Theoretical and Experimental Study of the Amphiphilic Block Copolymer poly (4-chloromethylstyrene) -b-poly (ethylene oxide)
H.Khomidja , N.Nemiche* , F.Z.Sebba
In recent years, the significant evolution in the computer field and the progress made in quantum chemistry [1-3] calculation methods make it possible to give a good prediction and a good description of the electronic properties of a given entity. These circumstances favor a more common use of these tools in different fields of chemistry for the comparison of experimental and calculated results, as well as a better understanding of the reaction mechanisms. For this we combine two methods: the theory and the experimental on the amphiphilic copolymers which constitute currently a particular class, which arouses a lot of interest as well in the field of the fundamental research as in the industrial field, in particular the pharmaceutical field where they are more particularly used in the vectorization of active principles because of their ability to encapsulate, transport and release some non-water soluble molecules. Our work will be divided into two parts: the experimental part which consists of preparing a block amphiphilic copolymer with a well-defined structure that can adopt micelle type morphologies poly (4-chloromethylstyrene) -b-poly (ethylene oxide) and analyzes by the different structural analysis techniques: nuclear magnetic resonance (1 HNMR, 13CNMR), absorption spectroscopy (IR) and gel permeation chromatography (GPC), SEM. The theoretical part: or we have studied by the theory of the functional density DFT synthetic amphiphilic copolymer poly (4-chloromethylstyrene) -b-poly (ethylene oxide). Using three different bases B3LYP, 6-31G and 6-31G ** for minimizing energy and choosing the best base. The results were also developed by theoretical analysis of 1H NMR, 13C NMR, and IR spectra.
The study and sizing of sorption machine evaporators are based on the prediction of the heat transfer coefficient at atmospheric pressures, but in the literature we only find correlations modeled from experiments for a wide range of pressure, where the majority of the data are above atmospheric pressure; A review of the experiments of boiling at sub-atmospheric pressures was carried out and compared to four known correlations for three types of fluids, which are water, hydrocarbons and refrigerants; The results obtained showed deviations of the predicted data from the experimental values for three correlations and convincing results for the fourth.