Articles and methods for forming liquid films on surfaces, in devices incorporating the same
Embodiments described herein relate to articles and methods for forming liquid surface films on the interior surfaces of containers for holding one or more products comprising one or more Bingham plastic materials. Bingham plastic materials behave as a solid under no or low shear stress, and behave as viscous liquids when an applied shear stress exceeds a yield stress. In some embodiments, a container for containing a product includes an interior surface and a liquid disposed on the interior surface. Before introduction of a product into a container, the liquid may be surrounded by air. The liquid-air interface in contact with the interior surface makes a contact angle, θ os(a) , with respect to the interior surface of the container, of about 0°. After a product has been introduced to the container, the liquid is at least partially covered by the product. The liquid-product interface in contact with the interior surface, makes a contact angle, θ os(p) , with respect to the interior surface, of less about 60°. The subscript “o” denotes the liquid, subscript “s” denotes the interior surface, subscript “a” denotes air, and subscript “p” denotes a product. In some embodiments, the contact angle θ os(p) can be less than about 50°, less than about 40°, or less than about 30°.
1. An apparatus for containing a product, the apparatus comprising:
a container having an interior surface; and
a liquid disposed on the interior surface, the liquid configured to have a contact angle, ⊖ os(p) , between about 1° and about 60° with a product, ⊖ os(p) measured with respect to the interior surface, the liquid covering the interior surface in the absence of the product, the liquid separated into patches upon contact between the liquid and the product in a region of the interior surface contacted by the product, the patches covering most of the interior surface,
wherein subscript “o” denotes the liquid, subscript “s” denotes the interior surface, and subscript “p” denotes the product.
2. The apparatus of claim 1 , wherein the contact angle θ os(p) is between about 1° and about 40°.
3. The apparatus of claim 2 , wherein the contact angle θ os(p) is between about 1° and about 30°.
4. The apparatus of claim 1 , wherein θ os(p) is a contact angle of sessile drops.
5. The apparatus of claim 1 , wherein θ os(p) is a receding contact angle.
6. The apparatus of claim 1 , wherein the liquid is an additive or contains an additive.
7. The apparatus of claim 6 , wherein the additive is an FDA approved drug or an inactive drug ingredient.
8. The apparatus of claim 1 , wherein the liquid is flavorless or odorless.
9. The apparatus of claim 1 , wherein the liquid has a viscosity of less than 1000 cP at room temperature.
10. The apparatus of claim 1 , wherein the liquid fully wets the interior surface in the absence of the product.
11. An apparatus comprising:
a container having an interior surface defining an inner volume;
a liquid disposed on the interior surface; and
a product disposed in the inner volume of the container, the product at least partially immiscible with the liquid, wherein the interior surface and the liquid are configured such that: (i) the liquid is separated into patches upon contact between the liquid and the product in a region of the interior surface contacted by the product, the patches covering most of the interior surface, and (ii) a liquid-product interface has a contact angle, ⊖ os(p) , of between about 1° and about 60° with respect to the interior surface, wherein subscript “o” denotes the liquid, subscript “s” denotes the interior surface, and subscript “p” denotes the product.
12. The apparatus of claim 11 , wherein the contact angle θ os(p) is between about 1° and about 40°.
13. The apparatus of claim 12 , wherein the contact angle θ os(p) is between about 1° and about 30°.
14. The apparatus of claim 11 , wherein θ os(p) is a contact angle of sessile drops.
15. The apparatus of claim 11 , wherein the product is a food or a drug.
16. The apparatus of claim 11 , wherein the product is toothpaste.
17. The apparatus of claim 11 , wherein the liquid has a first density and the product has a second density, the first density approximately equal to the second density.
18. The apparatus of claim 11 , wherein the liquid fully wets the interior surface in the absence of the product.
19. An apparatus comprising:
a substrate having a surface;
a liquid having a first density disposed on the surface; and
a product having a second density disposed and configured to contact the liquid, the second density approximately equal to the first density, wherein the surface and the liquid are configured such that: (i) the liquid covers the surface in the absence of the product, (ii) the liquid is separated into patches upon contact between the liquid and the product in a region of the surface contacted by the product, the patches covering most of the surface, and (iii) a liquid-product interface has a contact angle, ⊖ os(p) , of between about 1° and about 60° with respect to the surface, wherein subscript “o” denotes the liquid, subscript “s” denotes the interior surface, and subscript “p” denotes the product.
20. The apparatus of claim 19 , wherein the contact angle θ os(p) is between about 1° and about 40°.
21. The apparatus of claim 20 , wherein the contact angle θ os(p) is between about 1° and about 30°.
22. The apparatus of claim 19 , wherein the product is a food or a drug.
23. The apparatus of claim 19 , wherein the product is toothpaste.
24. The apparatus of claim 19 , wherein the liquid fully wets the surface in the absence of the product.