Hydrogel-based quasi-solid-state electrolytes(Q-SSEs) swollen with electrolyte solutions are important components in stretchable supercapacitors and other wearable devices. This work fabricates a supertough, fatigue-r...Hydrogel-based quasi-solid-state electrolytes(Q-SSEs) swollen with electrolyte solutions are important components in stretchable supercapacitors and other wearable devices. This work fabricates a supertough, fatigue-resistant, and alkali-resistant multi-bond network(MBN) hydrogel aiming to be an alkaline Q-SSE. To synthesize the hydrogel, a 2-ureido-4[1H]-pyrimidone(UPy) motif is introduced into a poly(acrylic acid) polymer chain. The obtained MBN hydrogels with 75 wt% water content exhibit tensile strength as high as 2.47 MPa, which is enabled by the large energy dissipation ability originated from the dissociation of UPy dimers due to their high bond association energy. Owing to the high dimerization constant of UPy motifs, the dissociated UPy motifs are able to partially re-associate soon after being released from external forces, resulting in excellent fatigue-resistance. More importantly, the MBN hydrogels exhibit excellent alkali-resistance ability. The UPy Gel-10 swollen with 1 mol/L KOH display a tensile strength as high as ~1.0 MPa with elongation at break of ~550%. At the same time, they show ionic conductivity of ~17 m S/cm, which do not decline even when the hydrogels are stretched to 500% strain.The excellent mechanical property and ionic conductivity of the present hydrogels demonstrate potential application as a stretchable alkaline Q-SSE.展开更多
Multi-bond network(MBN) hydrogels contain hierarchical dynamic bonds with different bond association energy as energy dissipation units,enabling super-tough mechanical properties.In this work,we copolymerize a protona...Multi-bond network(MBN) hydrogels contain hierarchical dynamic bonds with different bond association energy as energy dissipation units,enabling super-tough mechanical properties.In this work,we copolymerize a protonated 2-ureido-4[1 H]-pyrimidone(UPy)-contained monomer with acrylic acid in HCl solution.After removing excess HCl,UPy motifs are deprotonated and from dimers,thus generating an UPy-contained MBN hydrogel.The obtained MBN hydrogels(75 wt% watercontent) exhibit super-tough mechanical properties(0.39 MPa to 2.51 MPa tensile strength),with tremendous amount of energy(1.68 MJ/m^(3) to 11.1 MJ/m^(3)) dissipated by the dissociation of UPy dimers.The introduction of ionic bonds can further improve the mechanical properties.Moreover,owing to their dynamic nature,both UPy dimers and ionic bonds can re-associate after being dissociated,resulting in excellent self-recovery ability(around 90% recovery efficiency within only 1 h).The excellent self-recovery ability mainly originates from the re-association of UPy dimers based on the high dimerization constant of UPy motifs.展开更多
Polyvinyl alcohol(PVA)-based hydrogels are widely used in the fields of tissue engineering,biomedicine,and flexible sensors due to their low cost,excellent biocompatibility,and simple gelation methods.Re-peated freeze...Polyvinyl alcohol(PVA)-based hydrogels are widely used in the fields of tissue engineering,biomedicine,and flexible sensors due to their low cost,excellent biocompatibility,and simple gelation methods.Re-peated freeze-thaw cycles are essential for the preparation of such hydrogels.Although this process can enhance the mechanical properties of the hydrogels to a certain extent,it can also result in opacity and limited tensile performance,significantly restricting their application in wearable devices and electronic skin.This study introduced cellulose nanofibers into polyacrylamide(PAM)/PVA double interpenetrat-ing network hydrogel system,achieving the preparation of a multifunctional composite hydrogel with a“triple-network interlock”structure.Under the synergistic effects of multiple networks,multiple hy-drogen bonds,and nano-reinforcement,this composite hydrogel requires only a single freeze-thaw cycle to achieve a tensile strength exceeding 1 MPa,which is significantly higher than that of PVA hydro-gels subjected to multiple freeze-thaw cycles.The PVA-based hydrogel prepared in this work balances tensile strength(1.41 MPa),elongation(1332%),transparency(89.8%),and toughness(6.73 MJ m^(-3)).Ad-ditionally,this composite hydrogel exhibits high sensitivity(GF=8.74),rapid response(108 ms),fatigue resistance,and antibacterial properties,making it a reliable strain sensor over a wide strain range.When encapsulated on human joints,it can monitor body movements in real-time,such as movements of fin-gers,wrists,elbows,and knees,and can be integrated into peripheral circuits to achieve precise real-time control of robotic hands.This work presents a multifunctional composite hydrogel with great potential as a candidate material for tissue engineering,human-machine interaction,and high-performance wearable sensors.展开更多
The multi-bond dissociation dynamics of oxalyl bromide （（BrCO）2） has been investigated by DFT and CIS calculations. Upon the results, conclusion could be drawn that dissociation of C-Br bond of oxalyl bromide at t...The multi-bond dissociation dynamics of oxalyl bromide （（BrCO）2） has been investigated by DFT and CIS calculations. Upon the results, conclusion could be drawn that dissociation of C-Br bond of oxalyl bromide at the ground state （So） is of barfierless. After the absorption of a photon, （BrCO）2 is excited to the first excited state and one of its C-Br bonds is broken to yield Br ·＊ and BrCOCO· ＊ free radicals. In addition, BrCOCO · ＊ with high energy is apt to release energy, and ultimately, turns into BrCOCO ·of the ground state. The energy is adequate for BrCOCO· to break down into Br · and 2CO; at the same time the C-C and C-Br bonds of BrCOCO · free radicals dissociate.展开更多
The multi-bond dissociation dynamics of oxalyl chloride ((ClCO)2) is investigated by ab initio calculation. Dissociation of C-Cl bond of oxalyl chloride in the ground state is of barrierless. After the absorption of a...The multi-bond dissociation dynamics of oxalyl chloride ((ClCO)2) is investigated by ab initio calculation. Dissociation of C-Cl bond of oxalyl chloride in the ground state is of barrierless. After the absorption of a photon, (ClCO)2 is excited to the first excited state and one of its C-Cl bonds is broken to yield Cl and ClCOCO* free radicals. In addition, ClCOCO* with high energy is prone to release energy (Q), and to turn into ClCOCO in the ground state. The energy (Q) is ade-quate for ClCOCO to break down into ClCO and CO, and even for ClCO into Cl and CO. The result is consistent with the experimental data that Kong reported.展开更多
基金the National Natural Science Foundation of China (Nos. 21774069, 51633003 and 21474058) for financial support。
文摘Hydrogel-based quasi-solid-state electrolytes(Q-SSEs) swollen with electrolyte solutions are important components in stretchable supercapacitors and other wearable devices. This work fabricates a supertough, fatigue-resistant, and alkali-resistant multi-bond network(MBN) hydrogel aiming to be an alkaline Q-SSE. To synthesize the hydrogel, a 2-ureido-4[1H]-pyrimidone(UPy) motif is introduced into a poly(acrylic acid) polymer chain. The obtained MBN hydrogels with 75 wt% water content exhibit tensile strength as high as 2.47 MPa, which is enabled by the large energy dissipation ability originated from the dissociation of UPy dimers due to their high bond association energy. Owing to the high dimerization constant of UPy motifs, the dissociated UPy motifs are able to partially re-associate soon after being released from external forces, resulting in excellent fatigue-resistance. More importantly, the MBN hydrogels exhibit excellent alkali-resistance ability. The UPy Gel-10 swollen with 1 mol/L KOH display a tensile strength as high as ~1.0 MPa with elongation at break of ~550%. At the same time, they show ionic conductivity of ~17 m S/cm, which do not decline even when the hydrogels are stretched to 500% strain.The excellent mechanical property and ionic conductivity of the present hydrogels demonstrate potential application as a stretchable alkaline Q-SSE.
基金the National Natural Science Foundation of China(Nos.21774069,51633003 and 21474058)for financial support。
文摘Multi-bond network(MBN) hydrogels contain hierarchical dynamic bonds with different bond association energy as energy dissipation units,enabling super-tough mechanical properties.In this work,we copolymerize a protonated 2-ureido-4[1 H]-pyrimidone(UPy)-contained monomer with acrylic acid in HCl solution.After removing excess HCl,UPy motifs are deprotonated and from dimers,thus generating an UPy-contained MBN hydrogel.The obtained MBN hydrogels(75 wt% watercontent) exhibit super-tough mechanical properties(0.39 MPa to 2.51 MPa tensile strength),with tremendous amount of energy(1.68 MJ/m^(3) to 11.1 MJ/m^(3)) dissipated by the dissociation of UPy dimers.The introduction of ionic bonds can further improve the mechanical properties.Moreover,owing to their dynamic nature,both UPy dimers and ionic bonds can re-associate after being dissociated,resulting in excellent self-recovery ability(around 90% recovery efficiency within only 1 h).The excellent self-recovery ability mainly originates from the re-association of UPy dimers based on the high dimerization constant of UPy motifs.
基金supported by the National Key Research and Development Program(No.2022YFB3304000)the National Natural Science Foundation of China(No.52275292)+5 种基金the Fundamental Research Funds for the Central Universities(No.D5000240313)the Key Research and Development Program of Shaanxi Province(No.2022GY-228)the Science and technology planning project of Xian(No.20KYPT0002-1)the Fundamental Research Funds for the Central Universities(Nos.D5000230084 and 3102022gxb002)the Shaanxi Province Key Research and Development Projects(Nos.2021LLRH08 and 2022GXLH-02-15)the Emerging Interdisciplinary Project of Northwestern Polytechnical University(No.22GH0306).
文摘Polyvinyl alcohol(PVA)-based hydrogels are widely used in the fields of tissue engineering,biomedicine,and flexible sensors due to their low cost,excellent biocompatibility,and simple gelation methods.Re-peated freeze-thaw cycles are essential for the preparation of such hydrogels.Although this process can enhance the mechanical properties of the hydrogels to a certain extent,it can also result in opacity and limited tensile performance,significantly restricting their application in wearable devices and electronic skin.This study introduced cellulose nanofibers into polyacrylamide(PAM)/PVA double interpenetrat-ing network hydrogel system,achieving the preparation of a multifunctional composite hydrogel with a“triple-network interlock”structure.Under the synergistic effects of multiple networks,multiple hy-drogen bonds,and nano-reinforcement,this composite hydrogel requires only a single freeze-thaw cycle to achieve a tensile strength exceeding 1 MPa,which is significantly higher than that of PVA hydro-gels subjected to multiple freeze-thaw cycles.The PVA-based hydrogel prepared in this work balances tensile strength(1.41 MPa),elongation(1332%),transparency(89.8%),and toughness(6.73 MJ m^(-3)).Ad-ditionally,this composite hydrogel exhibits high sensitivity(GF=8.74),rapid response(108 ms),fatigue resistance,and antibacterial properties,making it a reliable strain sensor over a wide strain range.When encapsulated on human joints,it can monitor body movements in real-time,such as movements of fin-gers,wrists,elbows,and knees,and can be integrated into peripheral circuits to achieve precise real-time control of robotic hands.This work presents a multifunctional composite hydrogel with great potential as a candidate material for tissue engineering,human-machine interaction,and high-performance wearable sensors.
基金This research was financially supported by the Key Laboratory Foundation of Polymer Materials of Gansu Province
文摘The multi-bond dissociation dynamics of oxalyl bromide （（BrCO）2） has been investigated by DFT and CIS calculations. Upon the results, conclusion could be drawn that dissociation of C-Br bond of oxalyl bromide at the ground state （So） is of barfierless. After the absorption of a photon, （BrCO）2 is excited to the first excited state and one of its C-Br bonds is broken to yield Br ·＊ and BrCOCO· ＊ free radicals. In addition, BrCOCO · ＊ with high energy is apt to release energy, and ultimately, turns into BrCOCO ·of the ground state. The energy is adequate for BrCOCO· to break down into Br · and 2CO; at the same time the C-C and C-Br bonds of BrCOCO · free radicals dissociate.
基金The authors would like to thank professor Fang D. C. for his helpful discussion. This work was supported by the National Natural Science Foundation of China (Grant No. 29713007).
文摘The multi-bond dissociation dynamics of oxalyl chloride ((ClCO)2) is investigated by ab initio calculation. Dissociation of C-Cl bond of oxalyl chloride in the ground state is of barrierless. After the absorption of a photon, (ClCO)2 is excited to the first excited state and one of its C-Cl bonds is broken to yield Cl and ClCOCO* free radicals. In addition, ClCOCO* with high energy is prone to release energy (Q), and to turn into ClCOCO in the ground state. The energy (Q) is ade-quate for ClCOCO to break down into ClCO and CO, and even for ClCO into Cl and CO. The result is consistent with the experimental data that Kong reported.
