Instantaneous Nanopreparation Research And Technical Application Of Nano Water Dispersion System

Nanosuspension and nanoemulsion are two types of widely used colloidal materials.They present unique physicochemical properties due to their nano-scaled size.1)This thesis successfully prepared luminogen nanoparticles with an aggregation-induced emission(AIE)ingredient via the flash nanoprecipitation(FNP).For a possible application in drug tracing or medical imaging,the effects of the particle size,organic solvent,conjugate group of additives,glass transition temperature of polymeric carriers,and oily additives were studied.The mechanism of the AIE was thus explored.The work provided a guideline to select suitable additives for AIE-active composite nanoparticles.2)An energy-effective and facile method for fast preparing nanoemulsions(i.e,flash nanoemusification,F NE)was developed in this thesis.A bottom-up mechanism of the nanoemulsion formation and evolution was proposed.The feasibility of a hand operation without sophisticated pumps was confirmed via obtaining the critical Reynolds number(Re)so as the system was able to be significantly simplified.3)The FNE was extended to produce emulsions of base oil and tested the universality of the method.A capillary number(Ca)of the mixing and the surface tension of the oil were used as the indicators for predicting the feasibility of the nanoemulsion formation via the FNE.It would be beneficial to build a related theory on flash formation of colloidal materials as well as to provide guidance on a formulation selection.4)By combining the FNP and the FNE,Flash nanoformation(FNF)was for the first time proposed.In the second chapter,a hydrophobic compound,tetraphenylethylene(TPE,ACDLogP =8.41),as a model AIE molecule and an amphiphilic block copolymer(BCP),methoxy poly(ethylene glycol)-block-poly(lactic-co-glycolic acid)(mPEG-b-PLGA)as a surface stabilizer were used.The fluorescent nanoparticles with a size of?100 nm were obtained and presented an excellent AIE property.The correlation between fluorescence intensity with the particle size was investigated for the first time.The effects of drugs,macromolecule excipients and oils on the fluorescence intensity were investigated.In the third chapter,a nanoemulsion with a droplet diameter of upto 16 nm was successfully prepared by using hydrophobic oil,tangerine oil(ACDLogP = 4.37),as modle oil and either polysorbate 80(Tween 80)or BCP as an emulsifier.The effects of the organic solvent,emulsifier type,concentrations,salt and dilution on the emulsion stability were studied.The results showed that the BCP was much more effective than Tween 80 to form a small and stable emulsion in the FNE.By changing Re,higher than?2200,the minimized,constant and stable droplet size was able to be achieved.Zeta potential measurements showed that the emulsions were mainly stabilited by the hinderanc of the emulsifier absorbed on the surface the droplet,which was further confirmed by a good stability of the emulsion in a salt solution.By comparing the FNE and the conventional drop and stir(DS)method,the particles via the FNE showed a much lower size,narrower distribution and better stability than the ones via the DS.This technology has opened up a new path to meet large demands for nanoemulsions in various industries,e.g.,petrochemicals,agrochemicals pharmaceutics,foods,and cosmetics.Chapter 4 extends the application of the FNE to produce nanoemulsions of base oil.In this chapter,Tween 80,BCP and alkyl polysaccharide glycoside(APG)(8-10 and 8-14)were used as a surfactant and the nanoemulsion formulations of either mineral oil or kerosene emulsion were optimized.A mineral oil nanoemulsion with a diameter of 100 nm and a kerosene nanoemulsion with 35 nm were successfully obtained.An emulsion of silicone oil was prepared by using a surface stabilizer of either a silicon-containing surfactant,i.e.,polydimethysilicone-graft-poly(ethylene glycol)(PDMS-g-PEG,DC-193),or silica nanoparticles(10 nm).The capillary number and interfacial tension were used as the indictors to help select the suitable oil and emulsifier,expectfully being able to build a theoretical frame for the FNE.In addition,metal washing and lubricating performances of the produced nanoemulsions were evaluated.