Electronic Supplementary Material

Synthesis and Self-assembly Properties of Well-defined Four-arm Star Poly(ε-Caprolactone)-b-Poly(N-Vinylpyrrolidone) Amphiphilic Block Copolymers

Avnish Kumar Mishra,1 K. Ramesh,1,2 Tapas Paira,3 Divesh N. Srivastava,4 Tarun Kumar Mandal,3 Nira Mishra,2 Biswajit Ray1*

1Department of Chemistry, Faculty of Science, Banaras Hindu University, Varanasi – 221005, India

2School of Biomedical Engineering, Indian Institute of Technology - Banaras Hindu University, Varanasi – 221005, India

3Polymer Science Unit, Indian Association for the Cultivation of Science, Jadavpur, Kolkata-700 032, India

4Central Salt &Marine Chemicals Research Institute (CSIR), G. B. Marg, Bhavnagar – 364021, Gujarat, India

Synthesis of the four-arm star block copolymer S-(PCL21-b-PNVP28)4 (run 2, Table 1)

This block copolymer was prepared as mentioned in the previous section for run1, Table 1 using 0.4 gm [5.23 × 10-5 mol, calculated on the basis of molecular weight (7,654 g mol-1) obtained from 1H NMR] S-(PCL21-X)4, 1.35 mL (1.41 g, 1.26 × 10-2 mol) NVP, 10.4 mg (6.35 x 10-5 mol) AIBN, and 4 mL THF. Observed monomer conversion by 1H NMR = 48%.

1H NMR (300 MHz, CDCl3): δ (ppm) = 1.3-2.5 (m, 2Hb+4Hc+2Hd+3Hf +3Hi+2Hk+

2Hl+2Ho), 2.9-4.5 (m, 2Ha+2Hj+1Hp).

Mn (NMR) = 19,496 g mol-1, Mn (GPC) = 21,900 g mol-1, Mw/ Mn = 1.25.

Synthesis of the block four-arm star copolymer S-(PCL21-b-PNVP37)4 (run 3, Table 1)

This block copolymer was prepared as mentioned in the previous section for run1, Table 1 using 0.4 gm [5.23 × 10-5 mol, calculated on the basis of molecular weight (7,654 g mol-1) obtained from 1H NMR] S-(PCL21-X)4, 2.0 mL (2.11 g, 1.9 × 10-2 mol) NVP, 10.4 mg (6.35 x 10-5 mol) AIBN, and 4.5 mL THF. Observed monomer conversion by 1H NMR = 38 %.

1H NMR (300 MHz, CDCl3): δ (ppm) = 1.3-2.5 (m, 2Hb+4Hc+2Hd+3Hf +3Hi+2Hk+

2Hl+2Ho), 2.9-4.5 (m, 2Ha+2Hj+1Hp).

Mn (NMR) = 26,563 g mol-1, Mn (GPC) = 25,900 g mol-1, Mw/ Mn = 1.29.

Synthesis of the four-arm star block copolymer S-(PCL21-b-PNVP46)4 (run 4, Table 1)

This block copolymer was prepared as mentioned in the previous section for run1, Table 1 using 0.4 gm [5.23 × 10-5 mol, calculated on the basis of molecular weight (7,654 g mol-1) obtained from 1H NMR] S-(PCL21-X)4, 2.82 mL (2.82 g, 2.5 × 10-2 mol) NVP, 10.4 mg (6.35 x 10-5 mol) AIBN, and 5 mL THF. Observed monomer conversion by 1H NMR = 40 %.

1H NMR (300 MHz, CDCl3): [Figure 3(a)] δ (ppm) = 1.3-2.5 (m, 2Hb+4Hc+2Hd+3Hf

+3Hi+2Hk+2Hl+2Ho), 2.9-4.5 (m, 2Ha+2Hj+1Hp).

Mn (NMR) = 31,847 g mol-1, Mn (GPC) = 30,000 g mol-1, Mw/ Mn = 1.21.

Figure S1.semilogarithmic plot of the fluorescence excitation intensity ratio (I337.07/I333.07) of pyrene (6 ´ 10-7 M) (monitored at lem = 394 nm) vs. the concentration of S-(PCL21-b-PNVP15)4 (run 1, Table 4) star block block copolymer in water.

Figure S2.semilogarithmic plot of the fluorescence excitation intensity ratio (I337.07/I333.07) of pyrene (6 ´ 10-7 M) (monitored at lem = 394 nm) vs. the concentration of S-(PCL21-b-PNVP28)4 (run 2, Table 4) star block block copolymer in water.

Figure S3.semilogarithmic plot of the fluorescence excitation intensity ratio (I337.07/I333.07) of pyrene (6 ´ 10-7 M) (monitored at lem = 394 nm) vs. the concentration of S-(PCL21-b-PNVP37)4 (run 3, Table 4) star block block copolymer in water.


• Bimodal Particle size distribution was observed: 74.41% population has mean diameter of 87 nm and rest has mean diameter of 23.85 nm.

Figure S4. Particle size (NNLS particle diameter) distribution of micelles formed from the S-(PCL21-b-PNVP28)4 block copolymer solution in water at 0.5 mg/ml concentration and measured at 90o scattering angle DLS measurement.


• Bimodal Particle size distribution was observed: 78.22 % population has mean diameter of 50.56 nm and rest has mean diameter of 20.54 nm.

Figure S6. Particle size (NNLS particle diameter) distribution of micelles formed from the S-(PCL21-b-PNVP46)4 block copolymer solution in water at 0.5 mg/ml concentration and measured at 90o scattering angle DLS measurement.