Sonication-triggered instantaneous gel-to-gel transformation.
Two new peptide-based isomers containing cholesterol and naphthalic groups have been designed and synthesized. We found that the position of L-alanine in the linker could tune the gelation properties and morphologies. The molecule with the L-alanine residue positioned in the middle of the linker (1b) shows better gelation behavior than that with L-alanine directly linked to the naphthalimido moiety (1a). As a result, a highly thermostable organogel of 1b with a unique core-shell structure was obtained at high temperature and pressure in acetonitrile. Moreover, the gels of 1a and 1b could undergo an instantaneous gel-to-gel transition triggered by sonication. Ultrasound could break the core-shell microsphere of 1b and the micelle structure of 1a into entangled fibers. By studying the mechanism of the sonication-triggered gel-to-gel transition process of these compounds, it can be concluded that ultrasound has a variety of effects on the morphology, such as cutting, knitting, unfolding, homogenizing, and even cross-linking. Typically, ultrasound can cleave and homogenize pi-stacking and hydrophobic interactions among the gel molecules and then reshape the morphologies to form a new gel. This mechanism of morphology transformation triggered by sonication might be attractive in the field of material storage and controlled release.
Yu
Xudong
X
Department of Chemistry and Laboratory of Advanced Materials, Fudan University, 220 Handan Road, Shanghai 200433, China.
Liu
Qian
Q
Wu
Junchen
J
Zhang
Mingming
M
Cao
Xinhua
X
Zhang
Song
S
Wang
Qi
Q
Chen
Liming
L
Yi
Tao
T
D000409:Alanine / Q000031:analogs & derivatives* / Q000737:chemistry; D002784:Cholesterol / Q000031:analogs & derivatives* / Q000138:chemical synthesis* / Q000737:chemistry; D005782:Gels / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D008958:Models, Molecular; D015394:Molecular Structure; D009281:Naphthalenes / Q000138:chemical synthesis* / Q000737:chemistry; D010455:Peptides / Q000138:chemical synthesis* / Q000737:chemistry; D013010:Sonication
D005782:Gels; D009281:Naphthalenes; D010455:Peptides; D002784:Cholesterol; D000409:Alanine