Figure 2 (a) Photographs, (b) storage modulus (G’ ) and (c) loss modulus (G’ ’ ) with versus scanning frequency (ω ) for the gels G1 , G2 , andG3 .(G1 : adding 10 mmol M3 and 180 mmolM2 into 100 mmol M1 ; G2 : adding 20 mmolM3 and 160 mmol M2 into 100 mmol M1 ;G3 : adding 30 mmol M3 and 140 mmol M2 into 100 mmol M1 )
In order to characterize the formation of poly[2]catenane gels and the changes in the crosslinking degree, we performed linear oscillation sweep experiments on three gels G1 , G2 , andG3 with different crosslinking degrees . Gels G1 ,G2 , and G3 were obtained by adding 10 mmol M3 and 180 mmol M2 to 100 mmol M1 , 20 mmol M3 and 160 mmol M2 to 100 mmol M1 , 30 mmol M3 and 140 mmol M2 to 100 mmol M1 , respectively. As shown in Figure 2a, three gels were formed by adding different amounts ofM2 and M3 . The variation of storage modulus (G ’) and loss modulus (G ’ ’) with frequency in chloroform for the fabricated gels was shown in Figure 2b,c. The storage modulus of all three gels was larger than the loss modulus and was independent of the frequency, which proved that the formation of gel states.[25-26] Comparing the storage modulus and loss modulus of gels G1 , G2 , and G3 , it could be found that with the addition of M3 , the storage modulus and loss modulus of gel G1 , G2 and G3 increased significantly: the plateau value of the storage modulus of the gels increased from 5 × 104 to 8 × 104, and the value of the loss modulus of the gels rose by one order of magnitude. This indicated that the crosslinking degree increased gradually with the increase of the incorporation amount ofM3 (from 10 mmol M3 to 30 mmolM3 ).[27]