Wall covering composition for green walls

Abstract

The present disclosure concerns dry formulations that are based on oil shale ash and further contain viable materials in dried form, and slurry composition prepared therefrom for forming a wall covering composition for promoting vegetative growth onto a wall. The disclosure further concerns kits and methods for forming such compositions.

Description

[0001] Wall covering composition for green walls

[0002] TECHNOLOGICAL FIELD

[0003] The present disclosure concerns compositions for green walls. More particularly, the disclosure concerns wall covering compositions that promote growth of plants.

[0004] BACKGROUND ART

[0005] References considered to be relevant as background to the presently disclosed subject matter are listed below:

[0006] - CN106146191

[0007] - CN104140305

[0008] - CN103992174

[0009] - CN106431631

[0010] - US2016 / 0219810

[0011] - JP2004261131

[0012] Acknowledgement of the above references herein is not to be inferred as meaning that these are in any way relevant to the patentability of the presently disclosed subject matter.

[0013] BACKGROUND

[0014] Green walls, namely vertical surfaces onto which vegetation is grown, have recently become popular both for indoor and outdoor wall surfaces. In most cases, a hardware infrastructure that includes a support surface or webbing and irrigation systems is required, into which seedlings or fully-developed plants are incorporated.

[0015] In other arrangements, hydroponic systems are used, typically including an array of tubing elements, through which water with nutrients is circulated. Plants are held within openings in the tubing, permitting the roots of the plants to be submerged in water, hence facilitating growth of the plants without soil or a fixed bed. In both cases, covering the wall with vegetation requires complex and, most often expensive, construction of structural elements onto the wall.

[0016] GENERAL DESCRIPTION

[0017] The present disclosure provides a composition for wall covering that promotes and supports vegetation growth thereonto. In other words, the compositions of this disclosure are designed for painting or plastering over the wall, and include nutrients and viable vegetative materials, such that once applied onto the wall surface, the viable vegetative materials grow to cover the wall after a defined period of time.

[0018] The compositions are based on a dry formulation that contains the viable vegetative materials in dried form, and is formulated to be suitable for mixing with an aqueous liquid, to form a slurry or a paste that can be applied directly onto wall surfaces or over a suitable primer composition applied on a wall surface. Hence, the compositions of this disclosure have good adherence to vertical walls, and can be applied in similar techniques to plaster, render, Tyrolean finish, etc. - namely by spraying or by trowel application.

[0019] Accordingly, in one of its aspects, the disclosure provides a dry formulation for forming a wall covering composition for promoting vegetative growth onto a wall, the formulation comprising: at least about 40 wt% oil shale ash, at least one binder, at least one hygroscopic filler in particulate form, and at least about 5 wt% of at least one viable material in dried form.

[0020] As used herein, the term formulation means to denote a dry mixture, typically having a particulate form, while the term composition denotes a mixture of the formulation and an aqueous liquid (e.g. water) to form a slurry that is suitable for application onto the wall surface.

[0021] A main component of the formulation of this disclosure is oil shale ash which is a waste product resulting from burning of oil shale. Oil shale is a sedimentary deposit that contains kerogen, from which liquid hydrocarbons can be produced. Typically, once the kerogen and other carbonaceous components (such as bitumen) are removed or extracted, the spent oil shale is thermally treated to remove the residual organic materials and / or char, to result in oil shale ash. The oil shale ash is in the form of porous particles, containing predominantly inorganic materials, typically silica (silicon dioxide, SiCh), and various trace metals and elements (such as calcium, iron, sulfur, phosphorus, magnesium, potassium, sodium, and others). The porous nature of the oil shale ash can function to retain water, hence maintaining a hydrated environment for the sprouting and growing of vegetation from the plant-part in viable dried form, while the trace metals and elements provide required nutrients and minerals to the growing vegetation.

[0022] According to some embodiments, the formulation comprises between about 40 wt% and 80 wt% of said oil shale ash. In some embodiments, 40 wt% and 70 wt% of said oil shale ash. According to some embodiments, the formulation comprises between about According to some embodiments, the formulation comprises about 40 wt%, about 45 wt%, about 50 wt%, about 55 wt%, about 60 wt%, about 65 wt%, about 70 wt%, or even about 80 wt% of said oil shale ash

[0023] According to some embodiments, the oil shale ash used in the formulation has a particle size of at most about 5 mm (millimeters), typically no more than 3 mm. Such particle size renders the slurry composition prepared from the dry formulation suitable for application onto wall surfaces by standard techniques.

[0024] As noted, the formulations contain at least one viable material in dried form. Within the context of the present disclosure, the term viable material in dried form refers to a part of an organism that contains reproductive organs or organelles, and is capable of surviving when in a dry state, to germinate or sprout after hydration. In other words, the viable material is incorporated in its dried form into the formulation, and maintained dormant while the formulation is kept in its dry form. Once mixed with water to form a composition applicable onto walls, the dried viable material is hydrated, promoting germinating, sprouting and proliferation of a living organism.

[0025] Depending on the environmental conditions to which the composition will be exposed to after application (namely climatic conditions such as temperature range, exposure to sun, relative humidity, type and amount of atmospheric precipitation, air salinity, etcf the viable material can be selected to be suitable for proliferation under such conditions.

[0026] According to some embodiments, the viable material is derived from at least one plant, at least one lichen, at least one alga, and at least one fungus - and, accordingly, the living organism can be a plant, a lichen, algae, or a fungus. By some embodiments, the at least one viable material in dried form is selected from spore-containing dried moss, lichen, fungal spores, mycelium, algae spores, and seeds.

[0027] Particularly suitable for low-maintenance green walls are various mosses, lichen, and fungi, that can proliferate and thrive under minimal irrigation conditions and minimal care. For walls that also include irrigation systems, plant seeds and algae spores can also be incorporated.

[0028] According to some embodiments, the formulation comprises between about 5 wt% and about 20 wt% of said at least one viable material in dried form.

[0029] For forming a paste or slurry that holds the oil shale ash and viable material in dried form together when mixed with water, the formulation comprises at least one binder. The binder is typically at least one polymeric material, that is water soluble and / or water dispersible, capable of emulsifying in water, or forms a hydrogel once mixed with water, thereby forming a substantially continuous matrix in which the particles of the oil shale ash and the viable material are at least partially embedded.

[0030] By some embodiments, the formulation comprises between about 15 wt% and about 40 wt% of said at least one binder, typically between about 20 wt% and about 40 wt% of said binder.

[0031] According to some embodiments, the at least one binder is selected from vinyl acetate acrylic copolymer, acrylic copolymers, vinyl alcohol polymers, vinyl acetate copolymers, vinyl alcohol - vinyl acetate copolymers, polyvinyl chloride and copolymers thereof, polyurethanes, and mixtures thereof.

[0032] The formulation also comprises one or more fillers, that are selected to provide the slurry or paste, formed from the formulation when wetted, with a desired consistency that is suitable for application onto the wall surface. The fillers are hygroscopic, namely are capable of absorbing and retaining water or moisture, and are typically inorganic materials. In combination with the binder, the one or more fillers provide mechanical and dimensional stability of the composition once applied onto the wall surface, to thereby form a composition that is capable of adhering to and covering of the wall surface.

[0033] By some embodiments, the formulation comprises between about 1 wt% and about 15 wt% of said at least one hygroscopic filler. By some embodiments, the at least one hygroscopic filler is a metal oxide, metal hydroxide or a silicate, for example silica, fumed silica, alumina, alumina silicate, aluminum oxide hydroxide, zeolites, etc.

[0034] The formulation can further comprise, according to some embodiments, at least one pH modifier, for adjusting the pH to a suitable pH value for supporting and sustaining germination of the viable material after wetting.

[0035] By some embodiments, the formulation comprises between about 1 wt% and about 5 wt% of said at least one pH modifier.

[0036] By some embodiments, the formulation can further comprise at least one surfactant, e.g. for facilitating dispersion of the fillers and / or the binders into the slurry one the formulation is mixed with water. By some embodiments, the formulation comprises between about 1 wt% and about 5 wt% of surfactants.

[0037] According to some embodiments, the formulation can further comprise at least one fertilizing or nutrient, which can be organic or inorganic. The fertilizers and / or nutrients added to the formulation (namely nutrients beyond those contained in the oil shale ash) are typically tailored to the type of viable material, and can be tailored according to the environment in which the composition is applied.

[0038] In some embodiments, the formulation further comprises at least one functional additive to provide the formulation or the composition produced therefrom with one or more desired properties. Such functional additives can be any one or more of foaming agents, de-foaming agents, UV-stabilizers, rheologic modifier, anti-caking agents, etc.

[0039] By another of its aspects, the present disclosure provides a wall covering composition for promoting vegetative growth onto a wall surface, the composition comprising: the dry formulation as disclosed herein; and an aqueous liquid.

[0040] The term aqueous liquid means to denote a liquid that comprises predominantly water (e.g. at least 80 wt% water). According to some embodiments, the aqueous liquid is water.

[0041] By some embodiments, the aqueous liquid comprises one or more of a fertilizer, a pH modifier, a foaming agent, and a de-foaming agent. Depending on the amount of water in the composition, the wall covering composition can be tailored for application in various techniques, such as brushing, smearing, pasting, spraying, etc.

[0042] In some embodiments, the composition comprises at least 1 part aqueous liquid to 1 part of said binder. In other words, the composition comprises at least the same weight percentage of the aqueous liquid in the composition as the weight percentage of binder in the dry formulation.

[0043] In some embodiments, the composition comprises between about 1.25 parts and about 2 parts aqueous liquid to 1 part of said binder, and the composition has a paste consistency.

[0044] In some other embodiments, the composition comprises between about 2 parts and about 4 parts aqueous liquid to 1 part of said binder, and the composition has a sprayable consistency.

[0045] In order to maintain suitable activity conditions for promoting germination of the viable material and / or support proliferation of the living organism, the wall covering composition can have, by some embodiments, a pH value of between about 5 and about 8.

[0046] According to another aspect, there is provided a process for preparing a composition disclosed herein, the process comprises mixing the formulation according to this disclosure with said aqueous liquid.

[0047] Mixing is typically carried out prior to application onto the wall, namely up to a few hours prior to application, preferably immediately prior to application.

[0048] Mixing can be carried out in any suitable vessel, for example a mixing tank, a rotating drum, etc. The vessel can optionally be equipped with one or more agitators, mixing paddles, baffles, flow diverters, etc.

[0049] By some embodiments, the formulation is mixed with water for a period of time of between about 10 and about 60 minutes.

[0050] By some embodiments, the process can further comprise mixing at least one fertilizer or nutrient into the composition.

[0051] By other embodiments, the process can further comprise mixing at least one fertilizer or nutrient into the water prior to mixing with the formulation. By some other embodiments, the process can further comprise mixing at least one fertilizer or nutrient into the formulation prior to mixing with water.

[0052] By some embodiments, the process can further comprise mixing at least one fertilizer or nutrient concomitant with mixing said formulation with water.

[0053] By another aspect, the disclosure provides a kit comprising a dry formulation as disclosed herein, and one or more fertilizers and / or nutrients.

[0054] In some embodiments, the fertilizers and / or nutrients can be provided in a single dose form, suitable for mixing with the formulation before mixing with water to form a batch of the composition. Alternatively, the fertilizers and / or nutrients can be mixed or solubilized into the required quantity of water, and then mixed with the formulation to form the slurry composition. The single dose form can be a single-use container, a singleuse bag, a single-use sachet, a single dose pressed pellet or tablet, or any other suitable single dose form.

[0055] In other embodiments, the fertilizers and / or nutrients can be provided in a multidose form, e.g. a bulk container or a plurality of single-dose units, that contains several doses of the fertilizers and / or nutrients. In such embodiments, a first dose of fertilizers and / or nutrients can be mixed into the formulation or into water before mixing water and the formulation to form the composition, and the remaining doses can be used for addition into irrigation water at a later stage for providing nutrients and / or fertilizers to the germinating or growing plants, fungi, algae, lichen, etc.

[0056] By some embodiments, the kit can comprise at least two types of fertilizers and / or nutrients, a first of which being tailored for the germination stage of the viable material, and a second of which being suitable to promote growth after germination.

[0057] Depending on the construction material of the wall, the type of finishing of the surface onto which the composition is to be applied, and / or the environmental conditions to which the wall is exposed, there may be a need for priming the surface of the wall prior to application of a composition of this disclosure. Thus, by another aspect, the disclosure provides a kit that comprises a formulation as disclosed herein, and a primer composition.

[0058] The primer composition is formulated to improve adhesion of the composition of this disclosure onto the wall, and can be selected according to the construction material of the wall, the type of finishing of the surface onto which the composition is to be applied, and / or the environmental conditions to which the wall is exposed. Thus, different kits that include different primers can be provided, depending on the specific application conditions of the composition.

[0059] By another aspect, there is provided a method for forming vegetative cover over at least a portion of a wall surface, the method comprising: applying a composition as disclosed herein over said wall surface, permitting the composition to dry to obtained a covered wall surface, and periodically irrigating the covered wall surface for a predefined period of time to permit germination of said viable material.

[0060] By some embodiments, said predefined period of time is between about 7 days and about 4 months.

[0061] According to some embodiments, said portion of wall surface can be the entire surface of the wall.

[0062] By other embodiments, said composition is applied onto a plurality of surface portions. The plurality of surface portions can be randomly distributed onto the wall surface, arranged in an array, or form a defined pattern onto the wall - such as an image, lettering, numbering, etc.

[0063] Applying the composition onto the wall surface can be carried out in any suitable technique, for example spraying, plastering, smearing, brushing, etc.

[0064] According to some embodiments, the composition is permitted to dry over the wall for a period of time of at least 1 hour, e.g. at least 2, 3, 4, 5 ,6 hours or even more, depending, inter alia, on the amount of water in the composition, the surrounding moisture level, exposure to sunshine or a heat source, etc.

[0065] Depending on the viable material and the living organism to be obtained therefrom, as well as depending on the environmental conditions to which the composition is exposed after application onto the wall, irrigation can be done on a daily basis, every few days, once a week, twice a month, once a month, etc.

[0066] Further, depending on the viable material and the living organism to be obtained therefrom, irrigation can be carried out by spraying, misting, drip irrigation, direct irrigation, or any other suitable irrigation means. As used herein, the singular form a, an and the include plural references unless the context clearly dictates otherwise. For example, the term "a binder" or "at least one binder" may independently include a plurality of binders, including mixtures thereof.

[0067] As used herein, the term about is meant to encompass deviation of ±10% from the specifically mentioned value of a parameter, such as concentration, weight ratio, viscosity, etc.

[0068] Whenever a numerical range is indicated herein, it is meant to include any cited numeral (fractional or integral) within the indicated range. The phrases ranging / ranges between a first indicate number and a second indicate number and between a first indicate number and a second indicate number are used herein interchangeably and are meant to include the first and second indicated numbers and all the fractional and integral numerals therebetween.

[0069] Throughout this disclosure, unless the context requires otherwise, the word comprise, and variations such as comprises and comprising, will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any integer or step or group of integers and steps.

[0070] Generally it is noted that the term ...at least one... as applied to any component of a formulation or a composition of this disclosure should be read to encompass one, two, three, four, five, or more different occurrences of said component in a formulation or a composition disclosed herein.

[0071] It is appreciated that certain features of the disclosure, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the disclosure, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination or as suitable in any other described embodiment of the disclosure. Certain features described in the context of various embodiments are not to be considered essential features of those embodiments, unless the embodiment is inoperative without those elements.

[0072] BRIEF DESCRIPTION OF THE DRAWINGS

[0073] In order to better understand the subject matter that is disclosed herein and to exemplify how it may be carried out in practice, embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:

[0074] Fig i shows the effect of oil shale ash addition on Romain lettuce growth, average fresh mass on day 41.

[0075] Fig. 2 shows the effect of oil shale ash addition on Romain lettuce growth, average dry mass on day 41.

[0076] Figs. 3A-3B are pictures of paste compositions applied over wall segments, prepared from dry formulations.

[0077] DETAILED DESCRIPTION OF EMBODIMENTS

[0078] Example 1 - Profile of oil shale ash nutrients

[0079] In order to assess the suitability of oil shale ash to provide essential nutrients to vegetative matter, an elemental analysis by inductive coupled plasma (according to European standard EP A 6010D) was carried out for a sample of oil shale ash, particle size 7mm. The results are provided in Table 1.

[0080] Table 1: Elemental analysis of oil shale As can be seen, oil shale ash is rich in essential elements, such as calcium, iron, magnesium, phosphorous, potassium, sodium, and sulfur, all essential for proper development of vegetative matter. Further, it was found that oil shale ash contains significant amounts of other elements considered to be beneficial for vegetal growth, including copper, manganese, molybdenum, nickel and zinc.

[0081] In a separate leaching test according to international standard EN-12457-2 carried onto the same samples, the release of hazardous elements into water. The results are provided in Table 2.

[0082] Table 2: Leaching test

[0083] Hence, a can be seen, oil shale ash contains significant amounts of nutrients, while demonstrates negligible leaching of hazardous elements into water. This was found to make oil shale ash particularly suitable as a nutrient source for vegetative material.

[0084] Example 2 - Utilization of oil shale ash as nutrients supplemental material

[0085] In order to assess the general beneficial effect of oil shale ash on vegetative growth, commercial organic compost was enriched with 20 vol% of oil shale ash. Then, 5 wt%, 10 wt% and 20 wt% of enriched compost was mixed with standard growing substrate.

[0086] Another type of growing substrate was prepared by mixing 5 wt%, 10 wt% and 20 wt% of the commercial compost, not enriched with oil shale ash.

[0087] Romain lettuce seedlings were planted in the several groups of growing substrate: Group 1 was grown on the growing substrate with commercial compost, Group 2 was grown using soil containing the enriched compost, and Group 3 was grown on noncomposted soil. All other growing conditions (e.g. irrigation regimen, exposure to light, etc.) were kept identical for all groups. On day 41 the plants were harvested and the weight and dry weight of the plants were measured. The test results are provided in Figs. 1 and 2, respectively.

[0088] As can be seen, in particular for Group 2, the plants which were grown on 10-20 wt% enriched compost have significant increase in both fresh and dry mass, as compared to the non-enrich compost used for Group 1.

[0089] This attest to the ability of the oil shale ash to function as an efficient fertilizer for growing vegetative material.

[0090] Example 3 - Utilizing oil shale ash in formulation for forming a wall covering composition for promoting vegetative growth

[0091] The oil shale ash was used to prepare dry formulations for forming a wall covering composition for promoting vegetative growth, that can be applied onto walls. The dry formulations were prepared by mixing the ingredients. At least 5 wt% moss spores are then incorporated into the dry formulation (based on the total weight of the formulation). Table 3 presents some of the tested formulations.

[0092] Once dry formulations were prepared, the formulations were mixed with water (150-200% from the binder weight) in order to form viscous paste-like wall covering composition, which were then applied onto standard concrete walls by plastering.

[0093] For a composition prepared from Formulation 1, it was found that high concentrations of binder caused difficulties in applying the paste composition onto the wall surface, resulting in uneven adhesion and formation of undesired air bubbles (Fig. 3B). For lower amounts of binder such as those of Formulations 2 and 3, however, significantly easier application was observed, forming relatively smoother surface and even coverage (Fig. 3 A), it was also found that below 10 wt% binder, the dried compositions prepared therefrom were insufficiently cohesive, and demonstrated mechanical disintegration. Table 3: Tested dry formulations (wt%)

[0094] The formulations are then left to dry and permit the viable vegetative materials, in this case moss, to grow to cover the wall.

Claims

CLAIMS:

1. A dry formulation for forming a wall covering composition for promoting vegetative growth onto a wall, the formulation comprising: at least about 40 wt% oil shale ash, at least one binder, at least one hygroscopic filler in particulate form, and at least about 5 wt% of at least viable material in dried form.

2. The formulation of claim 1, comprising between about 40 wt% and 80 wt% of said oil shale ash.

3. The formulation of claim 1 or 2, wherein said oil shale ash having a particle size of at most about 5 mm.

4. The formulation of any one of claims 1 to 3, comprising between about 5 wt% and about 20 wt% of said at least one viable material in dried form.

5. The formulation of any one of claims 1 to 4, wherein said at least one viable material is derived from at least one plant, at least one lichen, at least one algae, or at least one fungus.

6. The formulation of any one of claims 1 to 4, wherein said at least one viable material in dried form is selected from spore-containing dried moss, lichen, fungal spores, mycelium, algae spores, and seeds.

7. The formulation of any one of claims 1 to 6, comprising between about 15 wt% and about 30 wt% of said at least one binder.

8. The formulation of any one of claims 1 to 7, wherein said at least one binder is at least one polymeric material.

9. The formulation of claim 8, wherein said polymeric material is selected from vinyl acetate acrylic copolymer, acrylic copolymers, vinyl alcohol polymers, vinyl acetate copolymers, vinyl alcohol - vinyl acetate copolymers, polyurethanes, and mixtures thereof.

10. The formulation of any one of claims 1 to 9, comprising between about 1 wt% and about 15 wt% of said at least one hygroscopic filler.

11. The formulation of any one of claims 1 to 10, wherein said at least one hygroscopic filler at least one inorganic hygroscopic filler.

12. The formulation of claim 10 or 11, wherein said at least one hygroscopic filler is selected from a metal oxide, metal hydroxide, a silicate and mixtures thereof.

13. The formulation of any one of claims 1 to 12, further comprising at least one pH modifier.

14. The formulation of claim 13, comprising between about 1 wt% and about 5 wt% of said at least one pH modifier.

15. The formulation of any one of claims 1 to 14, further comprising at least one surfactant.

16. The formulation of any one of claims 1 to 15, further comprising at least one foaming agent.

17. The formulation of any one of claims 1 to 16, further comprising at least one fertilizing or nutrient.

18. A wall covering composition for promoting vegetative growth onto a wall, the composition comprising: a formulation according to any one of claims 1 to 17; and an aqueous liquid.

19. The wall covering composition of claim 18, wherein said aqueous liquid is water.

20. The wall covering composition of claim 18 or 19, having a pH value of between about 5 and about 8.

21. The wall covering composition of any one of claims 18 to 20, wherein the composition comprises at least 1 part aqueous liquid to 1 part of said binder.

22. The wall covering composition of claim 21, wherein the composition comprises between about 1.25 parts and about 2 parts aqueous liquid to 1 part of said binder, and the composition has a paste consistency.

23. The wall covering composition of claim 21, wherein the composition comprises between about 2 parts and about 4 parts aqueous liquid to 1 part of said binder, and the composition has a sprayable consistency.

24. A kit comprising: a formulation according to any one of claims 1 to 17; and one or more fertilizers and / or nutrients.

25. A kit comprising: a formulation according to any one of claims 1 to 17; and a primer composition.

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