Adsorbents for smoking articles comprising a non-volatile organic compound applied using a supercritical fluid
View Patent ↗A surface-modified adsorbent and a process for making a surface-modified adsorbent are provided. The process involves providing an adsorbent and a non-volatile organic compound to a vessel, adjusting the temperature and/or pressure to provide supercritical conditions for a supercritical fluid, and introducing the supercritical fluid into the vessel. The supercritical fluid dissolves the non-volatile organic compound, and impregnates the adsorbent with the non-volatile organic compound. The surface-modified adsorbent can be used, for example, in cut filler compositions, cigarette filters, and smoking articles. Methods for making cigarette filters, cigarettes and for smoking a cigarette comprising the surface-modified adsorbent are also provided. The surface-modified adsorbents can be used to remove one or more selected components from mainstream smoke, without removing other components, such as those that contribute to flavor.
1. A process for making a surface-modified adsorbent, said process comprising:
(i) providing at least one adsorbent in particulate form and at least one non-volatile organic compound to a vessel;
(ii) adjusting temperature and/or pressure to provide supercritical conditions in said vessel for a supercritical fluid; and
(iii) introducing the supercritical fluid into the vessel, such that the supercritical fluid dissolves the non-volatile organic compound, and wherein the supercritical fluid with the dissolved non-volatile organic compound impregnates the adsorbent to form surface-modified adsorbent particles,
wherein the adsorbent comprises activated carbon, and
wherein the non-volatile organic compound is selected from the group consisting of: squalene, squalane, phytol, and mixtures thereof.
2. The process of claim 1 , wherein the activated carbon comprises at least about 80% micropores.
3. The process of claim 2 , wherein the micropores have pore sizes of about 15 Angstroms or less.
4. The process of claim 1 , wherein the activated carbon has an average particle size from about 6 mesh to about 300 mesh.
5. The process of claim 1 , wherein the activated carbon has an average particle size from about 0.2 mm to about 1 mm.
6. The process of claim 1 , wherein the supercritical fluid is selected from the group consisting of: carbon dioxide, n-propane, n-butane, n-pentane, n-hexane, n-heptane, cyclohexane, ethanol, toluene, acetone, methyl acetate, diethyl ether, dichloromethane, dichlorodifluoromethane, trifluoromethane, carbon tetrachloride and mixtures thereof.
7. The process of claim 6 , wherein the supercritical fluid is carbon dioxide.
8. The process of claim 1 , wherein the non-volatile compound is capable of blocking pores in the adsorbent having an average size greater than about 20 Angstroms.
9. The process of claim 8 , wherein the non-volatile compound is capable of blocking pores in the adsorbent having an average size greater than about 10 Angstroms.
10. A process for making a surface-modified adsorbent, said process comprising:
(i) providing particles of activated carbon adsorbent and at least one non-volatile organic compound to a vessel;
(ii) adjusting temperature and/or pressure to provide supercritical conditions in said vessel for carbon dioxide; and
(iii) introducing supercritical carbon dioxide into the vessel, such that the supercritical fluid dissolves the non-volatile organic compound, and wherein the supercritical fluid with the dissolved non-volatile organic compound impregnates the particles of activated carbon to form a surface-modified adsorbent,
wherein the non-volatile organic compound is selected from the group consisting of squalene, squalane, phytol, and mixtures thereof.
11. A process of making a cigarette filter, comprising:
(a) preparing a surface-modified adsorbent by the process of claim 1 ; and
(b) incorporating the surface-modified adsorbent into a cigarette filter.
12. A process of making a cigarette, comprising:
(a) preparing a surface-modified adsorbent by the process of claim 1 ; and
(b) incorporating the surface-modified adsorbent into a cigarette.