Preparation And Properties Of PH/Temperature Responsive Hollow Nanospheres

Recently, hollow nanospheres with an empty core domain and a polymer shell have encapsulation capability, controllable surface permeability and surface functionality has wide applications in many fields, including catalysis,controlled drug-delivery systems, artificial cells, nanoreactions, and photonic crystals. While, as the use of materials,it has made bad pollution of the environment. So it is important to synthesize a kind of hollow nanospheres to decrease pollution. In this article, the founctional polymer is introducted to the hollow naonospheres materials. The detailed contents are as below.1、Base on ATRP methods, bromide functionalized silica nanoparticles are used as sacrificial templates to graft responsive polymer PNIPAM. Then Pt-BMA is selectively grafted by ATRP. The silica followed by cross-linking with cystamine dihydrochloride and removal of the silica template in the presence of hydrofluoric acid, respectively. The inner layer is the temperature sensitive PNIPAM brush and the out layer is composed of crosslinked pH-responsive PMAA. By using this approach, we can precisely control the thickness, size and the thickness of the polymer shell by adjusting the molecular weight of the polymers.2、The resultant polymer hollow nanospheres were water soluble, temperature sensitive, pH responsive and non-toxic to human cells at low concentration, which are favorable to be utilized as drug carriers for pH responsive, temperature responsive and biodegradation loading and releasing properties of the polymer nanospheres. The polymer nanospheres cross-linked by disulfide contained molecules can be biodegraded into linear polymer chains, while the drug release efficiency was correspondingly enhanced.