A Highly Stretchable and Autonomous Self-Healing Polymer Based on Combination of Pt···Pt and π-π Interactions.

A new self-healing polymer has been obtained by incorporating a cyclometalated platinum(II) complex Pt(C∧ N∧ N)Cl (C∧ N∧ N = 6-phenyl-2,2'-bipyridyl) into a polydimethylsiloxane (PDMS) backbone. The molecular interactions (a combination of Pt···Pt and π-π interactions) between cyclometalated platinum(II) complexes are strong enough to crosslink the linear PDMS polymer chains into an elastic film. The as prepared polymer can be stretched to over 20 times of its original length. When damaged, the polymer can be healed at room temperature without any healants or external stimuli. Moreover, the self-healing is insensitive to surface aging. This work represents the first example where the attractive metallophilic inter-actions are utilized to design self-healing materials. Moreover, our results suggest that the stretchability and self-healing properties can be obtained simultaneously without any conflict by optimizing the strength of crosslinking interactions.

A Stiff and Healable Polymer Based on Dynamic-Covalent Boroxine Bonds.

A stiff and healable polymer is obtained by using the dynamic-covalent boroxine bond to crosslink PDMS chain into 3D networks. The as-prepared polymer is very strong and stiff, and can bear a load of more than 450 times its weight. When damaged, it can be completely healed upon heating after wetting.

A Highly Stretchable Polymer that Can Be Thermally Healed at Mild Temperature.

Combining stretchability and self-healing properties in a man-made material is a challenging task. For an efficient self-healing material, weaker dynamic or reversible bonds should be presented as crosslinks so that they will first break upon damage and then reform after healing, which is not favorable when developing elastic materials. In this work, by incorporating dynamic Fe(III)-triazole coordination bonds into polydimethylsiloxane (PDMS) backbone, a highly elastic polymer is obtained that can be thermally healed at mild temperature. The as-prepared polymer can be stretched to 3400% strain at low loading speed (1 mm min(-1) ). When damaged, the polymer can be thermally healed at 60 °C for 20 h with a healing efficiency of over 90%. The good mechanical and healable properties of this polymer can be ascribed to the unique coordination bond strength and coordination conformation of Fe(III)-triazole coordination complex.

A novel photo-responsive europium(III) complex for advanced anti-counterfeiting and encryption.

A novel europium(iii) complex simultaneously exhibiting photocolorimetric and photofluorometric behavior was obtained. Multiple distinguishable identities can be obtained and reversibly modulated using light as external stimuli. With this novel photo-responsive complex, double encryption and advanced anti-counterfeiting were realized.

A self-healing PDMS polymer with solvatochromic properties.

Coordination bonds are effective for constructing functional self-healing materials due to their tunable bond strength and metal-ion-induced functionalities. In this work, we incorporate a cobalt(II) triazole complex into a polydimethylsiloxane (PDMS) matrix. The resulting polymers show solvatochromic behaviour as well as self-healing properties.

[Study on the relationship of family functioning and subjective well-being of junior-high school students].

OBJECTIVE: To describe the status of subjective well-being among junior high school students in a city of Jiangxi Province and to explore the relationship between family functioning and subjective well-being. To explore the relationship between growth environment and subjective well-being among junior high school students in the perspective of family functioning and to provide basis and data for the mental health education among junior high school students. METHODS: 630 students in a junior high school in Jiangxi Province were sampled by stratified cluster sampling, and 103 junior high school students from 18 villages were sampled by household survey. They were investigated by subjective well-being scale for adolescents and Family Assessment Device. RESULTS: (1)The overall subjective well-being of junior high school students was in the lower-middle level. Regarding all the dimensions of subjective well-being, they had the highest satisfaction on family and friendship, lowest academic satisfaction, low positive as well as passive emotion. (2)Girls had higher satisfaction on friendship and freedom than that of boys; children from families with more than one kids had more negative emotion than that of single child; boarding students had higher satisfaction on family, academics and freedom than that of non-boarding students; family residence and structure affected the satisfaction on family; grade and learning achievement affected some dimensions of subjective well-being among junior high school students. (3)Pearson correlation analysis and multiple linear regression analysis showed that some dimensions of family functioning were related to certain dimensions of subjective well-being among junior school students, and family functioning could predict the level of subjective well-being. CONCLUSION: The overall subjective well-being of junior high school students is in the lower-middle level, and further improving is needed. Family functioning has a great influence on junior school students' subjective well-being. Junior high school students who have healthy family functioning are more likely to have higher life satisfaction, and tend to experience higher subjective well-being.