Janus [3:5] Polystyrene-Polydimethylsiloxane Star Polymers with a Cubic Core

Transcription

1 Supporting Information for Janus [3:5] Polystyrene-Polydimethylsiloxane Star Polymers with a Cubic Core Peng-Fei Jin, 1# Yu Shao, 1,2# Guang-Zhong Yin, 1 Shuguang Yang, 2 Jinlin He, 3 Peihong Ni, 3 Wen-Bin Zhang*,1 1 Key Laboratory of Polymer Chemistry & Physics of Ministry of Education, Center for Soft Matter Science and Engineering, College of Chemistry and Molecular Engineering, Peking University, Beijing , P. R. China 2 State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Center for Advanced Low-dimension Materials, Donghua University, Shanghai , P. R. China 3 College of Chemistry, Chemical Engineering and Materials Science, State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials, Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application, Suzhou Key Laboratory of Macromolecular Design and Precision Synthesis, Soochow University, Suzhou , P. R. China wenbin@pku.edu.cn (W.-B. Zhang)

2 Experimental Section Chemicals and Solvents. The following chemicals were used as received: octavinylposs (V8T8, 98%, Beijing HWRK Chemical Co., LTD), triflic acid (TfOH, 95%, J&K Chemicals), 4-pentynoic acid (97%, J&K Chemicals), 2,2'- Dithiodiethanol (DTT, 99%, for electrophoresis, J&K Chemicals), 4-dimethylaminopyridine (DMAP, 98%, J&K Chemicals ), N,N -diisopropylcarbodiimide (DIPC, 98%, TCI Chemicals), triethylamine(et3n, 99%, Sinopharm Chemical Reagent), 2,2-dimethoxy-2-phenylacetophenone (DMPA, 97%, J&K Chemicals), oxalyl chloride (A.R., Sinopharm Chemical Reagent), N, N, N, N, N -pentamethyl diethylenetriamine (PMDETA, 95%, TCI Chemicals ), hydrochloric acid (HCl, A.R., Sinopharm Chemical Reagent), sodium carbonate (Na2CO3, A.R., Sinopharm Chemical Reagent), sodium bicarbonate (NaHCO3, A.R., Sinopharm Chemical Reagent), sodium chloride (NaCl, A.R., Sinopharm Chemical Reagent), sodium sulfate (Na2SO4, A.R., Sinopharm Chemical Reagent), sodium azide (NaN3, A.R., Sinopharm Chemical Reagent), N, N - dimethylformamide (DMF, A.R., Sinopharm Chemical Reagent), chloroform (CHCl3, A.R., Beijing Tongguang Industry of Fine Chemicals Company), tetrahydrofuran (THF, A.R., Sinopharm Chemical Reagent), petroleum ether (PE, 95%, b.p C, Beijing Tong-guang Industry of Fine Chemicals Company), ethyl acetate (EA, A.R., Beijing Tong-guang Industry of Fine Chemicals Company), methanol (MeOH, A.R., Beijing Tong-guang Industry of Fine Chemicals Company), dichloromethane (CH2Cl2, A.R., Beijing Tongguang Industry of Fine Chemicals Company), Toluene (A.R., Sinopharm Chemical Reagent) was dried over calcium hydride for 24 h at room temperature and distilled through a high vacuum line into a solvent storage bottle containing 4 Å molecular sieves. CuBr (A.R., Sinopharm Chemical Reagent) was purified by stirring in acetic acid for 24 h, filtered, repeatedly washed with acetone and stored under an argon atmosphere). The azido-functionalized thiol (N3-SH) was prepared as previously reported by our group. 1 PS-OH with different molecular weights were prepared by anionic polymerization of styrene under high vacuum conditions

3 followed by end-capping with ethylene oxide and quenching with methanol, PDMS-OH was purchased on Gelest Inc. and used without further purification. Instrumentation and Characterizations. Nuclear Magnetic Resonance (NMR) Spectroscopy. All the 1 H and 13 C NMR spectra were obtained using CDCl3 (99%D, J&K Chemicals) as the solvent on Bruker 400 MHz NMR spectrometer. All 1 H NMR spectra were referenced to the peak of residual proton impurities in CDCl3 at δ = 7.27 ppm and all 13 C NMR spectra were referenced to the peak of 13 CDCl3 at δ = ppm. All 29 Si NMR spectra were acquired in a Bruker 500 MHz NMR spectrometer and referenced to tetramethylsilane (TMS) at δ = 0.00 ppm. Fourier-Transform Infrared (FTIR) Spectroscopy. FT-IR spectra of the chemicals were recorded on an Excalibur Series FT-IR spectrometer (DIGILAB, Randolph, MA) by casting sample films on KBr plates or make KBr-sample plates at room temperature. Gel Permeation Chromatography (GPC) GPC analyses for the synthesized polymers were performed on a PL-GPC50 integrated GPC system (Agilent Technologies) equipped with two PLgel 5μm MIXED-C 300*7.5 mm column and a PLgel 10μm Guard, 50*7.5 mm protection column. THF was used as the eluent with a flow rate of 1.00 ml/min at 40 C, and the data acquisitions were performed by a differential refractometer. A series of narrowly distributed polystyrene was used as a standard for molecular weight calculation. Data processing was accomplished using the software on a workstation equipped with this system. Thermal Gravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC) TGA experiments were performed on a TA Q600 analyzer with a heating rate of 10 o C/min. DSC experiments were performed on a TA Q100 analyzer with a heating rate of 10 o C/min.

4 Matrix-assisted Laser Desorption/Ionization Time of Flight (MALDI-TOF) Mass Spectroscopy. All MALDI-TOF mass spectra were obtained on a MALDI TOF/TOF 5800 mass spectrometer (AB Sciex, USA). All spectra were measured in positive reflection mode or linear mode. Trans-2-[3-(4-tert-butylphenyl)- 2-methyl-2-propenyli-dene]-malononitrile (DCTB, >98%, TCI Chemicals) was dissolved in THF (20.0 mg/ml) as the matrix solution. Sodium trifluoroacetate (NaTFA), or silver trifluoroacetate (AgTFA) was dissolved in MeOH/CHCl3 (v/v = 1/3) at 10.0 mg/ml and used as the cationizing agent solution. The matrix and cationizing agent solutions were mixed in a 10/1 (v/v) ratio. The samples were dissolved in CHCl3 at a concentration of 5.0 mg/ml. To prepare the samples, 0.5 μl of the matrix and cationizing agent mixture solution was deposited on the wells of a 384-well ground-steel sample plate and allowed to dry, followed by depositing 0.5 μl of the sample solution on a spot of the dried matrix and cationizing agent, and a second deposition of 0.5 μl of the matrix and cationizing agent mixture solution on top of the dried sample. The sample plate was loaded into the MALDI-TOF mass spectrometer and the spectra were measured in both reflection mode and linear mode. Small Angle X-ray Scattering (SAXS). The X-ray diffraction data were recorded at beamline BL14B1 of the Shanghai Synchrotron Radiation Facility (SSRF) at a wavelength of 1.24 Å or 1.0 Å and beamline 1W2A of the Beijing Synchrotron Radiation Facility (BSRF) a wavelength of 1.54 Å. The sample-to-detector distance was adjusted such as to provide a detecting range for scattering vector q = 4π(sinθ)/λ between 0.01 to 0.30 Å -1. A CCD area detector was used to receive scatter radiation. The scattering vector was calibrated using a silver behenate standard. Equipment adjusting and data processing accorded to standard method. 2 Synthetic Procedures Scheme S1. Synthesis of alkyne-functionalized POSS

5 Synthesis of oom-t8v5(alkyne)3 (Scheme S1). To a 100 ml of round-bottom glass flask equipped with a magnetic stir bar was added 4-pentynoic acid (294 mg, 3.0 mmol), oxalyl chloride (5 ml, 59 mmol) and one drop of DMF. The mixture was stirred at 40 C for 2 h, after which the solution was evaporated by rotary evaporation in ice bath. The left liquid (278 mg, 2.39 mmol, 8 eq.) was dissolved by 5 ml dry DCM, then the solution was slowly added into the ice-cold DCM solution of oom-t8v5(oh)3 (200 mg, 0.39 mmol, 1 eq.) and TEA (400 μl, 8 eq.). Then the mixture was left to stir at 40 C overnight. The product was purified by column chromatography using PE/DCM (v/v = 20/1) as eluent to give oom-t8v5(alkyne)3 as a clear viscous liquid (176 mg). Yield: 65%. 1 H NMR (400 MHz, CDCl3, ppm, δ): (m, 15H), 4.24 (t, J = 8.1 Hz, 6H), 2.51 (m, 12H), 1.98 (m, 3H), 1.21 (m, 6H). 13 C NMR (100 MHz, CDCl3, ppm, δ): , , , , , , , 82.46, 69.06, 69.03, 60.80, 60.76, 33.40, 14.32, 13.07, Si NMR (99 MHz, CDCl3, ppm, δ): , , , , MS (MALDI TOF, m/z): calcd. monoisotopic mass for [C31H24O18Si8Na] + : Da, found Da. Scheme S2. Synthesis of azide-functionalized polystyrene a a. (i) 2-bromoacetic acid, DIPC, DMAP, DCM, 12h; (ii) NaN3, DMF, 24h-48h. Syntheses of PS-N3 (Scheme S2). To a 100 ml of round-bottom glass flask equipped with a magnetic stir bar was added PS-OH (250 mg, 0.12 mmol), 2-bromoacetic acid (27.5mg, 0.20 mmol), catalysis amount of DMAP, and 20 ml dry DCM. The solution was stirred and cooled in ice bath, then 38 μl DIPC (0.24 mmol) dissolved in 2 ml DCM was injected dropwise into the flask. The solution was stirred at room temperature for over 12 h, after that the DCM was removed under reduced pressure. The crude product was purified by column chromatography using toluene as eluent and precipitated in cold methanol, filtered and dried in vacuo to give 230 mg white powder. Yield: 90%. 1 H NMR (400 MHz, CDCl3, ppm, δ): (br, 86H), 3.71-

6 4.02 (br, 2H), (br, 2H), (br, 66H), (br, 6H). 13 C NMR (100 MHz, CDCl3, ppm, δ): , , , , , 64.46, 43.97, 40.44, 31.53, The purified PS-Br (240 mg, 0.11 mmol) was dissolved in 3 ml DMF, then added to a 100 ml of roundbottom glass flask equipped with a magnetic stir bar. After that, 33 mg (0.50 mmol) NaN3 was added and the mixture was stirred at room temperature for 48 h. The reaction mixture was suspended in 20 ml pure water, then 20 ml toluene was added to extract the product. The organic phase was collected and washed with 20 ml pure water for three times. The solvent was removed by rotary evaporation, and the product was purified by dissolving in THF and precipitating in cold methanol. The precipitate was gathered by vacuum filter and dried in vacuum to give a white powder (147mg, Yield: 61% through 2 steps). 1 H NMR (400 MHz, CDCl3, ppm, δ): (100H), (2H), (2H), (62H), (6H). 13 C NMR (100 MHz, CDCl3, ppm, δ): , , , , , 64.46, 43.97, 40.44, 31.53, Synthesis of oom-t8v5(ps19)3: To a mixture of oom-t8v5(alkyne)3 (20 mg, 22 μmol, 1 eq.), PS19-N3 (194 mg, 100 μmol, 4.5 eq.), CuBr (1 mg) in degassed toluene was added 10 μl PMDETA in the glove box. The solution was then stirred at room temperature 24~48 h monitored by SEC. The reaction mixture was applied to column of silica gel, eluted with DCM and DCM/MeOH (v/v = 10/1) successively. The crude product was dissolved in THF and precipitated in cold methanol. The product was collected by vacuum filtration and dried in vacuum to afford oom- T8V5(PS19)3 as a white powder. (149 mg, Yield: 90%) 1 H NMR (400 MHz, CDCl3, ppm, δ): (br, 296H), 6.01 (m, 15H), 4.78 (s, 6H), 4.20 (t, J = 8.1 Hz, 6H), (br, 6H), 3.00 (t, J = 6.5 Hz, 6H), 2.69 (t, J = 7.1 Hz, 6H), (br, 175H), 1.17 (t, J = 8.1 Hz, 6H), (br, 18H). 13 C NMR (125 MHz, CDCl3, ppm, δ): , , , , , , , , , 67.62, 64.53, 60.60, 50.34, 43.88, 40.34, 33.50, 31.48, 29.11, 23.89, 20.86, 13.03, Si NMR (99 MHz, CDCl3, ppm, δ): -

7 68.99, , , , MS (MALDI TOF, m/z): calcd. monoisotopic mass for [M26 Na] + : Da, found Da. FT-IR (KBr) v (cm -1 ): 3359, 3190, 3082, 3060, 3026, 2954, 2922, 2850, 1739, 1658, 1631, 1600, 1492, 1452, 1377, 1217, 1119, 760, 698, 567, 540. Synthesis of oom-t8a5(ps19)3: To a 10mL of Schlenk tube was added oom-t8v5(ps19)3 (170 mg, 24 μmol), N3-SH (70 mg, 0.32 mmol), and Irgacure 2959 (1.0 mg, 4 μmol), the mixture was dissolved in 2 ml of THF. The reaction mixture was thoroughly degassed by the freeze-pump-thaw technique and subsequently initiated under UV 365 nm for 15 min. After that, the excess N3-SH was removed by column chromatography eluted with DCM and DCM/MeOH (v/v = 10/1) successively. The crude product was purified by precipitation in cold methanol, the precipitate was filtered and dried in vacuum to give a white powder (134 mg, Yield: 70%). 1 H NMR (400 MHz, CDCl3, ppm, δ): 7.30 (s,3h), (br, 288H) 4.79 (s, 6H), 4.20 (m, 16H), (br, 6H), 3.26 (t, J = 5.9 Hz, 10H), 2.99 (s, 6H) 2.70 (m, 22H), 2.33 (m, 10H), (br, 190H), 1.15 (m, 10H), 1.03 (m, 6H), (br, 18H). 13 C NMR (125 MHz, CDCl3, ppm, δ): , , , , , , , , 77.28, 77.02, 76.77, 62.94, 60.45, 51.20, 50.37, 40.35, 33.94, 33.47, 31.48, 30.31, 28.54, 26.21, 26.08, 24.39, 20.87, 12.89, Si NMR (99 MHz, CDCl3, ppm, δ): , MS (MALDI TOF, m/z): calcd. average mass for [M52 Ag] + : Da, found Da. FT-IR (KBr) v (cm - 1 ): 3359, 3080, 3060, 3026, 2923, 2852, 2096, 1737, 1600, 1492, 1452, 1377, 1353, 1251, 1178, 1127, 1047, 1031, 758, 700, 542. Scheme S3. Synthesis of alkyne-functionalized polydimethylsiloxane

8 Syntheses of PDMS-alkyne (Scheme S3). To a 10 ml of round-bottom glass flask equipped with a magnetic stir bar was added PDMS-OH (3.0 g, 3.0 mmol), 4-pentynoic acid (0.44 g, 4.5 mmol), catalysis amount of DMAP and 50 ml dry THF. The solution was stirred and cooled in ice bath, then 0.85 ml DIPC (0.68 g, 5.4 mmol) was injected dropwise into the flask. After stirring in room temperature for 24 h, the solvent was removed by rotary evaporation, and the product was purified by column chromatography eluting with DCM/MeOH (v/v = 10/1) to give a clear liquid (2.61g, Yield: 81%). 1 H NMR (400 MHz, CDCl3, ppm, δ): 4.25 (m, 2H), 3.63 (m, 2H), 3.43 (t, J = 6.9 Hz, 2H), 2.59 (t, J = 7.2 Hz, 2H), 2.51 (t, J = 7.0 Hz, 2H), 1.97 (s, 1H), 1.61 (tt, J = 7.6 Hz, 2H), 1.56 (s, 1H), 1.31 (m, 4H), 0.88 (t, J = 6.4 Hz, 3H), 0.53 (m, 4H), 0.07 (m, 92H). 13 C NMR (125 MHz, CDCl3, ppm, δ): , 82.40, 74.14, 68.99, 68.45, 63.94, 33.31, 26.34, 25.46, 23.38, 17.96, 14.34, 14.12, 13.77, 1.15, Si NMR (99 MHz, CDCl3, ppm, δ): 7.64, , , , , Characterization of commercially available PDMS-OH. 1 H NMR (400 MHz, CDCl3, ppm, δ): 3.73 (m, 2H), 3.54 (m, 2H), 3.44 (t, J = 7.0 Hz, 2H), 2.00(s, 1H), 1.60 (m, 4H), 1.31 (m, 4H), 0.88 (t, J = 6.9 Hz, 3H), 0.54 (m, 4H), 0.07 (m, 79H). 13 C NMR (125 MHz, CDCl3, ppm, δ): 73.88, 71.48, 61.72, 26.19, 25.28, 23.26, 17.79, 14.00, 13.62, 0.99, 0.88, Si NMR (99 MHz, CDCl3, ppm, δ): 7.63, , , , , Synthesis of oom-t8(pdms15)5(ps19)3. To a mixture of oom-t8a5(ps19)3 (100 mg, 14 μmol), PDMS15- Alkyne (115.5 mg, 105 μmol), CuBr (~1 mg) in degassed toluene was added 10 μl PMDETA in the glove box. The solution was then stirred at room temperature for 24 h. The reaction mixture was applied to column of silica gel, eluted with DCM and DCM/MeOH (v/v = 10/1) successively. Then the crude product was purified by precipitation in methanol/water (v/v = 10/1) to give the oom-t8(pdms15)5(ps19)3 as a white powder (140 mg). Yield: ~79 %. 1 H NMR (400 MHz, CDCl3, ppm, δ): 7.35, 7.31, (br, 296H) 4.80, 4.28, 4.21, (br, 6H), 3.62, 3.42, 3.03, 2.74, 2.64, 2.31, (br, 230H), 1.15, 1.03, 0.89, 0.80,

9 0.55, 0.08 (m, 452H). 13 C NMR (125 MHz, CDCl3, ppm, δ): , , , , , , , , , , , 74.19, 68.43, 63.79, 62.95, 50.37, 49.97, 40.36, 33.79, 33.56, 30.29, 30.02, 26.36, 26.09, 26.01, 25.44, 24.20, 23.34, 20.89, 17.95, 14.06, 13.80, 12.90, 1.17, 1.05, 0.18, Si NMR (99 MHz, CDCl3, ppm, δ): 7.64, , , , , , , FT-IR (KBr) v (cm -1 ): 3450, 3082, 3059, 3026, 2962, 2925, 2854, 1737, 1602, 1492, 1450, 1412, 1384, 1261, 1182, 1097, 1026, 802, 700, 621, 542. Calculations Calculation of the number-average molecular weight using 1 H NMR. For PS-N3, the calculation of molecular weight was based on the integration ratio in 1 H NMR spectra between the peak of δ 7.36 (APhenyl) and that of δ ppm (ACH2O) using the following equations where N is the number of repeating units of PS-N3, Mn, PS is the MW of PS-N3, Msty is the MW of the styrene monomer (104 Da) and M0 is the MW of the rest of the molecule (185 Da): M n,ps = M 0 + N M sty Eq. S1 N = A Phenyl/5 A CH2O /2 Eq. S2 For PDMS-Alkyne, the calculation of molecular weight was based on the integration ratio in 1 H NMR spectra between the peak of δ ppm (Adimethyl) and of δ 4.26 ppm (ACH2O) using the following equations where N1 is the number of repeating units of PDMS-Alkyne, Mn, PDMS is the MW of PDMS-Alkyne, Mdms is the MW of the dimethylsiloxane monomer (74 Da) and M1 is the MW of the rest of the molecule (298 Da): M n,pdms Alkyne = M 1 + N 1 M dms Eq. S3 N 1 = A dimethyl /6 A CH2O /2 Eq. S4

10 For oom-t8v5(ps)3, the calculation of molecular weight was based on the integration ratio in 1 H NMR spectra between the peak of δ 7.36 ppm (APhenyl), which is the phenyl group of PS, and the characteristic peak of the POSS cage (15H) at δ 6.14 ppm (AVinyl) using the following equations where N2 is the number of styrene repeating units of oom-t8v5(ps)3, Msty is the MW of the styrene monomer (104 Da) and M2 is the MW of the rest of the molecule (1483 Da): M n,oom T8 V 5 (PS) 3 = M 2 + N 2 M sty Eq. S5 N 2 = A Phenyl /5 A Vinyl /15 Eq. S6 For oom-t8a5(ps)3, the calculation of molecular weight was based on the value of oom-t8v5(ps)3, M3 is the MW of five N3-SH of the molecule (1085 Da): M n,oom T8 A 5 (PS) 3 = M 3 + M n,oom T8 V 5 (PS) 3 Eq. S7 For Mn,PDMS, of oom-t8pdms5(ps)3, the calculation of molecular weight was based on the integration ratio in 1 H NMR spectra between the peak of δ 7.36 ppm (APhenyl), which is the phenyl group of PS, and the characteristic peak of PDMS at δ (Amethyl), using the following equation: M n,pdms = A methyl 6 M dms Eq. S8 where the values of A methyl are based on the values of A Phenyl which are set identical as in the calculation of oom-t8v5(ps)3. For oom-t8pdms5(ps)3, the molecular weight is simply the sum up of Mn, oom-t8a5(ps)3 and Mn,PDMS. For the ratio between PS arm number and PDMS arm number (n in Table 2), the calculation was based on the integration ratio in 1 H NMR spectra between the peak of δ 7.36 ppm (APhenyl), which is the phenyl group of PS, and the characteristic peak of PDMS at δ (Amethyl) using the following equations where n1 is the arm number of PS, n2 is the arm number of PDMS:

11 n = n 1 n 2 = A Phenyl /5N A methyl /6N 1 Eq. S9 Finally, the Rg values were obtained from a fitted relationship between experimentally measured Rg and molecular weight of PS as depicted in Eq. (S10): 3 logr g = logm n,ps Eq. S10 The experimental Rg values of polystyrene are measured using light scattering with samples that are prepared via anionic polymerization and possess narrow polydispersity with molecular weights ranging from 3.0 kda to 20.0 kda. The experiment was performed with PS in the mixed chlorobenzene/octane solvent. The Rg values were estimated from the hydrodynamic radius in these solutions. The mixed solvent is slightly better than the θ condition for PS homopolymers. The relationship between Rg and Mn were then fitted to give the above equation, which gives a good estimation of the Rg of PS chains in this MW range, especially for lower MWs.

12 Figure S1. 1 H NMR spectra of oom-t8v5(oh)3 (A) and oom-t8v5(alkyne)3 (B) and the corresponding assignment. Asterisks are resonances from residual CDCl3 water and TMS.

13 Figure S2. 13 C NMR spectrum of oom-t8v5(alkyne)3. Asterisks are resonances from residual CDCl3.

14 Figure S3. MALDI-TOF MS spectrum of oom-t8v5(alkyne)3.

15 Figure S4. 1 H NMR spectra of PS19-Br (A), PS19-N3 (B) and the corresponding assignment. Asterisks are resonances from residual CDCl3 and TMS.

16 Figure S5. 1 H NMR spectra of PDMS-OH (A) and PDMS-Alkyne (B) and the corresponding assignment. Asterisks are resonances from residual acetone and water.

17 Figure S6. 13 C NMR spectra of PDMS-OH (A) and PDMS-alkyne (B). Asterisks are resonances from residual CDCl3.

18 Figure S7. 29 Si NMR spectra of PDMS-OH (A), PDMS-alkyne (B). Asterisks are resonances from TMS.

19 Figure S8. 13 C NMR spectra of oom-t8v5(ps19)3 (A), oom-t8a5(ps19)3 (B) and oom-t8(pdms15)5(ps19)3 (C). Asterisks are resonances from residual CDCl3 and TMS.

20 Figure S9. MALDI-TOF MS spectrum of oom-t8a5(ps19)3.

21 Figure S10. FT-IR spectra of oom-t8v5(ps19)3, oom-t8a5(ps19)3 and oom-t8(pdms15)5(ps19)3.

22 Figure S11. TGA curves showing the high thermal stability of Janus star polymers.

23 Figure S12. DSC thermograms of the Janus star polymers: (A) oom-t8(pdms15)5(ps11)3, (B) oom- T8(PDMS15)5(PS19)3 and (C) oom-t8(pdms15)5(ps74)3.

24 References (1) Shao, Y.; Yin, H.; Wang, X.-M.; Han, S.-Y.; Yan, X.; Xu, J.; He, J.; Ni, P.; Zhang, W.-B. Mixed [2 : 6] Hetero-Arm Star Polymers Based on Janus POSS with Precisely Defined Arm Distribution. Polym. Chem. 2016, 7, (2) Zeng, J.; Bian, F.; Wang, J.; Li, X.; Wang, Y.; Tian, F.; Zhou, P. Performance on absolute scattering intensity calibration and protein molecular weight determination at BL16B1, a dedicated SAXS beamline at SSRF. J. Synchrotron. Radiat. 2017, 24, (3) Zheng, J. X.; Xiong, H.; Chen, W. Y.; Lee, K.; Van Horn, R. M.; Quirk, R. P.; Lotz, B.; Thomas, E. L.; Shi, A. C.; Cheng, S. Z. D. Onsets of Tethered Chain Overcrowding and Highly Stretched Brush Regime via Crystalline-Amorphous Diblock Copolymers. Macromolecules 2006, 39,