WATER-SOLUBLE TACKINESS COMPOSITION

Abstract

A water-soluble composition may include: a solution of polyvinyl alcohol (PVA) or of polyvinylpyrrolidone (PVP); CaCl.sub.2 and/or MgCl.sub.2 in a range of from 10 to 50 wt. %. The composition may include: polyvinyl alcohol or polyvinylpyrrolidone in a range of from 10 to 20 wt. % in an aqueous solution; glycerol in a range of from 20 to 40 wt. %; and CaCl.sub.2 and/or MgCl.sub.2 in a range of from 10 to 30 wt. %.

Claims

1. A method of collecting particles on a surface, the method comprising: contacting a particle with a water-soluble composition, wherein the water-soluble composition comprises: a solution comprising polyvinyl alcohol or polyvinylpyrrolidone; and CaCl2 and/or MgCl2 in a range offrom 10 to 50 wt. %.

2. The method of claim 1, wherein the composition further comprises glycerol in up to 50 wt. %.

3. The method of claim 1, wherein the composition comprises: the polyvinyl alcohol or the polyvinylpyrrolidone in a range of from 10 to 20 wt. % in an aqueous solution; glycerol in a range of from 20 to 40 wt. %; and the CaCl2 and/or the MeCl2 in a range of from 10 to 30 wt. %.

4. The method of claim 1, wherein the composition comprises: the polyvinyl alcohol or the polyvinylpyrrolidone in 10 wt. % in water; glycerol in 30 wt. %; and the CaCl2 in 20 wt. %.

5. A particle-collecting device, comprising: a support comprising a collecting surface; and the water-soluble material of claim 1, deposited on the collecting surface.

6. A mixture, comprising: particles on a surface; and an aqueous solution comprising (i) polyvinyl alcohol or polyvinylpyrrolidone and (ii) CaCl.sub.2 and/or MgCl.sub.2 in a range of from 10 to 50 wt. %, wherein the solution contacts at least one particle.

7. The mixture of claim 6, wherein the composition further comprises glycerol in up to 50 wt. %.

8. The mixture of claim 6, wherein the solution comprises: water; the polyvinyl alcohol or the polyvinylpyrrolidone in a range of from 10 to 20 wt. % in; glycerol in a range of from 20 to 40 wt. %; and the CaCl.sub.2 and/or the MgCl.sub.2 in a range of from 10 to 30 wt. %.

9. The mixture of claim 6, wherein the composition comprises: the polyvinyl alcohol or the polyvinylpyrrolidone in 10 wt. % in water; glycerol in 30 wt. %; and the CaCl.sub.2 in 20 wt. %.

10. The method of 1, wherein the solution comprises the polyvinylpyrrolidone.

11. The method of 1, wherein the solution comprises the polyvinylpyrrolidone.

12. The method of 1, wherein the composition comprises the CaCl.sub.2.

13. The method of 1, wherein the composition comprises the MgCl.sub.2.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0027] Other characteristics and advantages will become apparent in the detailed description which follows, made with regard to the appended drawings, in which:

[0028] FIGS. 1A and 1B represent an implementational example of a particle-collecting device, for example produced in the form of a roller;

[0029] FIG. 2 shows the different stages which are employed for a collecting of particles using the particle-collecting device represented in FIG. 1A;

[0030] FIG. 3 shows a diagram showing the collecting efficiency as a function of the storage period of a collecting device.

DETAILED DESCRIPTION OF AT LEAST ONE EMBODIMENT

[0031] A particle-collecting device 1 as represented in FIGS. 1A and 1n FIG. 1B comprises, for example, a support 2 provided with a collecting surface 30. In this implementation, the support 2 can be formed by a roller in the form of a cylinder of revolution exhibiting a lateral surface forming said collecting surface 30. The roller can be fitted rotating about a rod 4 forming an axis of rotation (X). The rod 4 can be connected to a gripping handle 5 of the device.

[0032] The device comprises a water-soluble material, at least partially covering its collecting surface 30, advantageously covering the entire collecting surface 30 of the support.

[0033] The water-soluble material is provided in the form of a gel 3 or of a film. The term gel is understood to mean a material which comprises a sufficient viscosity, notably of between 500 MPa.Math.s and 50 000 MPa.Math.s.

[0034] The gel 3 is deposited on the collecting surface 200 of the support 2. In the case of a support in the form of a roller, it is thus deposited on the lateral surface of the roller.

[0035] The support 2 can be made entirely of a non-deformable material, for example a hard plastic, or of an elastically deformable material, such as a deformable foam, such as, for example, a polymer foam, for example of polyurethane (PU), polyvinyl chloride (PVC), polyethylene (PE) or silicone type.

[0036] The principle of a collecting of particles is illustrated by FIG. 2.

[0037] With reference to FIG. 2, the various stages of the collecting method carried out using a collecting device 1 as described above are as follows: [0038] E1: The device 1 is ready for use and does not require any preparation. This is because the gel 3 is already present on the collecting surface 30 of the roller and the device is always ready for use. [0039] E2: the roller is affixed to the surface S1 to be sampled (flat surface here in this example) so as to bring the gel 3 present on the roller into contact with the surface S1 to be sampled. The passage of the roller over the surface S1 to be sampled makes it possible to drive the roller in rotation about its axis (X). During the application of the roller, the particles P present on the surface S1 to be sampled are detached from the surface to be sampled and will stick to the gel 3. Several passes may be necessary. [0040] E3: The particles P are collected on the collecting surface 30 of the device. In order to be recovered, the collecting surface is immersed, at least partially or even entirely, in an aqueous solution 60, for example an aqueous buffer (for example, phosphate-buffered saline-PBS), present in a collecting tank 6. To facilitate the immersion, the support 2 in its entirety can be separated from the remainder of the device. [0041] E4: During the immersion of the collecting surface, the gel 3 dissolves in the aqueous solution 60, thus releasing the collected particles P into the solution. An analysis of the aqueous solution 60 will subsequently make it possible to identify the particles P which have been collected.

[0042] According to the invention, the gel is composed of: [0043] a solution of polyvinyl alcohol (PVA) or of polyvinylpyrrolidone (PVP) present in a proportion of between 5% and 30% in an aqueous solution, [0044] from 10% to 50% by weight of a compound chosen from: [0045] a salt, such as CaCl.sub.2 or MgCl.sub.2, [0046] from 0% to 50% by weight of glycerol.

[0047] It should be noted that the presence of glycerol is optional.

[0048] The PVP solution is obtained, for example, by dissolving 13 g of polyvinylpyrrolidone in 150 ml of distilled water. After complete dissolution, 30% by weight of glycerol and then 20% by weight of CaCl.sub.2 are added, for example.

[0049] Advantageously, a composition according to the invention is as follows: [0050] from 10% to 20% of PVA or PVP in water, then [0051] from 20% to 40% of glycerol, and [0052] from 10% to 30% by weight of MgCl.sub.2 or CaCl.sub.2 in the solution.

[0053] A preferential composition is, for example, as follows: [0054] 10% of PVP or PVA in water, then [0055] 30% of glycerol, and [0056] 20% by weight of CaCl.sub.2 in the solution.

[0057] According to a particular aspect of the invention, by adding a salt, such as CaCl.sub.2 or MgCl.sub.2, the drying of the gel is delayed and the sticky characteristics of the material are preserved over time.

[0058] The salt chosen is advantageously that composed of CaCl.sub.2.

[0059] According to a distinguishing feature, the gel can thus be deposited on the collecting surface of the roller in order to obtain complete covering of its surface.

[0060] The surface of the roller, thus covered, is subsequently heated for a further length of time in an oven in order to dry the gel on the surface of the roller. The roller is then ready for use. On leaving the oven, the roller is surrounded by a non-stick film in order to protect the sticky gel.

[0061] The roller can be stored at atmospheric pressure or deposited in a bag and placed under vacuum.

[0062] Of course, the gel might be deposited on the collecting surface of a collecting device having another architecture (cotton swab, brush, sponge, sphere, beads, and the like).

[0063] It should be noted that the composition described above might be employed for applications other than the collecting of particles, such as, for example, as hydrogel in ECG or EEG measurements, or as adhesive which does not dry or dries very slowly.

[0064] The tackiness of the composition was tested during two tests.

[0065] It was first tested for the collecting of polystyrene beads of 5 m to 10 m in diameter, distributed over a surface area of 1 m.sup.2.

[0066] For the polystyrene beads, the protocol was as follows: [0067] Stage No. 1: Deposition of the beads contained in an aqueous solution on the surface to be treated.

[0068] Deposition is carried out by dispensing drops of liquid on the surface or using a spray which dispenses drops containing the beads on the surface. [0069] Stage No. 2: Waiting for the complete drying of the drops containing the beads on the surface-4 h at ambient temperature. [0070] Stage No. 3: Passing the roller over the surface. [0071] Stage No. 4: Introducing the roller into a tank containing 10 ml of aqueous solution. [0072] Stage No. 5: Stirring (30 seconds) the tank in order for the water contained in the tank to be in contact with the surface of the roller and to dissolve the sticky film. [0073] Stage No. 6: Recovering a calibrated volume of solution (20 l) and depositing on a counting slide. [0074] Stage No. 7: Counting the number of beads recovered in the 20 l sample and comparing with the amount of beads initially deposited on the surface.

[0075] The collecting principle is also validated with regard to Bacillus thuringiensis spores.

[0076] Protocol used for Bacillus thuringiensis spores [0077] Stage No. 1: Preparation of the spore solution with counting of the spores in the initial solution. [0078] Stage No. 2: Deposition is carried out by dispensing, on the surface, a defined volume (1 ml) of the liquid drops or using a spray which dispenses drops containing the spores on the surface. [0079] Stage No. 2: Waiting for the complete drying of the drops containing the spores on the surface-4 h at ambient temperature. [0080] Stage No. 3: Passing the roller over the surface. [0081] Stage No. 4: Introducing the roller into a tank containing 10 ml of aqueous solution. [0082] Stage No. 5: Stirring (30 seconds) the tank in order for the water contained in the tank to be in contact with the surface of the roller and to dissolve the sticky film. [0083] Stage No. 6: Depositing 100 l of solution on a suitable culture dish. [0084] Stage No. 7: Placing in an incubator at 36 C. overnight.

[0085] Counting the number of colonies on the culture dishes and comparing with the number of spores deposited on the surface.

[0086] In both cases, in connection with FIG. 3, no loss in collecting efficiency was observed, regardless of the storage period of the roller. This means that the roller, impregnated with the composition of the invention, has retained its tackiness over time. With regard to the spores, the roller has, for example, made it possible to collect 90% of the spores dispensed on a surface area of 2 m.sup.2, even after a storage period of 9 weeks.

[0087] The invention exhibits numerous advantages, among which are: [0088] the guarantee of preservation of the tackiness of the composition over time, even after a long storage period; [0089] ease of manufacture of the composition; [0090] 5-ease of use of the composition; [0091] obtaining a ready-to-use tool; [0092] the possibility of recovering all of the particles collected by the roller in the solution for dissolution of the gel.