Table 9 The Surface-active parameters of Betaine, DES (betaine + urea), IL (betaine octyl ester chloride) in various molality concentrations of aqueous Gabapentin solutions (from 0.0000 to 0.0500\(mol \cdot k{g^{ - 1}}\)) at 298 K and ambient pressure.
CMC \(\:\left(\text{m}\text{o}\text{l}\:{\text{k}\text{g}}^{-1}\right)\) | \(\gamma\) (mN m−1) | \(\:\varPi\:\) (mN m−1) | 103\(\:\times\:{\varGamma\:}_{max}\) \(\:\left(\text{m}\text{o}\text{l}\:{\text{m}}^{-2}\right)\) | \(\:{A}_{min}\) (Å2) | \(\:{\varDelta\:G}_{mic}\) (kJ mol−1) | \(\:{\varDelta\:\text{G}}_{\text{a}\text{d}\text{s}}\) (kJ mol−1) |
|---|---|---|---|---|---|---|
Betaine + water | ||||||
0.0148 | 56.3 | 9.1 | 2.039 | 0.081 | -23.089 | -18.627 |
15.7 | 1.858 | 0.089 | -21.369 | -12.917 | ||
19.6 | 1.705 | 0.097 | -20.372 | -8.878 | ||
21.7 | 1.575 | 0.105 | -19.657 | -5.880 | ||
23.2 | 1.461 | 0.114 | -19.100 | -3.222 | ||
24.8 | 1.363 | 0.122 | -18.657 | -0.459 | ||
Betaine in 0.0099 mol kg−1 concentration of aqueous gabapentin solution | ||||||
0.0100 | 48.4 | 10.0 | -0.347 | -0.478 | -26.916 | -55.716 |
12.4 | 1.109 | 0.15 | -24.899 | -13.717 | ||
16.5 | 1.734 | 0.096 | -23.136 | -13.618 | ||
20.8 | 1.815 | 0.092 | -22.099 | -10.638 | ||
23.6 | 1.748 | 0.095 | -21.382 | -7.881 | ||
26.9 | 1.486 | 0.112 | -20.383 | -2.286 | ||
28.4 | 1.165 | 0.143 | -19.638 | 4.742 | ||
30.1 | 0.871 | 0.191 | -19.111 | 15.433 | ||
30.2 | 0.548 | 0.303 | -18.618 | 36.527 | ||
Betaine in 0.0299 mol kg−1 concentration of aqueous gabapentin solution | ||||||
0.0075 | 45.4 | 16.0 | -0.163 | -1.022 | -27.101 | -125.56 |
18.6 | 1.193 | 0.139 | -24.849 | -9.257 | ||
23.3 | 1.652 | 0.100 | -23.147 | -9.047 | ||
27.5 | 1.692 | 0.098 | -22.128 | -5.873 | ||
29.5 | 1.605 | 0.103 | -21.362 | -2.9801 | ||
32.4 | 1.367 | 0.121 | -20.437 | 3.265 | ||
34.2 | 1.066 | 0.156 | -19.684 | 12.4 | ||
34.7 | 0.783 | 0.212 | -19.130 | 25.186 | ||
36.2 | 0.513 | 0.324 | -18.677 | 51.857 | ||
Betaine in 0.0498 mol.kg−1 concentration of aqueous gabapentin solution | ||||||
0.0065 | 40.7 | 22.7 | 0.530 | 0.313 | -21.228 | 21.571 |
26.4 | 1.159 | 0.143 | -24.918 | -2.142 | ||
31.2 | 1.364 | 0.122 | -23.155 | -0.280 | ||
33.9 | 1.356 | 0.122 | -22.118 | 2.875 | ||
35.6 | 1.296 | 0.128 | -21.402 | 6.078 | ||
38.2 | 1.132 | 0.147 | -20.402 | 13.332 | ||
39.7 | 0.955 | 0.174 | -19.657 | 21.893 | ||
41.0 | 0.799 | 0.208 | -19.130 | 32.180 | ||
41.3 | 0.631 | 0.263 | -18.637 | 46.823 | ||
DES (betaine-urea 1:2) + water | ||||||
0.0150 | 66.9 | 13.0 | -0.010 | -16.116 | -27.077 | -1288.703 |
8.6 | 1.976 | 0.084 | -24.801 | -20.450 | ||
7.9 | 1.831 | 0.091 | -23.087 | -18.772 | ||
6.9 | 1.570 | 0.106 | -22.040 | -17.644 | ||
5.6 | 1.567 | 0.106 | -21.368 | -17.795 | ||
5.1 | 2.147 | 0.077 | -20.372 | -17.997 | ||
6.2 | 3.251 | 0.051 | -19.660 | -17.753 | ||
7.0 | 4.689 | 0.035 | -19.100 | -17.608 | ||
10.9 | 6.364 | 0.026 | -18.634 | -16.921 | ||
DES (betaine-urea 1:2) in 0.0103 mol.kg−1 concentration of aqueous gabapentin solution | ||||||
0.0100 | 53.4 | 26.1 | 0.008 | 19.799 | -27.102 | 3084.853 |
21.6 | 0.055 | 2.992 | -24.825 | 364.368 | ||
19.4 | 0.328 | 0.506 | -23.111 | 36.035 | ||
18.9 | 0.443 | 0.375 | -22.112 | 20.535 | ||
18.6 | 0.530 | 0.313 | -21.375 | 13.692 | ||
18.3 | 0.733 | 0.227 | -20.370 | 4.608 | ||
19.4 | 1.012 | 0.164 | -19.660 | -0.484 | ||
19.9 | 1.363 | 0.122 | -19.105 | -4.502 | ||
21.4 | 1.781 | 0.093 | -18.64 | -6.624 | ||
DES (betaine-urea 1:2) in 0.0297 mol kg−1 concentration of aqueous gabapentin solution | ||||||
0.0075 | 49.8 | 28.8 | 4.014 | 0.041 | -27.092 | -19.917 |
24.5 | 2.539 | 0.065 | -24.823 | -15.173 | ||
23.0 | 1.698 | 0.098 | -23.117 | -9.570 | ||
22.2 | 1.318 | 0.126 | -22.129 | -5.281 | ||
21.6 | 1.086 | 0.153 | -21.402 | -1.511 | ||
22.8 | 0.828 | 0.201 | -20.364 | 7.174 | ||
21.3 | 0.709 | 0.234 | -19.712 | 10.313 | ||
23.0 | 0.633 | 0.262 | -19.139 | 17.199 | ||
23.2 | 0.592 | 0.281 | -18.693 | 20.529 | ||
DES (betaine-urea 1:2) in 0.0501 mol kg−1 concentration of aqueous gabapentin solution | ||||||
0.0050 | 46.2 | 31.9 | 1.654 | 0.100 | -27.104 | -7.812 |
27.8 | -1.109 | -0.150 | -24.807 | -49.881 | ||
25.0 | -0.065 | -2.560 | -23.07 | -408.452 | ||
25.0 | 0.170 | 0.978 | -22.114 | 125.137 | ||
25.1 | 0.118 | 1.413 | -21.379 | 192.134 | ||
26.0 | 0.008 | 20.728 | -20.362 | 3225.001 | ||
25.7 | 0.249 | 0.668 | -19.682 | 83.647 | ||
26.4 | 0.947 | 0.175 | -19.099 | 8.766 | ||
28.8 | 1.989 | 0.083 | -18.643 | -4.162 | ||
IL (betaine octyl ester chloride) + water | ||||||
0.0125 | 28.4 | 27.0 | 0.002 | 91.804 | -27.077 | 14899.651 |
32.4 | 0.616 | 0.269 | -24.801 | 27.761 | ||
38.7 | 1.064 | 0.156 | -23.087 | 13.29 | ||
43.4 | 0.912 | 0.182 | -22.04 | 25.531 | ||
45.6 | 0.660 | 0.252 | -21.368 | 47.742 | ||
48.1 | 0.269 | 0.618 | -20.372 | 158.748 | ||
50.4 | 0.136 | 1.219 | -19.660 | 350.437 | ||
51.6 | 0.247 | 0.673 | -19.100 | 190.116 | ||
52.7 | 0.558 | 0.297 | -18.634 | 75.778 | ||
IL(betaine octyl ester chloride) in 0.0105 mol kg−1 concentration of aqueous gabapentin solution | ||||||
0.0125 | 22.6 | 29.5 | 0.034 | 4.889 | -27.174 | 841.402 |
35.6 | 0.193 | 0.860 | -24.854 | 159.45 | ||
42.2 | 0.445 | 0.373 | -23.087 | 71.740 | ||
45.9 | 0.356 | 0.467 | -22.095 | 106.944 | ||
48.7 | 0.177 | 0.938 | -21.332 | 253.853 | ||
51.3 | -0.058 | -2.866 | -20.413 | -905.853 | ||
52.8 | -0.190 | -0.875 | -19.654 | -297.992 | ||
54.0 | -0.176 | -0.945 | -19.102 | -326.267 | ||
55.0 | -0.057 | -2.899 | -18.661 | -978.869 | ||
IL(betaine octyl ester chloride) in 0.0304 mol kg−1 concentration of aqueous gabapentin solution | ||||||
0.0094 | 21.9 | 33.6 | 2.727 | 0.061 | -26.983 | -14.664 |
40.7 | 0.905 | 0.183 | -24.753 | 20.201 | ||
46.6 | 1.182 | 0.140 | -23.079 | 16.331 | ||
49.6 | 0.901 | 0.184 | -22.143 | 32.925 | ||
51.6 | 0.692 | 0.240 | -21.306 | 53.236 | ||
53.2 | 0.588 | 0.282 | -20.436 | 70.005 | ||
54.6 | 0.595 | 0.279 | -19.711 | 72.109 | ||
55.5 | 0.468 | 0.355 | -19.061 | 99.510 | ||
55.9 | 0.101 | 1.638 | -18.66 | 532.678 | ||
IL(betaine octyl ester chloride) in 0.0499 mol kg−1 concentration of aqueous gabapentin solution | ||||||
0.0073 | 20.7 | 37.0 | 0.801 | 0.207 | -27.079 | 19.114 |
44.9 | 1.243 | 0.134 | -24.807 | 11.303 | ||
50.7 | 0.905 | 0.183 | -23.089 | 32.909 | ||
52.7 | 0.679 | 0.245 | -22.084 | 55.511 | ||
54.3 | 0.545 | 0.305 | -21.371 | 78.244 | ||
55.8 | 0.407 | 0.408 | -20.367 | 116.738 | ||
56.4 | 0.339 | 0.490 | -19.654 | 146.786 | ||
56.9 | 0.293 | 0.567 | -19.101 | 175.163 | ||
57.4 | 0.252 | 0.660 | -18.649 | 209.362 | ||
