Ultrasound switch and thermal self-repair of morphology and surface wettability in a cholesterol-based self-assembly system.
Ultrasound switch and thermal self-repair of morphology and surface wettability in a cholesterol-based self-assembly system.
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DOI：
10.1002/anie.200703946
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发表时间：
2008-01
影响因子：
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通讯作者：
Junchen Wu;T. Yi;Tianmin Shu;Mengxiao Yu;Zhiguo Zhou;Miao Xu;Yifeng Zhou;Huijun Zhang;
中科院分区：
文献类型：
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作者：
Junchen Wu;T. Yi;Tianmin Shu;Mengxiao Yu;Zhiguo Zhou;Miao Xu;Yifeng Zhou;Huijun Zhang;
近年来，刺激响应性低分子量有机凝胶[1]由于其潜在的应用，如药物递送、[2]机械作用等，在化学、生物学和材料科学等领域受到越来越多的关注。（例如，形状或尺寸的触发变化），[3]亲水性/疏水性调节，[4]光学和电子效应，[5]等等。尽管有大量报道的反应材料，但最常用的刺激包括光，[5]反应，[2]和热。[6]然而，应该注意的是，可以通过声音[7]和触变性[8]控制甚至切换的智能或自适应凝胶的开发也非常有吸引力。Sijbesma [9]和Naota [7a，c]的研究组对超声诱导可逆凝胶化的研究做出了大部分贡献。Naota [7a，c]和Zhang [10]团队首次独立观察到氢键胶凝剂中超声诱导的胶凝。考虑到超声波刺激对凝胶化的特殊分布，特别是对氢键凝胶的形成，在不同环境中的氢键的明智设计以及氢键与其他相互作用如π··· π相互作用和疏水相互作用以及空间位阻的平衡，是满足超声响应要求所必需的。在此，我们报道了三个具有ALS [11]（芳香族基团A，连接基团L，甾族基团S）结构特征的化合物1a-c（方案1）的设计和合成，其中萘单元用作芳香族基团A，胆固醇用作甾族基团S。将荧光团（萘单元）引入到这样的体系中不仅适用于光子软材料，而且还可以用于光子晶体的研究。
Recently, stimuli-responsive low-weight molecular organogels [1] have been the subject of increasing attention in areas ranging from chemistry and biology to materials science for their potential applications, such as drug delivery,[2] mechanical action (for example, triggered changes in shape or size),[3] hydrophilicity/hydrophobicity modulation,[4] optical and electronic effects,[5] and so on. Despite a wide range of reported responsive materials, the mostly used stimuli involve light,[5] reaction,[2] and heat.[6] However, it should be noted that development of a smart or adaptive gel which can be controlled or even switched by sound [7] and thixotropy [8] is also very appealing. The groups of Sijbesma [9] and Naota [7a, c] have contributed the majority of the studies on ultrasoundinduced reversible gelation. However, there is still no report on a functionality change or even switch induced by ultrasound stimuli.The Naota [7a, c] and Zhang [10] groups independently observed ultrasound-induced gelation in hydrogen-bonded gelators for the first time. Taking into account the special distribution of ultrasonic stimuli for gelation, especially for H-bonding gel formation, the judicious design of the H bonds in a different environment and the balance of the H bonds with other interactions such as π··· π interactions and hydrophobic interactions, as well as the steric hindrance, are necessary to satisfy the ultrasound-responsive requirements. Herein, we report the design and synthesis of three compounds 1a–c (Scheme1) with ALS [11](aromatic group A, linker L, steroidal group S) structural character, in which a naphthalic unit was used as aromatic group A and cholesterol was used as steroidal group S. The introduction of a fluorophore (naphthalic unit) into such a system is not only applicable to photonic soft materials but also for the facile study of