Self-assembled nano-structure particle and method for preparing
View Patent ↗Novel, nano-structured particles are formed by introducing a selected solid of interest into a structured fluid matrix formed by a dispersion of a small molecule host vessel, such as a native or modified polysaccharide, cavitand, simple sugar, simple polyol or other similarly structured molecule known to be useful as a host vessel, in an acidic medium or other solvent, whereby the particle size of the introduced solid is reduced and or limited by incorporation into the host vessel. The simple, one-step mixing process results in stabilized colloidal dispersions of the nanoparticles useful in a wide variety of applications.
1. A process for forming a nanoparticle-based clathrate pigment composition, consisting of the steps of:
preparing a high viscosity, structured fluid matrix by heating a concentrated acid medium consisting essentially of polyphosphoric (superphosphoric 105%) acid, sulfuric acid (80 wt. % aq.), or glyoxylic acid (50% aq.) or mixtures thereof, with agitation, and adding a host vessel molecule comprising a carbohydrate that is amylose, maltodextrin or cyclodextrin, with agitation, to the acid medium,
adding a solid guest particle that is a pigment, with agitation, to the structured fluid matrix to form a mixture,
stirring the mixture at an elevated temperature for a set period of time to allow for particle size reduction and annealing of the added solid quest particles as they become physically trapped within the host vessel molecule,
quenching the mixture, and
separating unreacted host vessel molecules from the mixture to obtain a stabilized lower viscosity colloidal dispersion of nanoparticle-based clathrates comprising the solid guest particle pigment within the host vessel molecules of the structured fluid matrix,
wherein the particle size of the clathrate achieved by the process is less than about 600 nanometers.
2. The process of claim 1 wherein:
the mixture is quenched by water.
3. The process of claim 1 , wherein the temperatures under which the process is conducted range from 40 to 100° C.
4. The process of claim 2 , wherein the quenching water further comprises a stabilizing compound comprising glyoxylic acid, sulfuric acid, aldehydes, hydrazines, hydroxylamines, amines, epoxides, acrylic acid, acrylate esters, conjugated dienes, dieneophiles or mixtures thereof, an acid neutralizing compound, or combinations thereof.
5. The process of claim 2 , wherein the pigment comprises Pigment Red 122, Pigment Red 177, Magenta D 4500 J, Pigment Blue 15, Pigment Green 7, Pigment Green 36, Pigment Yellow 74, Pigment Yellow 120, Pigment Yellow 180, carbon black or graphite.
6. A colloidal dispersion of nanoparticle-based clathrates formed by the process of claim 1 .
7. An ink jet composition comprising the colloidal dispersion of claim 6 .