44. Shams Es-haghi S, Mayfield M, Weiss RA (2018) Effect of freeze/thaw process on mechanical
behavior of double-network hydrogels in finite tensile deformation. Macromolecules
51:1052–1057
45. Zhu XK, Joyce JA (2012) Review of fracture toughness (G, K, J, CTOD, CTOA) testing and
standardization. Eng Fract Mech 85:1–46
46. Long R, Hui CY (2016) Fracture toughness of hydrogels: measurement and interpretation. Soft
Matter 12:8069–8086
47. Rivlin RS, Thomas AG (1953) Rupture of rubber. I. Characteristic energy for tearing. J Polym
Sci 10:291–318
48. Sun JY, Zhao X, Illeperuma WRK, Chaudhuri O, Oh KHO, Mooney DJ, Vlassak JJ, Suo Z
(2012) Highly stretchable and tough hydrogels. Nature 489:133–136
49. Persson BN, Albohr O, Heinrich G, Ureba H (2005) Crack propagation in rubber-like
materials. J Phys Condens Matter 17:R1071–R1142
50. Wang T, Zheng S, Sun W, Liu X, Fu S, Tong Z (2014) Notch insensitive and self-healing
PNipamÀPAMÀclay nanocomposite hydrogels. Soft Matter 10:3506–3512
51. Guo H, Sanson N, Hourdet D, Marcellan A (2016) Thermoresponsive toughening with crack
bifurcation in phase-separated hydrogels under isochoric conditions. Adv Mater
28:5857–5864
52. Guo H, Mussault C, Brûlet C, Marcellan A, Hourdet D, Sanson NA (2016) Thermoresponsive
toughening in LCST-type hydrogels with opposite topology: from structure to fracture properties. Macromolecules 49:4295–4306
53. Guo H, Sanson N, Hourdet D, Marcellan A, Sanson N, Hourdet D, Marcellan A (2016)
Thermoresponsive toughening with crack bifurcation in phase-separated hydrogels under
isochoric conditions. Adv Mater 28:5857–5864
54. Li J, Illeperuma RK, Suo Z, Vlassak JJ (2014) Hybrid hydrogels with extremely high stiffness
and toughness. ACS Macro Lett 3:520–523
55. Zhang M, Wang R, Shi Z, Huang X, Zhao W, Zhao C (2017) Multi-responsive, tough and
reversible hydrogels with tunable swelling property. J Hazard Mater 322:499–507
56. Zhao X (2014) Multi-scale multi-mechanism design of tough hydrogels: building dissipation
into stretchy networks. Soft Matter 10:672–687
57. Xin H, Brown HR, Naficy S, Spinks GM (2015) Time dependent mechanical properties of
tough ionic-covalent hybrid hydrogels. Polymer 65:253–261
58. Li J, Illeperuma WRK, Suo Z, Vlassak JJ (2014) Hydrogels with extremely high stiffness and
toughness. ACS Macro Lett 3:520–523
59. Sun TL, Kurokawa T, Kuroda S, Ihsan AB, Akasaki T, Sato K, Haque MA, Nakajima T, Gong
JP (2013) Physical hydrogels composed of polyampholytes demonstrate high toughness and
viscoelasticity. Nat Mater 12:932–937
60. Zhu F, Lin XY, Wu ZL, Cheng L, Yin J, Song Y, Qian J, Zheng Q (2016) Crack blunting and
advancing behaviors of tough and self-healing polyampholyte hydrogel. Polymer 95:9–17
61. Zheng SY, Ding H, Qian J, Yin J, Wu ZL, Song Y, Zheng Q (2016) Metal-coordination
complexes mediated physical hydrogels with high toughness, stickÀslip tearing behavior, and
good processability. Macromolecules 49:9637–9646
62. Cooper W (1958) Copolymers of butadiene and unsaturated acids: crosslinking by metal
oxides. J Polym Sci 28:195–206
63. Li J, Suo Z, Vlassak J (2014) Stiff, strong, and tough hydrogels with good chemical stability. J
Mater Chem B 2:6708–6713
64. Webber RE, Creton C, Brown HR, Gong JP (2007) Large strain hysteresis and Mullins effect
of tough double-network hydrotgels. Macromolecules 40:2919–2927
65. Gong JP (2010) Why are double network hydrogels so tough? Soft Matter 6:2583–2590
66. Mullins L, Tobiin NR (1965) Stress softening in rubber vulcanizates. Part I. Use of a strain
amplification factor to describe the elastic behavior of filler-reinforced vulcanized rubber. J
Appl Polym Sci 9:2993–3009
Hydrophobically Associating Hydrogels with Microphase-Separated Morphologies
207
behavior of double-network hydrogels in finite tensile deformation. Macromolecules
51:1052–1057
45. Zhu XK, Joyce JA (2012) Review of fracture toughness (G, K, J, CTOD, CTOA) testing and
standardization. Eng Fract Mech 85:1–46
46. Long R, Hui CY (2016) Fracture toughness of hydrogels: measurement and interpretation. Soft
Matter 12:8069–8086
47. Rivlin RS, Thomas AG (1953) Rupture of rubber. I. Characteristic energy for tearing. J Polym
Sci 10:291–318
48. Sun JY, Zhao X, Illeperuma WRK, Chaudhuri O, Oh KHO, Mooney DJ, Vlassak JJ, Suo Z
(2012) Highly stretchable and tough hydrogels. Nature 489:133–136
49. Persson BN, Albohr O, Heinrich G, Ureba H (2005) Crack propagation in rubber-like
materials. J Phys Condens Matter 17:R1071–R1142
50. Wang T, Zheng S, Sun W, Liu X, Fu S, Tong Z (2014) Notch insensitive and self-healing
PNipamÀPAMÀclay nanocomposite hydrogels. Soft Matter 10:3506–3512
51. Guo H, Sanson N, Hourdet D, Marcellan A (2016) Thermoresponsive toughening with crack
bifurcation in phase-separated hydrogels under isochoric conditions. Adv Mater
28:5857–5864
52. Guo H, Mussault C, Brûlet C, Marcellan A, Hourdet D, Sanson NA (2016) Thermoresponsive
toughening in LCST-type hydrogels with opposite topology: from structure to fracture properties. Macromolecules 49:4295–4306
53. Guo H, Sanson N, Hourdet D, Marcellan A, Sanson N, Hourdet D, Marcellan A (2016)
Thermoresponsive toughening with crack bifurcation in phase-separated hydrogels under
isochoric conditions. Adv Mater 28:5857–5864
54. Li J, Illeperuma RK, Suo Z, Vlassak JJ (2014) Hybrid hydrogels with extremely high stiffness
and toughness. ACS Macro Lett 3:520–523
55. Zhang M, Wang R, Shi Z, Huang X, Zhao W, Zhao C (2017) Multi-responsive, tough and
reversible hydrogels with tunable swelling property. J Hazard Mater 322:499–507
56. Zhao X (2014) Multi-scale multi-mechanism design of tough hydrogels: building dissipation
into stretchy networks. Soft Matter 10:672–687
57. Xin H, Brown HR, Naficy S, Spinks GM (2015) Time dependent mechanical properties of
tough ionic-covalent hybrid hydrogels. Polymer 65:253–261
58. Li J, Illeperuma WRK, Suo Z, Vlassak JJ (2014) Hydrogels with extremely high stiffness and
toughness. ACS Macro Lett 3:520–523
59. Sun TL, Kurokawa T, Kuroda S, Ihsan AB, Akasaki T, Sato K, Haque MA, Nakajima T, Gong
JP (2013) Physical hydrogels composed of polyampholytes demonstrate high toughness and
viscoelasticity. Nat Mater 12:932–937
60. Zhu F, Lin XY, Wu ZL, Cheng L, Yin J, Song Y, Qian J, Zheng Q (2016) Crack blunting and
advancing behaviors of tough and self-healing polyampholyte hydrogel. Polymer 95:9–17
61. Zheng SY, Ding H, Qian J, Yin J, Wu ZL, Song Y, Zheng Q (2016) Metal-coordination
complexes mediated physical hydrogels with high toughness, stickÀslip tearing behavior, and
good processability. Macromolecules 49:9637–9646
62. Cooper W (1958) Copolymers of butadiene and unsaturated acids: crosslinking by metal
oxides. J Polym Sci 28:195–206
63. Li J, Suo Z, Vlassak J (2014) Stiff, strong, and tough hydrogels with good chemical stability. J
Mater Chem B 2:6708–6713
64. Webber RE, Creton C, Brown HR, Gong JP (2007) Large strain hysteresis and Mullins effect
of tough double-network hydrotgels. Macromolecules 40:2919–2927
65. Gong JP (2010) Why are double network hydrogels so tough? Soft Matter 6:2583–2590
66. Mullins L, Tobiin NR (1965) Stress softening in rubber vulcanizates. Part I. Use of a strain
amplification factor to describe the elastic behavior of filler-reinforced vulcanized rubber. J
Appl Polym Sci 9:2993–3009
Hydrophobically Associating Hydrogels with Microphase-Separated Morphologies
207