Halogen-substituted silane means a silane molecule containing silicon (Si) atom(s) covalently bound with 1, 2, 3 or 4 of any of the halogen-elements from the Periodic Table such as Chlorine (Cl), Fluorine (F), Iodine (I) and Bromine (Br) at a particular single silicone atom—a minimum of one and more (up to all) silicon atom(s) may be bound to halogen atom(s). Within the description of this invention as required by the chemical principles, a maximum of 4 halogen atoms are allowed to be covalently bound at each one silicone (Si) atom therefore the total number of halogen-atoms within a silane molecule may be higher than 4; i.e. depending upon the total number of silicone atoms within the particular silane molecule of choice and the molecular structure of the molecule. The same requirements are valid for the carbon atom within carbon-silanes, hydrocarbons and their chemical derivatives—i.e. halogenated carbons and halogenated carbon-silanes (carbo-silanes).
Silane in general means any substance with molecule containing at least one silicone (Si) atom. The description “silicones” for the whole class of polysiloxanes is an imitation of the oxygen-carbon bonds of carbon chemistry which are known as “ketones”. (The latter however, because of their particular characteristics, form double bonds instead of single bonds)
Nanolayer and microlayer: The words “nano” and “micro” refer to the metric scale of measurements as defined by the international SI system. In more general meaning for the purpose of this invention the “nanolayer” and “microlayer” are used to as to refer to a very thin surface layer composed by molecular-size components—usually not exceeding microns-size thicknesses.
All chemical terminology used is according to the widest-possible meaning as accepted within the common chemical practice and terminology and closely matches the UPAC nomenclature.
This invention relates to thin-layer coating compositions which have high application flexibility, relatively low toxicity, produces a highly durable solids- and semi-solids coating, and has an improved external appearance, curability, and long-lasting properties achieved by permanent-type bonding. More particularly, the invention relates to a curing composition useful as a finishing coating composition for surface-deposition and -derivatization with highly active chemical groups serving for subsequent substitution and attachment of desired chemical, bio-chemical and nano-sized solids thereby serving as a bonding agents to metal, plastic and biological surfaces, glass surfaces, and used in applicable fields including but not limited to biological objects, bio-array preparation technology, 3-dimensional micro-casting and material encapsulation for phase separation or surface derivatization, and for designing optical properties such as but not limited to light-channeling micro-fiber affects and cloaking effects.
In the past 20-30 yeas silane chemistry is one of the highly developing areas of the modern chemical industry applicable to wide areas of world economy—from fundamental chemistry and construction industry to microelectronics and bio-microarray technology. As a result extremely wide varieties of silane- and carbon-silane chemicals have been produced serving for wide variety of purposes and applications. Many of them are used for the preparation of different repellant surfaces, generally—water- or oil-repellant. Variety of patents has been filed to support such discoveries. Nevertheless, universal approach has been to produce silane-containing compounds including single-type silanes or silane-containing substances exhibiting both certain desired physical- and chemical properties, and different levels of chemical structure complexity. For example almost any sealant or paint product includes cyclic silanes as additives—used as a repellant—or shine contributor; which, however, are (as is) incapable of creating effective nano-layers when not cross-reacted with other—chemically-active silane(s). Although this common type of approach had successfully resulted in the global development of silane chemistry and industry, producing inexpensive compounds with complex and efficient properties for use in wide variety of applications could be achieved by a novel, very flexible, easy and low-cost approach of combining (mixing) two or more silane-containing chemicals capable of pre-and/or post-reacting with each-other and/or with the target surfaces upon their final application. This approach of “assembling properties” in situ by combining multiple silane- (alone) and multiple silane- & non-silane chemicals, rather than “designing & chemically synthesizing” specialized chemical substances (silanes), is extremely benefiting from any point of view.
The invention describes methodological approach for preparation and utilization of variable compositions of one-, two- and multi-component solutions containing variety of halogenated silanes, cyclic molecular compounds (silanes, hydrocarbons, silane-carbons and their derivatives) and other hydrophobic or hydrophilic molecular components (in a form of separate molecular substances or as molecular substitutes within the silanes and/or the cyclic compound molecules).
The essential parts of this invention are:
Such methodological approach offers better flexibility for surface attachment and encapsulation, water-affinity or hydrophobic properties, durability and long-lasting (permanent) bonding for specific surface applications and for preparation of other subsequent types of repellant- or affine surfacing solutions such as paints or sealing agents, textiles and else.
In the drawings, which form a part of this specification, are presented in the following:
The present invention will be described in further detail herein below.
The invented approach explores the ability of single-, double- and multi-halogen-element-substituted (shortly: “halogen-substituted”) silanes and silanes with highly reactive chemical groups such as azido-, acetylene-, mercapto-, sulfonate-, thiol-, methoxy-, methacryloxy-, and else (including, but not limited only to, any alkyl-, aryl- and cyclic-silanes) to form both: poly-condensates (carrying certain quantities of repellant chemical groups) with other chemicals (silanes, organosilanes, carbohydrates, etc.) and to form violently-fast covalent bonds with almost any surface molecules of the substances applied on/to (because of the high reactivity of the halogen atoms) resulting in the formation of 2- or 3-dimensional nano-layers exhibiting designed-level of hydrophilic-, hydrophobic or bi-polar properties depending upon the type and the position of molecular substitutes chosen within the silane molecules. The absorption (adherence) capabilities of the Si-atom also contribute to the surface attachment formation. Some examples of halogen-substituted silanes used in pilot-testing the described here invention are: chlorotrimethylsilane, dichlorodimethylsilane, methyltrichlorosilane, dichloro-methylphenylsilane, phenyldichlorosilane, dichlorodiphenylsilane, octadecyltrichlorosilane, 1,7-dichlorooctamethyl-tetrasiloxane, 3,5-dichloroocta-methyltetrasiloxane, trimethylsilyl azide (azidotrimethylsilane), triethylsilyl trifluoromethanesulfonate, triethylsilyl acetylene and (3-mercaptopropyl)-trimethoxysilane (3-trimethoxysilyl-1-propanethiol).
By creating combinatory mixes of halogen-substituted silanes and other silanes, siloxanes, hydrocarbons and else exhibiting hydrophobic (water-repellent) properties, highly efficient water-repellent micro-thin surfaces are produced instantly when the mixtures are deposited as surfacing layer(s) via variety of derivatization approaches (spraying, mixing, evaporation, vacuumization, etc.). Varying the molecular ratios of the 1-, 2-, 3- or 4-halogen- and/or other-type of substituted (at a single silicone atom) silanes allows for adjusting the thickness and the density of the created nano-layers—i.e. (in the mixture) the higher the molecular ratios of the halogen-substituted silanes are, the higher is the thickness and the density of the resulting nano-layer formation. Also, the longer the hydrocarbon- (or other hydrophobic-) molecular chains of the substitutions at each silicone (Si) atom is—the higher is the thickness and the density of the resulting nano-layer; respectively—the greater is the hydrophobicity (water-repellency).
For the purpose of this invention, the length of each hydrophobic-chain substitution (at a silicone atom) is limited to a maximum 300 atoms [represented by “A” on the
The most important (claim 6) in this invention is the idea of applying the approach of mixing different compositions of silanes and siloxanes (in molecular ratios of mixed chemicals ranging from 0.001% to 99.999% between each-other—prior to their application onto the treated surfaces in order to compose the appropriate water-repellent properties (depending upon highly- or less-specific surface applications), rather than chemically designing and synthesizing single silane molecular structures alone—in order to employ similar to the above-mentioned repellant, attachment-active, encapsulation, optical and else properties. This approach allows for great flexibility in designing variations of different applications for variety of surface types. According to the invention, the composed polymer-preparation mixtures contain one, two or more of the components as follows: Components Type-1—silane substituted with 1, 2, 3, or 4 of the following—highly-reactive halogen atoms (such as F [fluorine], Cl [chlorine], I [iodine] and Br [bromine]) and/or the following chemically volatile (highly-reactive) chemical groups: azido-, acetylene-, mercapto-, sulfonate-, thiol-, methoxy-, methacryloxy-—at one-, more- or all silicone (Si) atoms of the halogenated silane molecule or at any other position of a particular molecule—in accordance to the common chemistry principles. For clarification, from one up to four halogen-substitutions are allowed at at-least one silicone or carbon atom, however as maximum as all silane atoms in a particular halogen-silane molecule may be substituted with halogen atoms as a matter of particular choice according to the general chemistry principles. More than one type of silanes chemically substituted with highly-reactive molecules may be used in each particular mixture depending upon particular applications. Preferable, but not the only matter of choice are silanes with 2- and/or 3 halogen substitutions per single molecular structure and at least one hydrophobic-group substitution such as alkyl-, aryl-, or else. The chemical formula for the substituted silanes used as a Components Type-1 is schematically represented by Xn—[Si]—Rm, where “R” is preferably an alkyl group having from 1 to 300 carbon atoms per R-radical, such as methyl-, ethyl-, n-propyl-, isopropyl-, n-butyl-, sec-butyl-, decyl-, dodecyl-, tetradecyl-, hexadecyl-, octadecyl-, etc. radicals. Examples of aryl groups represented by R are phenyl- and toloyl radicals. Examples of alicyclic groups represented by “R”, which are free of heteroatoms as constituents of the ring are —(CH2)5— and —(CH2)4— radicals, and an example of alicyclic groups represented by “R” which have a heteroatom as a constituent of the ring is a —(CH2)2—O—(CH2)2— radical. The methyl-radical is a preferred example of an alkyl group represented by “R” and the chlorine is a preferred example of the halogen elements represented by “X” where “X”-substitution represents any of the following reactive chemical groups—halogen-, azido-, acetylene-, mercapto-, sulfonate-, thiol-, methoxy-, methacryloxy-; “n” and “m” corresponds to the total number of substitutions containing “n” reactive groups (atoms) and “m” hydrocarbons (alkyl-, aryl-, alicyclic- or else groups). “[Sil]” in the formula stands for “silane” in which one or more silicone (Si) atoms are present within the silane molecule and each of them may be substituted; for the purpose of this invention silanes with any chemical structure can be used containing from 1 to 300 silicone atoms within a single silane and/or carbon-silane (organosilane) molecule. Components Type-2—cyclic silane, siloxane, hydrocarbon and/or their derivatives. The role of the cyclic molecules is to allow for creating higher nano-layer densities and a preferable layer growth in one dimension (i.e. enhanced 2-dimensional growth—in parallel of the surface applied on) rather than equal growth in all 3 dimensions. Another, Components Type-3, (applicable but not obligatory) also may be employed as been any other chemical substance exhibiting certain hydrophobic molecular properties and/or high affinity to react and substitute a halogen element from the silane molecule; some (but not only) examples of the latest are —H, —OH, C═C, C≡C, Metal-containing molecules and others. As an additional Components Type-3 type are used so-called composite carriers. Preferred nano(micro)-layer composite carriers which are relatively insoluble in the reaction medium are, for example, substances having hydroxyl groups on their surface capable of reacting in a strong manner with the halogenated silanes creating nanolayer composites. Examples of such substances are biological molecules and substances, acidic clays, such as for example Tonsil, montmorillonite and other aluminosilicates in the H+-form, zeolites, non- or porous glass (such as, for example, controlled pore glass), non- or porous ceramics (such as controlled pore ceramics), non- or porous silicon dioxide (such as precipitated or pyrogenic silica), non- or porous alumina and non- or porous mullite. Additional examples of preferred carriers which are insoluble in the reaction medium are dried hydrolysis products of functional silanes or polystyrenes, such as, for example, polystyrene which is cross-linked with divinylbenzene. Components Type-3 could itself be a multi-component mixture.
The invention's main core is the process for forming a silicon film on the surface of a substrate comprising the approach of preliminary preparation of single- or multi-component mixes containing at least one silicone component substituted with highly-reactive chemical group (as above-mentioned), which serves a highly important feature within the repellent layer when first surface-deposited and contacted with the air-born water humidity and/or water condensation: The spontaneous reaction of the monomer (organo)halogen-silanes with water molecules or hydroxyl groups (hydrolysis) [i.e. solvent-alcohol(s) or else—when used] produces silanols, which, using HCl catalysis, lead directly to further reacted oligomers or polymer siloxanes completing the repellant layer formation via directed- (designed-) (
The invented approach of initial pre-treatment preparation of multi-component mixes containing at least one halogenated silicone component serves as a highly important feature (as described) within the repellent layer when first surface-deposited and contacted with the water humidity from natural sources (humidity, rain, etc.): in particular cases, the spontaneous reaction of the monomer (organo)halogen-silanes with water (hydrolysis) [or applicable solvent-alcohol(s)] produces silanols, which, enhanced by HCl catalysis, lead directly to further reacted oligomers or polymer siloxanes completing the repellant layer formation (in the picture “Si” represents silicon, “O” stands for oxygen). The description “silicones” for the whole class of polysiloxanes is an imitation of the oxygen-carbon bonds of carbon chemistry which are known as “ketones”. (The latter however, because of their particular characteristics, form double bonds instead of single bonds); (
Mono-, di-, tri- or tetrafunctional siloxane units with Si—O bonds arise from polycondensation according to the number of chlorine atoms of the basic silane molecule. In the chemical industry, the diverse halogenated silanes serve as building blocks for the synthesis of the various types of silicones such as fluids, resins and nano-layers.
In our test-experiments, the halogen-substituted alkyl-silanes enable the formation of longer Si—O chains while carrying out hydrophobic properties. At first the hydrolysis of, for example, dimethyldichlorosilane gives a mixture of short chained, di-functional and therefore linear siloxanes with OH and groups as well as cyclic siloxanes having normally between three and fifteen chain units. The linear siloxanes show a helix structure with the methyl groups being freely able to rotate. All silicone fluids, emulsions and rubbers are based on dimethyldichlorosilane. This is therefore the decisive base product for the industry. Within our test combinations the halogenated-silane polycondensation interacts with the cyclosilane component in the mixture enhancing the nano-layer formation via direct substitution reactions and/or cyclic concatenation.
If the trichloro- (respectively, tri- or four-halogen-substituted) silane compounds are used, a cross-linking between the linear chains is produced as a result of the three- or four reactive sites of silicon atom. A three dimensional polymer network is the consequence. This process is crucial in the formation of silicone resins and thicker dense nano-layers.
Mono-chlorosilanes, on the other hand, because of their single reactive site, can be used predominantly for the terminating of the chain growth by polycondensation and for very limited single-molecule thickness of the resulting nano-layer. They react as a sort of “capping agent” for the growing silicone chain. Increasing their relative ration within a composed mixture leads to thinner and low-branched layer formation.
In addition to the simple hydrolysis reaction of halogenated silanes, variations of random halogen-replacement reactions occur in the silane mixtures described in this invention (as common in the Silane Chemistry)—all serving in repellant polymeric layer formation in situ. The particular variation in concentrations (molar ratios) of mono- and multi-halogen silane substitutes, cyclosilanes, hydrocarbons and carbon-silanes allows for best optimization of nano-layer formation as desired by a specific application's design—by taking into account the molecular reactions variations as a result of the molar ratios variations of the mixture components.
Test Conditions Specified amounts of silanes' solution mixtures (from the bottled solutions as numbered above) were center-spotted in the amounts specified below on a white cellulose paper napkin and on white cotton napkin at the positions specified below (image). A 20-μl Gilson automatic pipetter was used for the deposition of the mixtures. Spotted materials were dried for 20 min at 40° C. and then were completely soaked (immersed) for 30 minutes in a methylene blue/xylene cyanol dye solution in water. Then the dye-solution excess was removed by gently pressing the wet material between a paper-towel for 3 sec. and then air-drying for 30 min at 40° C. Black carbon-pencil mark (“+”) shows the center of the spotting (
The experimental result (
Comparing positions 2 and 3 shows the significant influence of the hydrophobic hydrocarbon chain on the water-repellant properties—i.e. the longer the chain is (position 3) the better the water-repellant protection is. This is better visible and distinguished when the air-gaps between the material support are larger (cotton napkin; right-image) compared to the smaller gaps (cellulose napkin; left-image).
Encapsulation of HL-60 human lymphocyte cells followed by fluorescent hybridization (
In vivo encapsulation attachment of D. virilis (fruit-fly) total organs by a solution of 1% of gamma-propylthriethoxy silane and 0.1% thrimethyliodosilane in ethanol (
Attachment of DNA oligonucleotides on glass slide surface.
Slides derivatization: Glass slides were cleaned by incubation in concentrated sulfuric acid for 20 min in ultrasound bath, washed in distilled water, treated with methanol-acetic acid (1:1) for 20 min, washed in 3 changes of deionized water—all in ultrasonic bath—and finally dried. Slides were derivatized with silane by ultasonication for 30 min in 3% silane solution in methanol or acetone or by direct immersion in concentrated silane solution for 5 seconds. Slides and silane solutions were processed in dehumidified chamber where derivatized slides were dried in dark. Slides were stored in dehumidified polyethylene bags in dark until use. Several 3 mm spots were performed (0.25 microlitters of 50 μM Cy3-labelled N14 oligonucleotide were deposed manually) with the same Cy-5 labeled 14-mer oligonucleotide onto glass slides derivatized with 3 different 3% silane solutions: solution 1—Trimethyliodosilane; solution 2—Azidotrimethylsilane; Solution 3—Triethylsilyl acetylene. The attachment of the oligo is instant upon contact. Slides were heated at 60° C. for 30 seconds for complete drying. Slides were scanned before and after wash to remove the unbound oligonucleotide and provide for binding efficiency.
Cy-5 labeled oligonucleotide attachment to the silanated glass-slide surface are provided on
In conclusion, after testing 22 different silane we observed that the silanes with highly reactive chemical groups with affinity to hydroxyl groups demonstrated best efficiency. Also in considering the best performers, important feature is the hydrophobicity of the silane layer. Extreme hydrophobicity leads to very-small dots and less-efficient deposition even if the reactivity of the attachment is high leading to a preference of silanes demonstration a low hydrophobicity. Trimethyliodosilane is one of the most reactive silylating agents. Hydroxyl groups are silylated immediately, keto groups yield the pure silyl enol ether within a few min. Slight drawback with this application of MIS is the formation of dehydrated products. This can be avoided by using only very small amounts of catalyst, by protecting from light and by addition of a of primary ammines, especially N,N-bis-(tri-methylsilyl)-cyclohexylamine. The Trimethylsilyl azide (=Azidotrimethylsilane), is known to silylate primary and secondary alcohols and phenols very rapidly and efficiently at room temp. Tertiary alcohols do not react under the reaction conditions employed. The only by-product of this mild silylation method is the gaseous NH3. Triethylsilyl acetylene was found to be demonstration the third most efficient performance in attaching oligonucleotides.
Oligonucleotide attachment and cDNA hybridization on nylon membrane attached onto glass-slide surface by a mixture of Trimethyliodosilane (10%) and Decamethylcyclopenta-siloxane (90%).
Description of the Method: GeneScreen nylon membrane was attached onto a glass slides by immediate top-deposition on the slide after the slide immersion in a mixture of Trimethyliodosilane (10%) and Decamethylcyclopentasiloxane (90%) and gravitationally adsorbing the solution excess. The membrane is steadily attached right after liquid drying (optionally accelerated by heating for 15-20 min at 60° C. 13-, 15- and 17-mer oligonucleotides were robotically deposited onto the membrane by 0.3 mm pin-array and Beckman Biomek 2000 spotting robot (3 repeated spotting per dot). Cy3-labeled cDNA target from mouse kidney was hybridized onto two arrays and the array were scanned immediately after concluding the hybridization and after wash for 40 minutes at 65° C. in 7% Lauroyl sarcosine, 1% SDS with shaking.
Experimental Result and Conclusion: The membrane retention to the glass was superior even after the extremely harsh washing conditions. The result is presented on
Direct oligonucleotide attachment onto silane-modified glass by micro-printing (0.05-0.1 mm spots) with Lucidea spotting robot.
Description of the Method: Cy3-labeled oligonucleotide and Cy3-deoxynucleotide attachment onto glass slide by micro-drop deposition by using Lucidea spotting robot. On the top rows of each slide we deposed 3× to 30× diluted 50 μM Cy3-labelled N14 oligonucleotide in water-solution of 40 μM herring sperm DNA shredded to a 17-mer size. On the bottom rows of each slide was deposed 1 μM water-solution of Cy3-dUTP. Lucidea spotting robot (Amersham-Pharmacia Biosciences) was used for spotting on 10 slides with unpolished surfaces derivatized with 100% Trimethyliodosilane and another 10 slides were derivatized with Azidotrimethylsilane. Slides were heated for 30 seconds at 60° C., scanned, washed by 10-times immersion in water, dried and scanned again to calculate the remaining attached (oligo)nucleotide.
Experimental Result and Conclusion: (1) Iodotrimethylsilane offers quick and efficient derivatization of solid substrates for nucleic acid attachment without any other treatment. The oligonucleotide attachment is superior to any other known method or glass-derivatized surface except direct chemical synthesis by laser photo-patterning. (2) Heating at 50-70° C. improves the attachment. (3) Because of the glass-slide surface discrepancies, both nucleic-acid's deposition and attachment are highly variable across the slide and among the slides. For elimination of this problem, silicon wafers or metal-monolayer-derivatized slides are recommended for microarray preparation instead of regular microscopic glass-slides or slides must be finely polished. (4) The significantly higher signal saturation of the single-nucleotide labeled dots compared to the lower-intensity of the oligonucleotide dots is due to the fact that each dUTP molecule is attached to the Cy3 fluorochrome, while only one nucleotide of the 14-nase oligo is attached to a Cy3 molecule. Results are presented on
Protein attachment and biotin-streptavidin attachment reaction on glass slides derivatized with azidotrimethylsilane.
The method is used to test for both the protein (antibodies) attachment to the azide-group-derivatized glass surface and its retention, and the efficiency of SAPE (phycoerythrin-labeled streptavidin) binding to the biotinylated anti-streptavidin antibodies. The biotinylated anti-streptavidin antibodies were attached onto glass slides by micro-deposition of 0.25 microliters of each of the following antibodies solutions: 1 mg/ml in PBS, 10× diluted solution, and 100× diluted solution as shown from the top to bottom on the slide images (to the Left) of
Experimental Result and Conclusion: Although the
We found that the surface hydrophobicity had much less impact on the protein deposition than on oligonucleotide one, probably due to the fact that the proteins had much higher molecular weight. Depositing larger nucleic acid molecules instead of short oligonucleotides may reveal the similar outcome. Combinations of more than one derivatization silanes will probably be more beneficent due to coupling properties.
Testing surface repellency on different commercially important materials treated with surfacing mixtures.
At last, variety of commercially valuable materials were tested for their penetration and impregnation-ability while treated with different silane mixtures. A small representation pick of all performed tests is shown on
The above described test-experiments well support the main claims of the invention giving the preference of combining variety of pre-manufactured compounds possessing specific properties and combining them with ones having highly-reactive chemical residues capable of polymerizing and forming thin layers with pre-designed thickness and properties matching specific practical needs. Since the demand for impregnation- and surfacing layers is growing over the years, this invention may be considered of high importance in wide industrial, scientific and medical area of application.
This application is claiming the priority benefit of the provisional patent application U.S. 61/786,119 “Method and substrate for covalent attachment and encapsulation of biological, chemical and physical substances”.
Number | Date | Country | |
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61786261 | Mar 2013 | US |