yellow liquid. After the reaction, most of the unreacted UPy- was filtered off. The crude product was then dissolved in DMF (50 ml) and treated with silica (2.0 g) in the presence of 1 drop of dibutyltindilaurate for 60 º for 1 h. The silica was removed by filtration and the solution was washed thrice with dichloromethane. The resulting product was dried for 2 days at 50 º under reduced pressure to remove dichloromethane to obtain a pale yellow solid in 80% yield. Three products with different amounts of grafted UPy were obtained. 1 H MR (400 MHz, DMS-d 6, δ): 13.03 (s, 1H, H 3 H), 11.79 S-3
(s, 1H, H 2 H(=)H), 10.11 (s, 1H, H 2 H(=)H), 12.27 (s, 1H, H), 7.95 (s, 1H, =-H-), 5.76 (d, J = 3.3 Hz, 1H, H 3 --H), 3.21 (s, 7H, -H 2 -H 2 -H 2 -H 2 -H 2 -H 2 -H+ -H 2 -H-H+ -H 2 -H-H), 2.81 (d, J = 63.9 Hz, 3H, H 3 -H-H), 2.38 0.56 (s, 8H, -H 2 -H 2 -H 2 -H 2 -H 2 -H 2 -). Instruments and Measurements. FTIR spectra were recorded on a Bruker Tensor 27 spectrometer using discs of KBr with the compound to be analyzed. 1 H-MR (400 MHz, 200 scans) and 13 -MR (400 MHz, 2000 scans) spectra were recorded in Dl 3 and d-dms at room temperature using trimethylsilyl as the internal standard using a Bruker Avance Ⅲ 400 MH. X-ray photoelectron spectroscopy (XPS) was performed on a PHI 1600 model surface analysis system using a 450 W Mg Kα source. Differential scanning calorimetry (DS TA Q20) was carried out to analyze the hydrogen bonding. The process is as follows: Samples (10 mg) were added into aluminum pans. Then, the pan was sealed and weighed. The method used for DS test is as follows: Equilibration at 25º followed by heating to 200º at a rate of 5º min -1 and then cooling to room temperature at 5º min -1. A Hitachi 330 UV-vis spectrophotometer was used to record the time-evolution of the UV-vis absorption spectra of DMF solution and films of t-azo and PAA-u/t-Azo. The samples were first irradiated by a 532 nm green laser (STEMT 2 5) at an intensity of 310 mw cm -2 with the light source positioned at a distance of 2 cm from the sample at 30º. Then, the film was irradiated by 365 nm UV light (LED-200) with the intensity of 30 mw cm -2 measured by a light density meter (Beijing Zhongjiaojinyuan o., Ltd.). The cis-to-trans thermal reversion process was also investigated by the UV/Vis spectroscopy after the samples were stored in darkness, after covering with aluminum foils. S-4
Synthesize of the monomers and polymers H H 2 100 12h 2 H H H A H 2 H H H 2 0 H H B H H H H H H H H 2 H n H H H DMF 100 16h H 2 H H H 2 H H n 6 H 12 H H H Scheme S1. Synthetic route of the monomers and polymers. S-5
Figure S1. The schematic illustration of photo-induced driving forces. S-6
Transmittance(a.u.) UPy- PAA H PAA-u -H -H - 2270 -H -H H -H 4000 3500 3000 2000 1500 1000 500 Wavenumbers(cm -1 ) Figure S2. FT-IR spectra of UPy-, PAA, and PAA-u. S-7
(a) PAA (b) UPy- (c)paa-u Figure S3. XPS spectra of PAA, UPy- and PAA-u (a) PAA, (b) UPy- and (c) PAA-u prepared with 20 mol% UPy- with respect to PAA. S-8
Endo. Endo. Endo. Endo. Endo. Endo. Endo. Endo. (a) 5 /min, 3rd scan PAA (a) (b) 5 /min, 3rd scan 5 /min, 3rd scan PAA t-azo (b) Tg 20 40 60 80 100 120 140 160 180 Temperature ( ) (a) (c) 20 40 40 60 60 80 80 100 100120120 140 140 160 160 180 180 Temperature/ ( ) 5 /min, 3rd scan 5 /min, 3rd scan PAA-u/t-Azo PAA Tg (b) (c) 20 40 5 /min, 3r 5 /min, t-azo 3rd PAA-u/t-A Figure S4. DS curves of PAA t-azo and PAA-u /t-azo cooling and heating run of (a) PAA, (b) t-azo, and (c) PAA-u/t-Azo at the rate of 5 º /min. Tg 20 40 40 60 60 80 80 100 100120 120 140 140 160 160 180 180 Temperature ( ) ( ) (c) 20 40 60 80 100 120 140 160 20 40 60 80 100 120 140 Temperature/ 160 1 Temperature ( ) 5 /min, 3rd scan S-9
Intensity(a.u.) (a) 4t 1t UV initial green 2t 3t 1c 4c 2c 3c 4 1 3 2 8.7 8.6 8.5 8.2 8 7.8 7.6 7.4 ppm 1.7 t-azo (b) 1.6 1.5 1.4 I= - 9.45 10-3 +1.72 5 10 15 20 25 30 35 40 ontent of c-isomer(%) Figure S5. (a) 1 H-MR of t-azo in three states: before irradiation, after green laser irradiation and then after UV irradiation, (b) the curve of content of c-isomer and intensity of t-azo and PAA-u/t-Azo film. S-10
Absorbance(a.u.) Absorbance(a.u.) Absorbance(a.u.) Absorbance(a.u.) Absorbance(a.u.) Absorbance(a.u.) (a) (c) 1.8 1.5 1.2 0.9 0.6 (a) 1.8 1.5 1.2 0.9 0.6 Figure S6. Time-evolution of the absorption spectra of t-azo in DMF (a) under the irradiation of green laser at 532 nm, (b) UV light at 365 nm after the irradiation of green laser, and (c) in darkness after irradiation by the UV light. 20s 15s 10s 5s 0s (b) 1.8 1.5 1.2 0.9 0.6 0.3 0.3 0.3 0.3 270 300 330 360 390 270 420 300 450 330 360 390 270 420 300 450 330 360 390 270 420 300 450 330 360 390 420 450 Wavelength(nm) Wavelength(nm) Wavelength(nm) Wavelength(nm) 1.8 1.8 (c) Initial (d) 2.1 Initial (d) 2.1 green laser green laser 1.5 40h 1.8 Kp1=7.5 10-2 S -1 UV light 1.5 40h 1.8 Kp1=7.5 10-2 S -1 UV light darkness 20h darkness 20h 10h 1.5 10h 1.5 1.2 1.2 5h 5h Kr=2.1 10 1h 1.2-2 S -1 Kr=2.1 10 1h 1.2-2 S -1 0h 0h 0.9 0.9 0.9 0.9 0.6 0.6 0.6 0.6 0.3 0.3 Kp2=6.65 10-6 S -1 Kp2=6.65 10-6 S -1 0.3 0.3 0.0 0.0 270 300 330 360 390270420300450330 360 390 0 30420 60 90 450120 60000 0 30 60 120000 90 120 60000 120000 Wavelength(nm) Wavelength(nm) Time(s) Time(s) ln[(a 0 -A )/(A t -A )] 20s 15s 10s 5s 0s (b) ln[(a 0 -A )/(A t -A )] 1.8 1.5 1.2 0.9 0.6 0s 10s 20s 30s 40s 60s 120s 180s 0s 10s 20s 30s 40s 60s 120s 180s S-11
Absorbance(a.u.) 1.5 1.0 0.5 0.0 0.12 0.08 0.04 0.00-0.04 320 340 360 PAA -0.5 210 280 350 420 490 560 Wavelength(nm) Figure S7. Time-evolution of the absorption spectra of PAA in DMF S-12
Absorbance of λ λmax at 340nm max at 340nm 1.24 1.23 E-rich state(green laser) Figure S8. Multiple Z-E isomerization cycles of the PAA-u/t-Azo film monitored by recording the absorbance at 340 nm after green laser irradiation for 60 s and then after UV irradiation for 4 min over 100 cycles. 1.22 1.21 1.20 1.19 1.18 1.17 Z-rich state(uv light) 0 10 20 30 40 80 90 100 umber of cycles S-13
Stress (MPa) 30 20 initial film green light UV light 10 Figure S9. The stress & strain of the PAA-u/t-Azo finger of initial film, irradiated by green light and UV light. 0 0.0 0.5 1.0 1.5 2.0 2.5 Strain (%) S-14
(a) (b) Figure S10. The high-resolution IR image of the PAA-u/t-Azo finger (a) before irradiation (b) during irradiated by green laser. S-15
(a) (b) 80 mw/cm 2 127 mw/cm 2 58 68 (c) 310 mw/cm 2 (d) 563 mw/cm 2 72 80 Figure S11. The high-resolution IR images of the PAA-u/t-Azo arm irradiated by different intensities green laser (a) 80 mw/cm 2, (b) 127 mw/cm 2, (c) 310 mw/cm 2, (d) 563 mw/cm 2. S-16
Table S1. Elemental composition of PAA, UPy-, and PAA-u (20). Sample Si Grafting Weight (at.%) (at.%) (at.%) (at.%) rate ratio PAA 70.68 29.32 UPy- 65.81 12.7 20.43 1.06 PAA-u (20) 63.47 23.04 3.96 9.54 23 8 S-17
Table S2. Driving forces of different intensities lights. intensity (green laser) driving force intensity (UV light) driving force (mw/cm 2 ) () (mw/cm 2 ) () 80 3.2 10-6 25 1.6 10-6 127 6.2 10-6 30 3.6 10-6 310 1.4 10-5 62 5.6 10-6 563 1.7 10-5 102 1.1 10-5 S-18