Preparation, Characterization And Performance Study Of Supramolecular Nanocarriers

In this dissertation, a novel core-shell type supramolecular nanocarrier was prepared through the self-assembly of calixarenes on hyperbranched polymer. This supramolecular nanocarrier was characteristic of encapsulating simultaneously two kinds of guest molecules with different properties in the state of site-isolation. The details were as follows:1. Six amphiphilic compounds utilized as the shells in the core-shell type supramolecular nanocarriers were synthesized, which were 1-(4-hydroxyphenyl)octan-1-one (C8Phenol), 1-(4-hydroxyphenyl)dodecan-1-one (C12Phenol), 2-(4-octanoylphenoxy)acetic acid (C8Acid), 2-(4-dodecanoyl -phenoxy)acetic acid (C12Acid), p-octanoylcalix[4]arene (C8Calix) and p-dodecanoylcalix[4]arene (C12calix). According to the difference of head-groups these compounds could be classified as three series that is Phenol, Acid and Calix, respectively.2. Hyperbranched polyethylenimine (HPEI) was simply mixed with a solution of synthesized amphiphilic compounds in chloroform. This resulted in the novel supramolecular complexes through the noncovalent interaction. The formed supramolecualr complexes were characterized by 1H NMR and dynamic light scattering. It was showed that the obtained supramolecualr complexes were to display the structure of unimolecular inverted micellar.3. All the supramolecualr complexes formed by the interaction of HPEI with the different series of compounds (HPEI-Calix, HPEI-Acidå’ŒHPEI-Phenol) could accommodate the anionic water-soluble Methyl Orange (MO) guests into the HPEI core, resulting in the phase transfer of MO from water into chloroform phase. Compared with HPEI-Acid and HPEI-Phenol, HPEI-Calix exhibited obvious advantages: (1) HPEI-Calix showed the highest encapsulation capacity for MO molecules, and the encapsulation capacity was in the order: HPEI-Calix > HPEI-Acid > HPEI-Phenol; (2) The MO encapsulation capacity of HPEI-Calix with low ratio of hydroxyl to amino groups (OH/N) was similar to that with high OH/N value, pointing out the high efficiency of Calix as shell compounds; (3) The MO encapsulation capacity of HPEI-AC4 was also pH sensitive, which reached the maximum loading at pH=6.5. The loaded MO molecules could be totally released when the pH value was reduced to be around 4.5 or raised to be around 9.5, and this process was reversible; (4) HPEI-Calix could not only accommodate the anionic MO with the HPEI core, but also simultaneously load the cationic water-soluble dye Methyl Blue (MB) molecules using the Calix formed shell, realizing the site isolation of the two kind of functional units. The number of MO and MB encapsulated by HPEI-AC4 could be controlled by varying the ratio of HO/N.