Phase inversion composition method

Yang, H.J., Cho, W.G. and Park, S.N. (2009) Stability of oil-in-water nanoemulsions prepared using the phase inversion composition method. Journal of Industrial and Engineering Chemistry,... 

Sole I, Pey CM, Maestro A, Gonzalez C, Porras M, Solans C, et al. Nano-emulsions prepared by the phase inversion composition method preparation variables and scale up. J Colloid Interface Sci 2010 344 417-23. 

Four methods may be applied for the preparation of nanoemulsions (covering the droplet radius size range 50-200 nm) use of high pressure homogenizers (aided by appropriate choice of surfactants and cosurfactants) application of the phase inversion composition method apphcation of the phase inversion temperature (PIT) concept dilution of a microemulsion. 

PA 6/ABS ABS 0-100 wt% Hydrophobic nanosilica At interface when ABS forms the dispersed phase. In ABS phase when ABS is a continuous phase The change in matrix and dispersed phase viscosity ratio shifts the phase inversion at higher ABS composition in the presence of nanosilica. The phase inversion composition was determined by various characterization techniques such as DSC, DMA, rheological behavior, and solvoit extraction method Liu et al. 2013... 

The conditions for obtaining O/W nano-emulsions with a minimum droplet size and consequently low polydispersity by phase inversion emulsification methods (PIT and PIC) can be summarized as follows A bicontinuous microemulsion or a lamellar liquid crystalline phase (D or L , respectively), with all the oil dissolved, must be formed immediately before reaching the final two-phase region where the nano-emulsions form. These are composition conditions necessary but not sufficient, because the kinetics of incorporation of oil to these phases or the coalescence of droplets can make the nano-emulsion droplet size also dependent on preparation variables such as mixing rate and aqueous phase addition rate for the PIC method, or cooling rate for the PIT method. 

Symmetric membranes and asymmetric membranes are two basic types of membrane based on their structure. Symmetric membranes include non-porous (dense) symmetric membranes and porous symmetric membranes, while asymmetric membranes include integrally skinned asymmetric membranes, coated asymmetric membranes, and composite membranes. A number of different methods are used to prepare these membranes. The most important techniques are sintering, stretching, track-etching, template leaching, phase inversion, and coating (13,33). 

Membranes for vapor removal from air have a structure similar to the prism membrane, but they are prepared on a different principle.Aromatic PEI is used to produce a porous substrate membrane by the dry-wet phase inversion method. This polymer was chosen over PS/PES because of the higher durability of PEI to organic vapors. Unlike an asymmetric PS substrate for the prism membrane, the top layer of asymmetric PEI membrane has a large number of pores, the size of which is equivalent to those of UF membranes. When a layer of silicone rubber is coated on the top layer of the porous substrate membrane, the silicone rubber layer will govern the selectivity and the porous support will provide only mechanical strength to the composite membrane. Because the permeabilities of water and organic vapors through the silicone... 

Fabrication of a thin film composite membrane is typically a more expensive route to reverse osmosis membranes because it involves a two-step process versus the one-step nature of the phase inversion film casting method. However, it offers the possibility of each individual layer being tailor-made for maximum performance. The semipermeable coating can be optimized for water flux and solute rejection characteristics. The microporous sublayer can be optimized for porosity, compression resistance and strength. Both layers can be optimized for chemical resistance. In nearly all thin film composite reverse osmosis membranes, the chemical composition of the surface barrier layer is radically different from the chemical composition of the microporous sublayer. This is a common result of the thin film composite approach. 

Curcumin-loaded CS/cellulose microcrystal composite films can be prepared by the vapour induced phase inversion method and show good antimicrobial action against bacteria and fungi. Cellulose fibres made of CS/lignosulfonate (LS) multilayers exhibit... 

Microemulsions can be prepared by controlled addition of lower alkanols (butanol, pentanol, and hexanol) to milky emulsions to produce transparent solutions comprising dispersions of either water-in-oil (w/o) or oil-in-water (o/w) in nanometer or colloidal dispersions (-100 nm). The alkanols (called cosurfactants) lower the interfacial tension between oil and water sufficiently for almost spontaneous formation. The miscibility of oU, water, and amphiphile (surfactant plus cosurfactant) depends on the overall composition, which is systan specific. Phase inversion method is further divided into two types ... 

Phase inversion methods are based on spontaneous O/W nanoemulsion formation induced by controlling the interfacial behavior, from predominantly lipophilic to predominantly hydrophilic, of the surfactants at the O/W interface, in response to changes in system compositions or environmental conditions. ... 

---