Abstract
An adsorbent, a preparation method therefor and use thereof are provided. The adsorbent has a liquid channel, and the liquid channel has a low-tortuous porous structure. The adsorbent can realize fast and large-scale absorption of various liquids without consuming external energy and not requiring additional apparatuses when in use. The adsorbent can be used for efficient, safe and comfortable medical sampling and can also be used for recovery of various liquids.
Claims
1. An adsorbent, comprising a liquid channel having a low-tortuous porous structure.
2. The adsorbent according to claim 1, wherein the adsorbent is a sponge, the sponge comprises a framework consisting of porous filaments, a gap is provided between the porous filaments, the gap forms the liquid channel, and the gap between the porous filaments is of a low-tortuous porous structure.
3. The adsorbent according to claim 2, wherein the gap between the porous filaments is a 3D interconnected layered liquid channel and has a low-tortuous porous structure.
4. The adsorbent according to claim 2, wherein the framework has a multi-layer structure, each layer comprises a plurality of porous filaments arranged in parallel, the porous filaments between two adjacent layers are arranged in a staggered manner, a certain spacing distance is provided between adjacent filaments in each layer, a spacing distance may be provided or not provided between two adjacent layers, the spacing distance between two adjacent layers may be the same or different if provided, and the filaments are designed to form gaps having a 3D interconnected layered structure, i.e., the 3D interconnected layered liquid channels, and having a low-tortuous porous structure.
5. The adsorbent according to claim 1, wherein the filament has a diameter of about 100 m to 1200 m; and/or the liquid channel has a diameter of about 100 m to 2000 m.
6. A method for preparing the adsorbent according to claim 1, wherein the method comprises a following step: preparing the adsorbent by 3D printing.
7. The method according to claim 6, wherein the method specifically comprises: preparing a 3D printable ink; printing a layer body arranged in a filament shape by the 3D printable ink through a 3D printing device, wherein a gap is provided between filaments; then printing a second layer in a staggered manner, and so on to obtain the adsorbent.
8. Use of the adsorbent according to claim 1, wherein the adsorbent is used for medical sampling, or for treatment process after oil spilling, or for liquid collection.
9. A swab or cotton bud, wherein the swab or cotton bud has a tip provided with the adsorbent according to claim 1.
10. The swab or cotton bud according to claim 9, wherein the swab or cotton bud may be used for fast medical sampling, in particular as a nasopharyngeal swab for COVID-19 detection. Specifically, the swab or cotton bud may be used for sample collection in the post-COVID era, wherein the sample collection is efficient and comfortable.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0044] The drawings are included to provide a further understanding of the present disclosure, and are incorporated in and constitute a part of this specification. The components in the drawings are not necessarily to scale, but emphasize clearly illustrating principles of the embodiments of the present disclosure. The drawings illustrate the embodiments of the present disclosure and together with the description serve to explain the principles of the present disclosure.
[0045] FIGS. 1a and 1b provide schematic views of a liquid channel, wherein FIG. 1a represents a liquid channel having an interconnected cellular structure of the present disclosure, and FIG. 1B represents a liquid channel having a random structure in the prior art.
[0046] FIGS. 2a and 2b provide schematic diagrams of liquid absorption principle, wherein FIG. 2a represents the structure of the adsorbent of the present disclosure and its fast liquid absorption principle, and FIG. 2b represents an ice-templated sponge structure in the prior art and its slow liquid absorption principle.
[0047] FIGS. 3a, 3b, and 3c are functional relationship diagrams, wherein FIG. 3a shows viscosity of PU ink as a function of shear rate, FIG. 3b shows storage modulus (G) and loss modulus (G) of the PU ink as a function of strain, and FIG. 3c shows the measured length of the spacing distances and the filament diameter.
[0048] FIG. 4 shows a sample of an adsorbent having a large size of the present disclosure prepared by 3D printing.
[0049] FIG. 5 shows contact angles of different liquids on sponges of the present disclosure.
[0050] FIG. 6 shows the absorption of sponges with different pore structures of the present disclosure, wherein the absorption is tested with engine oil (having a viscosity of 214.5 mPa.Math.s and dyed in orange for easy to observe) as model liquid.
[0051] FIG. 7 shows the change in the height of the absorbed engine oil with time. These points are measured from experiments, while the solid line represents the fitted curve. The black dotted line is average height of the sponge. The 3D printed sponge showed a significant improvement in liquid absorption speed, and an increase in the spacing distances would further increase the speed.
[0052] FIG. 8 shows the absorption speed and absorption capacity of different sponges. All 3D printed sponges have similar absorption capacities, much larger than commercial sponges and ice-templated sponges.
[0053] FIG. 9 compares different sponges in terms of absorption speed, absorption capacity, density and porosity.
[0054] FIGS. 10a to 10h show the absorption properties of liquids having different viscosities, wherein FIG. 10a and FIG. 10b are methanol; FIG. 10c and FIG. 10d are isopropanol; FIG. 10e and FIG. 10f are liquid paraffin; and FIG. 10g and FIG. 10h are ethylene glycol. The insets in FIGS. 10a, 10c, 10e, and 10 g represent the liquid absorption at 3 s, 1 s, 14 s and 22 s for a commercial sponge (gray block), an ice-templated sponge (green block), and the 3D printed sponge of the present disclosure (red box), respectively.
[0055] FIG. 11 shows the cyclic absorption of the 3D printed sponge of the present disclosure for liquid paraffin.
[0056] FIG. 12 is a photograph of the 3D printed sponge of the present disclosure squeezed after 13 cycles.
[0057] FIG. 13 shows the requirements for a nasopharyngeal swab.
[0058] FIGS. 14a to 14d show the results of a comparison of a commercial cotton bud tip and a 3D printed cotton bud tip, and the bending and compression of the 3D printed cotton bud tip, wherein, FIG. 14a -shows a tip of a commercial cotton bud; FIG. 14b shows a 3D printed sponge of the present disclosure as a tip of a cotton bud; and FIG. 14c and FIG. 14d show the bending and compression of the 3D printed cotton bud.
[0059] FIG. 15 shows a cyclic compression test with increasing strain.
[0060] FIG. 16 shows the recovery of the 3D printed sponge of the present disclosure after the 7 .sup.th compression.
[0061] FIG. 17 shows the biocompatibility of the commercial swab and the 3D printed sponge swab of the present disclosure.
[0062] FIG. 18 shows the fast liquid collection of the 3D printed sponge swab of the present disclosure.
[0063] FIG. 19 shows that the 3D printed sponge swab of the present disclosure obtained a high efficiency liquid release capacity of sufficient sample.
DETAILED DESCRIPTION
[0064] Certain exemplary embodiments will now be described to provide an overall understanding of the structure, function, manufacture, and use principle of the adsorbent and method disclosed herein. One or more of these embodiments are illustrated in the drawings. Those skilled in the art will understand that the devices and methods specifically described herein and illustrated in the drawings are non-limiting exemplary embodiments. The features illustrated or described in connection with one exemplary embodiment may be combined with the features of other embodiments. Such modifications and variations are intended to be included within the scope of the present disclosure. Moreover, in the present disclosure, similarly-numbered components of various embodiments generally have similar features when those components have similar properties and/or serve similar purposes.
[0065] The present disclosure generally povid's a mechanism and method for preparing an adsorbent (specifically such as a sponge) for fast liquid absorption, and more particularly, an adsorbent that can be used for fast and comfortable sample collection in the post-COVID era as a medical swab or cotton bud.
[0066] As shown in FIG. 1a is an adsorbent having liquid channels with controllable channel size, low curvature and large porosity according to the present disclosure, which exhibits a high liquid absorption coefficient; and FIG. 1b is an adsorbent having random liquid channels in the prior art, due to the energy dissipation caused by friction, that is, the tortuous porous structure therein seriously impairs liquid absorption efficiency.
[0067] In FIGS. 2a and 2b, the unique pore structure and liquid absorption mechanism of the adsorbent of the present disclosure and the ice-templated sponge in the prior art are summarized. The ice-templated sponge having random channels in the prior art is directly freeze-dried to be used as a sample for standby comparison.
[0068] Based on the design in FIG. 1a and FIG. 2a, the sponge with the structure of the present disclosure is prepared by a 3D printing method, and then freeze-dried for 24 h. The method is specified as follows: [0069] 1) preparing a 3D printable ink; [0070] 2) based on the design in FIG. 1a and FIG. 2a, printing a layer body arranged in a filament shape by the 3D printable ink through a 3D printing device, wherein a gap is provided between filaments; then printing a second layer in a staggered manner, and so on; [0071] 3) freeze-drying after printing layer by layer to obtain the adsorbent (sponge) of the present disclosure. All sponges are made of the same 3D printable ink.
[0072] Specifically, the 3D printable ink includes a polymer, a thickening agent, a rheology modifier and a solvent.
[0073] Specifically, the solvent is selected from water, such as deionized water.
[0074] The thickening agent includes gelatin, hyaluronic acid, agarose or a mixture thereof. Specifically, the thickening agent is selected from hyaluronic acid.
[0075] The rheology modifier includes nanoclay, SiO2, alginate, Pluronic F-127, carbomer or a mixture thereof. Specifically, the rheology modifier is selected from nanoclay.
[0076] The polymer includes polyurethane, cellulose, alginate, polyvinyl alcohol, polyacrylamide or a mixture thereof. Specifically, the polymer is selected from polyurethane (PU).
[0077] The mass percentages of components in the 3D printable ink are as follows: 5%-60% of a polymer, illustratively 5%, 10%, 15%, 20%, 25%, 30%, 40%, 50%, 60%; 0%-10% of a thickening agent, illustratively 0%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%; 0%-10% of a rheology modifier, illustratively 0%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%; the balance of solvent.
[0078] As shown in FIGS. 1a-1b and FIG. 2a-2b, the 3D printed sponge of the present disclosure showed well-structured (low-tortuous porous structure), which comprising porous framework and 3D interconnected layered liquid channels, whereas only random pore structure is observed in the ice-templated sponge.
[0079] As shown in FIGS. 3a-3c, the 3D printable PU ink of the present disclosure showed shear-thinning properties. After squeezed from a nozzle, the uniform distribution of the printed filaments showed excellent shape fidelity.
[0080] As shown in FIG. 4, the large-size sponge can be prepared by a 3D printing method using the PU ink, which showed excellent 3D printability and great potential in real product manufacturing.
[0081] As shown in FIG. 5, the sponge of the present disclosure showed good wettability to various liquids. In the detailed description of the exemplary embodiments, methanol, isopropyl alcohol, liquid paraffin, ethylene glycol and engine oil are used for test wettability. Illustratively, in the sponge, the polymer is polyurethane with a mass fraction of 10%; the thickening agent is hyaluronic acid with a mass fraction of 2%; the rheology modifier is nanoclay with a mass fraction of 4%; and the balance is deionized water.
[0082] As shown in FIG. 6, the sponge having specific liquid channels of the present disclosure showed a faster liquid absorption than the sponge having random channels in the prior art. In the detailed description of the exemplary embodiments, engine oil is used as the test liquid. Illustratively, in the sponge, the polymer is polyurethane with a mass fraction of 10%; the thickening agent is hyaluronic acid with a mass fraction of 2%; the rheology modifier is nanoclay with a mass fraction of 4%; and the balance is deionized water. 1 mm, 1.3 mm and 1.6 mm are selected as the print spacing distance.
[0083] As shown in FIG. 7 and FIG. 8, the 3D printed sponge of the present disclosure showed a faster liquid absorption capacity compared to the commercial sponge and the ice-templated sponge. Specifically, FIG. 7 shows the change in the height of the absorbed oil with time. These points are measured from experiments, while the solid line represents the fitted curve. The black dotted line is average height of the sponge. The 3D printed sponge of the present disclosure showed a significant improvement in liquid absorption speed, and it can be seen that a larger spacing distance (i.e., channel diameter) would lead to a faster absorption speed. Illustratively, in the sponge, the polymer is polyurethane with a mass fraction of 10%; the thickening agent is hyaluronic acid with a mass fraction of 2%; the rheology modifier is nanoclay with a mass fraction of 4%; and the balance is deionized water. FIG. 8 shows the absorption speed and absorption capacity of different sponges. All 3D printed sponges have similar absorption capacities, much larger than commercial sponges and ice-templated sponges. Illustratively, in the 3D printed sponge, the polymer is polyurethane with a mass fraction of 10%; the thickening agent is hyaluronic acid with a mass fraction of 2%; the rheology modifier is nanoclay with a mass fraction of 4%; and the balance is deionized water.
[0084] As shown in FIG. 9, the 3D printed sponge of the present disclosure, especially the sponge with a spacing distance of 1.6 mm, has the characteristics of high liquid absorption speed, large absorption capacity, high porosity, low density and the like. Illustratively, in the 3D printed sponge, the polymer is polyurethane with a mass fraction of 10%; the thickening agent is hyaluronic acid with a mass fraction of 2%; the rheology modifier is nanoclay with a mass fraction of 4%; and the balance is deionized water.
[0085] FIGS. 10a-10h show the fast absorption mechanism of the 3D interconnected liquid channels of the present disclosure, and the adsorbent of the present disclosure can be applied to various liquids. In the detailed description of the exemplary embodiments, methanol, isopropanol, liquid paraffin and ethylene glycol are selected as the liquid to test the absorption property; FIG. 10a and FIG. 10b are methanol; FIG. 10c and FIG. 10d are isopropanol; FIG. 10e and FIG. 1 if are liquid paraffin; and FIG. 10g and FIG. 10h are ethylene glycol. The insets in FIG. 10a, FIG. 10c, FIG. 10e, and FIG. 10g represent the liquid absorption at 3 s, 1 s, 14 s and 22 s for a commercial sponge (gray block), an ice-templated sponge (green block), and the 3D printed sponge of the present disclosure (red box), respectively. As shown in FIGS. 10a-10h, the above four liquids all showed excellent absorption capacity. The 3D printed sponge is made of the same material as the ice-templated sponge. Illustratively, in the 3D printed sponge and the ice-templated sponge, the polymer is polyurethane with a mass fraction of 10%; the thickening agent is hyaluronic acid with a mass fraction of 2%; the rheology modifier is nanoclay with a mass fraction of 4%; and the balance is deionized water.
[0086] FIG. 11 shows the cyclic absorption of the 3D printed sponge of the present disclosure for liquid paraffin. FIG. 12 is an optical image of the 3D printed sponge of the present disclosure squeezed after 13 cycles. As shown in FIG. 11 and FIG. 12, the 3D printed sponge of the present disclosure showed good reusability and stability even after multiple squeeze-absorption cycles. Illustratively, in the 3D printed sponge, the polymer is polyurethane with a mass fraction of 10%; the thickening agent is hyaluronic acid with a mass fraction of 2%; the rheology modifier is nanoclay with a mass fraction of 4%; and the balance is deionized water.
[0087] FIG. 13 shows the requirements for a nasopharyngeal swab. As shown in FIG. 13, a nasopharyngeal swab is inserted into the nostril to capture nasopharyngeal secretions. In the detailed description of the exemplary embodiments, a swab tip with large liquid capturing and releasing capacity is preferred for accurate diagnosis. Furthermore, biosafety and soft mechanical properties are also necessary to improve patient satisfaction.
[0088] FIGS. 14a-14d show the results of a comparison of a commercial cotton bud tip and the 3D printed cotton bud tip of the present disclosure, and the bending and compression of the 3D printed cotton bud of the present disclosure; wherein, FIG. 14a shows a tip of a commercial cotton bud; FIG. 14b shows a 3D printed sponge of the present disclosure as a tip of a cotton bud; and FIG. 14c and FIG. 14d show the bending and compression of the 3D-printed cotton bud of the present disclosure. As shown in FIGS. 14a-14d, the 3D printed cotton bud tip of the present disclosure is flexible and can be allowed to be bent and compressed; and the soft 3D printed cotton bud can greatly reduce pain, sneezing and nausea during high frequency testing of patients. Illustratively, in the 3D printed cotton bud, the polymer is polyurethane with a mass fraction of 10%; the thickening agent is hyaluronic acid with a mass fraction of 2%; the rheology modifier is nanoclay with a mass fraction of 4%; and the balance is deionized water.
[0089] FIGS. 15 and 16 show the results of cyclic compression testing of the incremental strain of the adsorbent of the present disclosure. As shown in FIGS. 15 and 16, the 3D printed sponge of the present disclosure recovered well after 7 cycles with a compressive strain as high as 70%. Illustratively, in the 3D printed sponge, the polymer is polyurethane with a mass fraction of 10%; the thickening agent is hyaluronic acid with a mass fraction of 2%; the rheology modifier is nanoclay with a mass fraction of 4%; and the balance is deionized water.
[0090] As shown in FIG. 17, the 3D printed sponge of the present disclosure showed excellent biocompatibility. After 24 hours of co-culture of MHCC97-L cells with the 3D printed sponge of the present disclosure, the cells obtained a survival rate of 92.6%, indicating that the 3D printed sponge of the present disclosure does not cause any cytotoxic effect. Illustratively, in the 3D printed sponge, the polymer is polyurethane with a mass fraction of 10%; the thickening agent is hyaluronic acid with a mass fraction of 2%; the rheology modifier is nanoclay with a mass fraction of 4%; and the balance is deionized water.
[0091] As shown in FIG. 18, it takes only 5.5 seconds for the tip of the 3D printed swab of the present disclosure to absorb 100 L of liquid, whereas the tip of existing commercial swab cannot absorb such a large amount of liquid. Illustratively, in the 3D printed swab, the polymer is polyurethane with a mass fraction of 10%; the thickening agent is hyaluronic acid with a mass fraction of 2%; the rheology modifier is nanoclay with a mass fraction of 4%; and the balance is deionized water.
[0092] As shown in FIG. 19, the 3D printed swab solution of the present disclosure showed a darker color after the absorbed sample was released into a vial, indicating that the sample with a higher concentration was obtained. The fast liquid absorption and efficient release enable 3D printed swabs to collect higher concentration of samples in a shorter time than existing commercial swabs, thereby enabling fast and accurate diagnosis. Illustratively, in the 3D printed swab, the polymer is polyurethane with a mass fraction of 10%; the thickening agent is hyaluronic acid with a mass fraction of 2%; the rheology modifier is nanoclay with a mass fraction of 4%; and the balance is deionized water.
[0093] In summary, the present disclosure provides a sponge having a special liquid channel, which can achieve fast liquid absorption and shows potential applications of low cost, fast and comfortable medical sample collection in the post-COVID era.
[0094] The aforementioned description of the present disclosure is provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the present disclosure to the precise form disclosed. Many modifications and variations will be apparent to those skilled in the art.
[0095] These embodiments are chosen and described in order to better explain the principles of the present disclosure and its practical applications, to thereby enable others skilled in the art to understand the various embodiments of the present disclosure and the various modifications as are suited to the particular use contemplated. It is intended that the scope of the present disclosure and its equivalents be defined by the following claims.
