Polymethylsiloxane polyhydrates having supramolecular properties of molecular capsules, method for producing same, and adsorbents containing same

Abstract

The present invention relates to polymethylsiloxane polyhydrates having supramolecular properties of molecular capsules, a method for producing the same, and adsorbents containing the same. The present invention relates to a method for producing a polymethylsilanetriol, the method comprising: polycondensing a metasilanesolution with an acid, the metasilanesolution being obtained by mixing at a temperature higher than 90 DEG C at a ratio of 0.84 mol to 0.9 mol of a base per mol of polymethylsiloxane contained in methylsilanetriol, and adding an electrolyte in an amount of 0.025 mol to 0.1 mol per mol of the base; polymethylsiloxane polyhydrates with supramolecular properties produced according to the method are particularly useful in chemistry, medicine and veterinary medicine.

Description

Technical Field

[0001] The present invention relates to a method for producing an adsorbent having supramolecular properties of a molecular capsule, in particular a method for producing polymethylsiloxane polyhydrate (methylsilicic acid hydrogel) for use in chemistry, medicine and veterinary medicine. Background Art

[0002] Polymethylsiloxane polyhydrate (hereinafter referred to as PMSPH) is produced from a solution of methylsilanetriol (methylsilanetriol, CAS 2445-53-6, https: / / pubchem.ncbi.nlm.nih.gov / compound / 61844) in an alkali (potassium hydroxide or sodium hydroxide).

[0003] Methylsilanetriol is a hydrolysis product of methyltrichlorosilane (methyltrichlorosilane, CAS 75-79-6, https: / / pubchem.ncbi.nlm.nih.gov / compound / 6399). It is a granular substance with polymer properties and a water content of 40% to 60%. The molecular formula is:

[0004]

[0005] where n is the number of keys,

[0006] k is the branching index that determines the degree of crosslinking or branching,

[0007]

[0008] where mod is a mathematical function that returns the remainder of a number divided by another number.

[0009] p is external (i.e., not chemically bound) water,

[0010] .

[0011] As can be seen from the overall molecular formula of methylsilanetriol, it belongs to the class of polymethylsiloxanes and hereinafter the more precise terms "polymethylsiloxane" (PMS) or "polymethylsiloxane contained in methylsilanetriol" will be used instead of the term "methylsilanetriol (dehydrate)".

[0012] The properties of polymethylsiloxanes and methods of producing polymethylsiloxanes are described in various publications, such as RG Jones, W. Ando, ​​J. Chojnowski, "Silicon-Containing Polymers: The Science and Technology of Their Synthesis and Applications", Springer Science & Business Media, 2013, 768 pages, which contains detailed information on the synthesis and properties of organosilicon compounds (including polymethylsiloxanes). A broad overview of the principles and mechanisms, synthesis methods, characteristics and properties of materials formed using the sol-gel method is given in S. Sakka's Handbook of Sol-Gel Science and Technology (Kluwer Academic Publishers, 2005, 1986 pages).

[0013] MG Voronkov, VP Mileshkevich and Yu.A. Yuzhelevsky, Siloxane Linkage, Novosibirsk, Nauka, 1976, p. 413, discloses information on the nature of siloxane linkages and their influence on the physical properties of compounds, as well as a review of silanols and siloxanol polycondensation processes.

[0014] In addition, many patents describe the discovery of some special properties of polymethylsiloxane in the form of polyhydrates. Patent RU 2761627 C1 (December 1, 2020) describes a method for producing PMSPH from sodium methyl silicate and hydrochloric acid. Characteristics of the reagents used: For sodium methyl silicate solutions, the density is 1.2 to 1.3 g / cm 3 ; For hydrochloric acid solutions, the concentration is 12.0% to 14.0%. The authors crush the gel formed and then wash it to neutral acidity. The resulting product has a particularly high adsorption quality.

[0015] Patent RU 2111979 C1 (March 11, 1994) discloses a method for producing methylsilicic acid hydrogels from sodium or potassium methylsilicic acid and a strong acid (hydrochloric acid or sulfuric acid according to the claims of the invention). The authors give the characteristics of the quantitative content (1.75 to 2.30 mol / L) of sodium and potassium methylsilicic acid solutions.

[0016] Invention certificate SU 137113 (August 19, 1960) describes the production of highly dispersed hydrophobic methylsilicic acid hydrogel powder by mixing sodium methylsilicic acid with acetic acid. The authors call the product "silicon dioxide", but the chemical formula of the final compound is similar to PMSPH. The concentration of the sodium methylsilicic acid solution is 12.5%.

[0017] The mentioned technical solutions also allow for the inclusion of various useful chemical and / or biological additives, however, the reviewed technical solutions are mainly aimed at producing products with high adsorption properties and the additives have no significant effect on improving the adsorption properties of the obtained products.

[0018] New possibilities for exploiting the properties of methylsilicic acid hydrogels are disclosed in patent UA 115857 C2 (August 30, 2017), which describes a method for producing methylsilicic acid hydrogels with supramolecular properties. The polycondensation of a methylsilicate solution is carried out using a gaseous acid. The resulting supramolecular properties are achieved for the first time, but the production method is difficult to implement, requires special equipment, and works under high pressure.

[0019] The closest prototype of the technical solution under consideration to actually produce PMSPH is mentioned in patent RU 2293744 C1 (December 22, 2005). This patent provides the theoretical basis for the chemical formula of the final product of polymethylsiloxane polyhydrate, but it does not solve the problems related to the composition of the alkaline stock solution of sodium dihydroxymethyl silicate, indicating that only one substance is present in the composition of this solution and only a narrow water content range is provided for the gel form of this substance. In addition, this patent does not consider the possibility of giving the product supramolecular properties.

[0020] It should be noted that all the above technical solutions do not pay proper attention to the composition quality of sodium methyl silicate or the original metasil solution, resulting in the formation of low molecular weight fractions during the polycondensation process, thereby affecting the product properties by reducing the purity of the obtained product (i.e., lower quality), hindering the substitution reaction, and reducing the yield of the obtained product. Summary of the invention

[0021] The invention solves the technical problem of producing polymethylsiloxane polyhydrate with supramolecular properties of molecular capsule quality and improving the yield and purity of the obtained product.

[0022] In order to solve the above problems, a method for producing a polymethylsiloxane polyhydrate having supramolecular properties of a molecular capsule is proposed, wherein an acid is applied to a metasil solution to cause polycondensation, and the solution is mixed at a temperature above 90° C. with a ratio of 0.84 to 0.9 mol of a base per 1 mol of polymethylsiloxane contained in methylsilanetriol, and an electrolyte is added in an amount of 0.025 to 0.1 mol per mol of the base. The base is sodium hydroxide or potassium hydroxide.

[0023] The electrolyte may be a chloride, bromide, iodide, nitrate, nitrite, carbonate, sulfate, sulfite, acetate, oxalate, succinate, formate, citrate or a mixture of these salts of lithium, sodium, potassium, ammonium.

[0024] The electrolyte contributes to the supramolecular properties of the material, as well as the variation in the n range.

[0025] The addition of electrolytes to methylsilanetriol alkaline solutions leads to the formation of unique polymethylsiloxane polyhydrates (PMSPH) with supramolecular properties of molecular capsules, which represent a new direction in the field of material properties.

[0026] Polymethylsiloxane polyhydrate with supramolecular properties has the following structural chemical formula:

[0027] .

[0028] The obtained PMSPH has a high adsorption capacity, which makes it a useful adsorbent. The structure of PMSPH can be described as a dimer of variable composition with a polyhydrate shell.

[0029] The chemical formula of polymethylsiloxane polyhydrate and its properties vary depending on the range of n. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 - The region where m-mers (1≤m≤3) are formed when methylsilanetriol is dissolved in an alkali.

[0031] in:

[0032] When (8≤n≤∞), the bottom set of lines represents 3-mers,

[0033] The middle set of lines represents the dimer,

[0034] The top set of lines represents monomers. DETAILED DESCRIPTION

[0035] The authors of the present invention have detailed the chemical formula of polymethylsiloxane polyhydrate by confirming the composition of a metasil solution containing a group of dipolysiloxanol derivatives, expanding the water content range of the substance in the gel form, and determining the water content range of the substance in the paste form and suspension form. By adding an electrolyte solution to the metasil solution, the authors of the present invention have produced the resulting compound with unique supramolecular properties of molecular capsules.

[0036] To evaluate the completeness of polymer branching and the crosslinking or branching degree index (k), a normalized binding index (I(b)—binding index) was used, with values ​​ranging from 0 (0%) to 1 (100%), corresponding to I(b) = 0 for a linear polymer structure and I(b) = 1 for a fully condensed structure.

[0037] The relationship between the I(b), k and k(max) indices is defined by the following ratio:

[0038] .

[0039] In the production of a solution of polymethylsiloxane in a base (the conventional symbol for the base is MeOH), the interactions are described by the following stages:

[0040] Stage 1 - debranching of the molecule by breaking the intramolecular siloxane bonds under the influence of a base;

[0041] Stage 2 - Breaking of the siloxane bonds of the macromolecule to form small molecules;

[0042] Stage 3 - Substitution of hydroxyl groups with alkali metal cations to form OMe groups.

[0043] Now let's look at each stage in detail.

[0044] It should be noted that in the reaction equations below, water is not indicated in the chemical formulas of the compounds because water does not interact chemically in these reactions.

[0045] Phase 1

[0046] The chemical reaction equation for this stage is:

[0047]

[0048] The amount of alkali consumed in this stage is proportional to the degree of branching of the original polymethylsiloxane molecule.

[0049] Phase 2

[0050] The chemical reaction equation for the formation of the intermediate and subsequent separation of the m-sized fragment from the n-sized main molecule has the following form:

[0051] .

[0052] Smaller molecules with size m (m-mers) are formed from molecules of size n according to the following reaction:

[0053] .

[0054] Where A = m * (x - y)

[0055] B = (n - m) * (x - y)

[0056] D = m * (n - k + 1) + n * (1 - y)

[0057] E = m * (k - n - 1) + n * (x - 1).

[0058] Phase 3

[0059] In the presence of an equal amount or excess of base, substitution reactions of small-sized linear fragments may occur.

[0060] The chemical reaction equation is:

[0061] .

[0062] All three stages are feasible and may occur during the interaction of the polymethylsiloxane contained in the methylsilanetriol with the base.

[0063] The purpose of the present invention is to theoretically evaluate the process of producing the product of the interaction of methylsilanetriol with a base, to verify the theoretical evaluation in practice, to optimize and control the production process of the methylsilanetriol alkaline solution, and to improve the subsequent stages of the production of polymethylsiloxane polyhydrate (PMSPH).

[0064] By combining stage 1 and stage 2 (chemical reaction equations (1) and (2.1)), the production model of smaller fragments can be studied, as well as quantitatively and qualitatively evaluated. For this purpose, the reaction equation is derived and the stoichiometric coefficients of the equation are calculated. In order to make the calculation feasible, a method of forming a half-reaction equation by forming two fragments of the same size (m-mers) is selected. Taking into account the conditions for the formation of the reaction products, the full reaction equation is derived by combining the half-reaction equations. The initial premise is that during the interaction of polymethylsiloxane with the base, fragments of size m are formed, and the possibility of forming reaction products of sizes ranging from monomers (m=1) to trimers (m=3) is considered.

[0065] The chemical equations for the reactions in stage 1 and stage 2 are:

[0066]

[0067] When it is possible to form products (D ≥ 0; E ≥ 0), the range of k values ​​is:

[0068]

[0069] in

[0070] .

[0071] It has been determined that in order to obtain smaller fragments of size m, the amount of base consumed depends on the size of these fragments (the value of m) and that the ratio of base required per 1 mol of polymethylsiloxane is mol.

[0072] In order to determine the ratio of alkali to PMS in the production of the previously patented product polymethylsiloxane polyhydrate (patent RU 2293744 C1 (December 22, 2005)), the production material balance of each stage of metasil production was studied. It was found that the actual ratio of alkali to PMS in the methylsilicone solution production stage was a value of 0.85 ± 0.05 mol of alkali per 1 mol of PMS. Since the authors used a component ratio of less than 1, it is incorrect to state that a solution of polymethylsiloxane in a base is a known product of sodium methyl silicate (sodium methyl silicate, CAS 4493-34-9 https: / / pubchem.ncbi.nlm.nih.gov / compound / 23704354) or a known product of potassium methyl silicate (potassium methyl silicate, CAS 18089-65-1 https: / / pubchem.ncbi.nlm.nih.gov / compound / 23689131 or CAS 65351-55-5 https: / / pubchem.ncbi.nlm.nih.gov / compound / 6455118).

[0073] Therefore, the substance produced by the authors during the dissolution of polymethylsilicate contained in methylsilanetriol in alkali is novel. The authors propose to call this substance "metasil solution".

[0074] By modeling the composition of the reaction products using the reaction scheme (4), and further producing and studying samples of the substances described by these models, results unknown in the prior art were obtained.

[0075] There is no direct way to determine the structure of methylsilanetriol, since the substance contains hydroxyl groups which, at the slightest influence (change in acidity, temperature or other chemical and / or physical factors), lead to a rearrangement of the uncondensed hydroxyl groups and thus to changes in structure and composition. In addition, the substance contains physically bound water, which represents a separate phase.

[0076] Since methylsilanetriol is a hydrolysis product of methyltrichlorosilane, the substance is a spatially crosslinked polymer with a variable composition and contains a group of molecules with different lengths (different n values) and different k branching index values ​​(MG Voronkov, Yu.N. Murinov, et al., Influence of conditions of hydrolytic polycondensation of methyltrichlorosilane on the sorption properties of the resulting silicon polymers, High-molecular compounds, Series A, 2000, Vol. 42, No. 7, pp. 1175-1182). Based on the data provided by the authors of this article, the binding index of the product structures obtained using various process schemes was calculated. The values ​​of the I(b) binding index of the obtained substances ranged from 0.4 to 1, with an average value of 0.76. The average value of the I(b) binding index ranged from 0.62 to 0.88.

[0077] It should also be taken into account that methylsilanetriol does not consist of linear molecules, since the byproduct hydrogen chloride formed during the hydrolysis of methyltrichlorosilane does not allow the formation of a linear molecule with the chemical formula [(CH3Si) n O (n-1) OH (n+2) ] ∙ The molecule in completely linear form at pH2O (VM Kopylov, LM Khananashvili, OV Shkolnik, AG Ivanov, Hydrolytic polycondensation of organochlorosilanes (review), High-molecular compounds, Series A, 1995, Vol. 37, No. 3, pp. 394-416). In this context, the value of the k branching index or the I(b) binding index is always greater than zero. For structures with a branching index k=k(max) or I(b)=1, they are characterized by hydrophobicity, since such structures do not contain hydrophilic groups. When methylsilanetriol is added to water and the solution is then evacuated to remove air, methylsilanetriol completely precipitates to the bottom of the container. This fact indicates that there are no structures with a branching index k=k(max) or I(b)=1 in the composition of methylsilanetriol. Therefore, methylsilanetriol is a spatially crosslinked molecule with the following general formula:

[0078]

[0079] where n is the number of bonds;

[0080] k is the branching index, where 2 ≤ k ≤ (0.5n - 0.5(n mod 2)),

[0081] p is the external (i.e., not chemically bound) water,

[0082] .

[0083] To determine the composition of the m-mer in the PMS alkali solution, the authors calculated the reaction products according to reaction equation (4). Based on the dependence of the component ratio base:PMS on the I(b) binding index in the original polymethylsiloxane, the boundaries of the m-mer formation region were calculated. When performing the calculations, the following aspects were considered:

[0084] - The polymethylsiloxane of methylsilanetriol does not contain completely linear (k = 0) or cyclic (k = 1) or completely bonded (k < k(max) - 1) structures in terms of composition (formation conditions 2 ≤ k ≤ (0.5n - 0.5(n mod 2)));

[0085] - Considering the above conditions, the minimum number of units (n) in the polymethylsiloxane of methylsilanetriol is 8;

[0086] - The maximum number of units (n) in methylsilanetriol tends to infinity ;

[0087] - To eliminate the dimensionless nature of the component ratio function, the I(b) normalized binding index was used as a parameter of this function.

[0088] The dependence function of the component ratio (mol / mol) on the binding index has the following form:

[0089] ,

[0090] where [MeOH / PMS] is the molar ratio of the components when PMS is dissolved in the base,

[0091] n is the number of units of the polymethylsiloxane contained in methylsilanetriol,

[0092] k(max) is the maximum possible branching index within the PMS molecule with n units ,

[0093] I(b) is the binding index ,

[0094] m is the size of the m-mer obtained through reaction (1) (1 ≤ m ≤ 3).

[0095] The m-mer formation region and the comparison with the component ratio used in the actual production of PMSPH are shown in Figure 2. Figure 1 as shown in .

[0096] exist Figure 1 In the figure, several groups of lines represent the region of m-mer formation during the dissolution of polymethylsiloxane of methylsilanetriol in base (when 8≤n≤∞, the top group of lines represents monomers, the middle group of lines represents dimers, and the bottom group of lines represents trimers). The resulting groups of lines with slope ratios of (0.5+1 / n) (for different values ​​of n in PMS) limit the minimum value of the component ratio to obtain a specified m-mer. Therefore, in order to form monomers from PMS (m=1, top group) when the binding index is 0.1≤I(b)≤0.41, the ratio of base component:PMS must be greater than 1.20:1; in order to form monomers from PMS when the binding index is 0.42≤I(b)≤0.77, the ratio of base component:PMS should be greater than 1.39:1. From Figure 1 It can be clearly seen in the graph shown that when the ratio of the base component: PMS is at a level of 0.8:1 (the ratio of components used to produce PMSPH calculated according to patent RU 2293744 C1), the reaction product is a dimer obtained from PMS when the binding index is 0≤I(b)≤(0.60-0.66), and a trimer when the binding index is (0.60-0.73)≤I(b)≤0.94. When the ratio of the base component: PMS is at a level of (0.83-0.9):1, the reaction product is only a dimer obtained from PMS when the binding index is 0-0.83. The data obtained are consistent with the data given in the literature by MG Voronkov, Yu.N. Murinov et al., Influence of conditions of hydrolytic polycondensation of methyltrichlorosilane on the sorption properties of theresulting silicon polymers, High-molecular compounds, Series A, 2000, Vol. 42, No. 7, pp. 1175-1182, and also confirm the conclusion mentioned above, that is, the solution of polymethylsiloxane in alkali is not a solution of CH3Si(OH) x (ONa) (3-x) or CH3Si(OH) x (OK) (3-x)A known product of sodium methyl silicate or potassium methyl silicate, wherein 0≤x≤2.

[0097] For each PMS structure in methylsilanetriol, when a PMS consisting of structures with a branching index value of 0≤k≤k(max) is used, the amount of base required per mol of PMS is in the range of 0.9 mol (when k=0) to 1.5 mol (when k=k(max)) to allow the formation of monomers (m=1). When a base to PMS molar ratio in the range of 0.45 (when k=0) to 1.0 (when k=k(max)) is used, the reaction product is a dimer (m=2). In order to form trimers (m=3), the ratio should be 0.28 to 0.83. Since the ratio ranges for the formation of dimers and trimers overlap, in order to obtain a set of strict dimers, a base to PMS molar ratio in the range of 0.84-1.0 should be used. Considering that in practice the PMS contained in methylsilanetriol does not consist of structures in the entire k-branching index range, and considering that the maximum practical molar ratio of base to PMS is 0.9, the recommended range of base:PMS molar ratio in order to obtain dimers would be 0.84-0.9. Therefore, the authors conclude that, based on the data provided, varying the base:PMS molar ratio allows for the directed synthesis of m-mers while obtaining the predicted reaction products.

[0098] In view of the above, it is obvious that in the actual production of the methylsilanetriol alkaline solution, the product described in stage 3 (substitution reaction according to equation (3) in which OMe groups are formed) is not formed.

[0099] Unexpectedly, the resulting solution of methylsilanetriol in base contained all possible dimer structures. For the dimer, the composition was expected to be composed mainly of molecules containing two OMe groups. The actual composition of the solution of methylsilanetriol in base is shown in Table 1.

[0100] Table 1

[0101] At different [MeOH] / [PMS] molar ratios

[0102] Composition of the solution of methylsilanetriol in alkali

[0103]

[0104] Since the composition of the mixtures obtained in practice is not homogeneous, an additional problem arises, namely the need to obtain a homogeneous mixture for the purpose of further studies, standardization and being able to compare with real mixtures. To solve this problem, theoretical calculations were used. Thus, for substances with a value of k = (n / 2 + 1) (I (b) = 1), it was possible to obtain a homogeneous mixture at a methylsilanetriol: base ratio of 1: 1 or a homogeneous monomer mixture at a methylsilanetriol: base ratio of 1: 1.5 during the implementation of stages 1 and 2. The composition of the dimer mixture is shown in Table 1 (MeOH / PMS ratio = 1.0). Obtaining substances with a value of k = (n / 2 + 1) (I (b) = 1) is not a problem, since the dehydrated methylsilanetriol has this structure. The dehydration of methylsilanetriol can be carried out by any available method: thermal or low-temperature drying at atmospheric pressure or vacuum, dehumidification, etc. The authors used vacuum drying (temperature 70 ° C to 80 ° C, pressure 0.03 to 0.05 MPa) to dehydrate methylsilanetriol.

[0105] During the gelation of PMSPH and acid solution from methylsilanetriol base solution, several parallel processes occurred in the system:

[0106] - Due to the structural growth caused by intermolecular cross-linking, MeA-type salt (Me is an alkali metal and cation A is an anion) is formed as a reaction product;

[0107] - Structural polycondensation due to intramolecular crosslinking, mainly due to OH groups;

[0108] - A reaction in which the OH group is replaced by the OMe or A group due to a reversible substitution reaction that occurs when interacting with the intermolecular cross-linking reaction product.

[0109] The polycondensation process is accompanied by intermolecular crosslinking, occurs at different rates and slows down as the viscosity of the system increases. Compared with the other processes described, the polycondensation reaction is accompanied by intermolecular crosslinking with the highest rate. The OMe group participates in this process.

[0110] The intramolecular structural polycondensation process occurs at a slow rate, is reversible, and depends on the acidity, viscosity, temperature, and size of the molecule. This process mainly involves OH groups, which are therefore less reactive than the OMe groups of the above process.

[0111] The substitution reaction is the slowest process and depends on the concentration and viscosity of the salt formed. As the first process (condensation polymerization with intermolecular crosslinking) occurs, Me (+) As reaction products, cations can react with H (+) The ions undergo a substitution reaction to form OMe groups.

[0112] At the gelation point, the reaction mixture separates into two parts: an insoluble gel and a soluble sol. The insolubility of the gel can be explained by the fact that it represents a single spatial network, in which the individual chains are chemically closely connected to each other. At the gelation point, the number average molecular weight is small, and the mass average molecular weight tends to infinity (SV Vdovina, E.Yu.Bondyreva, Polycondensation: Guidelines for self-study, Nizhnekamsk, Nizhnekamsk Institute of Chemical Technology, branch of the Federal State Budgetary Educational Institution of Higher Professional Education "KNITU", 2014, p. 28).

[0113] After reaching the gelation point, the amount of sol begins to decrease rapidly due to the transformation of sol into gel. The viscous reaction mass first turns into an elastic mass and then into a solid, infusible and insoluble product. Along with the intermolecular process, reactions may also occur between functional groups with the same network structure.

[0114] All the above arguments indicate that PMSPH produced from a solution of methylsilanetriol in a base at a MeOH / PMS molar ratio of 0.84 to 0.9 is a dimer with a variable composition, as a basic unit, with a polyhydrate shell, and a mass average molecular mass tending to infinity. Structurally, this polymethylsiloxane polyhydrate is represented by the following chemical formula:

[0115] ,

[0116] in

[0117] For products in gel form, q typically ranges from 60 to 92;

[0118] For products in paste form, q typically ranges from 89 to 134;

[0119] For products in suspension form, q typically ranges from 133 to 241.

[0120] The authors modeled the polycondensation process with intermolecular crosslinking. For this purpose, random half-reactions between the initial m-mers were generated, the probability of forming (m+m)-mers was evaluated, the equilibrium of the intermediate and final stages of the interaction was compiled, and the next stage of the process was calculated.

[0121] The results obtained show that a whole set of low-reactive OH groups (e.g., (CH3Si)4O3(OH)6, (CH3Si)8O7(OH) 10 etc.), and a reduced number of oligomers with mixed low-reactivity OH groups and reactive OMe groups (e.g. (CH3Si)4O3(OH) x (OMe) 6-x , where 1≤x≤5, (CH3Si)8O7(OH) x (OMe) 10-x , where 1≤x≤9, etc.), or a whole set of reactive OMe groups (e.g. (CH3Si)4O3(OMe)6, (CH3Si)8O7(OMe) 10 The presence of low molecular weight fragments in the IR spectrum confirms this data.

[0122] The low-reactivity m-mers present are capable of intramolecular condensation after reaching a certain size, as described above. The accumulation of low molecular weight (4-mer, 8-mer, etc.) fragments does not lead to the normal gelation process, but actually blocks the main product with fine fractions, resulting in a decrease in the actual yield of the target product (PMSPH) and preventing the substitution reaction of OH groups with OMe groups (the above-mentioned substitution process).

[0123] The authors were able to eliminate the problems, increase the yield of the target product and reduce the formation of low molecular weight fractions during the gelation of PMSPH. The claimed results were achieved by adding an additional amount of electrolyte in the range of 0.025 to 0.1 mole per mole of base to the mixture during the dimer formation stage during the dissolution of methylsilanetriol in a base. The electrolyte is a salt or a mixture of alkali metal or ammonium salts. The unexpected result is that the polymethylsiloxane polyhydrate gel precipitated by an acid solution exhibits supramolecular properties.

[0124] The supramolecular properties of matter refer to the properties and behavior of complex structures formed by molecules through intramolecular and intermolecular interactions. In addition to strong and directional chemical bonds, weak intermolecular interactions such as hydrogen bonds, hydrophobic interactions, ion-dipole interactions, and van der Waals interactions occur over longer distances and are not limited to certain directions.

[0125] Supramolecular properties include the following characteristics:

[0126] - Self-organization – the ability of molecules to form well-defined structures without external influence;

[0127] - Recognition and binding – molecules are able to interact and bind to other molecules through specific interactions such as host-guest interactions;

[0128] - Supramolecular chemistry - exploiting weak intermolecular interactions to control the synthesis and manipulation of complex structures;

[0129] - Material properties – Supramolecular systems can possess unique physical and chemical properties, such as viscosity, optical and electronic properties, and can self-heal and change their structure under the influence of external stimuli.

[0130] The ability to control the structure of supramolecular architecture under external influences (such as changes in environmental properties such as light and force fields) provides the possibility to control the structure and properties of the resulting supramolecular substances (crystals or polymers).

[0131] The property of a substance to confine molecules of another substance within its own cavity or several cavities due to condensation polymerization of the cavity terminal groups can be called "guest confinement by intramolecular or intermolecular condensation polymerization". This property is based on the ability of a substance to form polymer chains by condensation polymerization reactions between terminal groups within a molecule or between molecules.

[0132] This property may be the key to making supramolecular materials that can effectively bind and confine guest molecules inside their structures. This could be useful in drug storage and delivery, catalysis, sensing, and other applications where the controlled encapsulation and release of guest molecules plays an important role.

[0133] One class of known supramolecular substances is the molecular capsule (Donald J. Cram, Jane M. Cram, Container Molecules and Their Guests, University of California, Los Angeles, USA, 1994). Molecular containers (capsules) are formed by the self-assembly of molecules of a substance. They can be organic or inorganic in nature and have a cavity that can capture guest molecules. One of the main characteristics of molecular capsules is that they can close or "block". This is particularly due to the possibility of polycondensation or polymerization of the end groups of the substances that form the shell of the molecular capsule. Polycondensation allows the end groups of the shell molecules to bind, thereby causing them to close and form a stable structure.

[0134] The closed cavity of the molecular capsule provides protection and retention for the guest molecules inside. This can be used to:

[0135] - Controlled drug delivery;

[0136] - Encapsulation of harmful or toxic or target substances, followed by emptying of the "closed" molecular capsule and the possibility of further use of the substance after the molecular capsule is "opened";

[0137] - Catalyze chemical reactions;

[0138] - Provide unique reaction medium for fine chemical synthesis.

[0139] Molecular capsules are an active research area in nanotechnology and supramolecular chemistry. They may be used in a variety of applications, including medicine, chemistry, energy, and materials science.

[0140] The supramolecular properties of PMSPH produced according to the proposed method were evaluated on the basis of the assumption that PMSPH has the following properties:

[0141] - The guest substance (marker substance) cannot be qualitatively determined in a separate phase (e.g., a solvent for the guest substance) because the guest substance is encapsulated (locked) in the PMSPH molecular capsule due to the influence of the factors that trigger the molecular capsule locking on the PMSPH molecules;

[0142] - The guest substance (labeled substance) can be quantitatively determined in any manner in a separate phase (e.g., a solvent for the guest substance) because the guest substance is not encapsulated in the PMSPH molecular capsule due to the influence of the factor that triggers the unlocking of the molecular capsule on the PMSPH molecules.

[0143] Molecular capsule unlocking often only occurs after the guest substance is locked in the molecular capsule.

[0144] If PMSPG does not exhibit the continuous property of locking and unlocking the guest species, it means that the GMSPH does not have supramolecular properties and does not form a molecular capsule.

[0145] Description of Embodiments

[0146] Determination of supramolecular properties of polymethylsiloxane polyhydrate (PMSPH)

[0147] 1. A weighed portion of PMSPH with known specific adsorption capacity for the marker substance at a pH ranging from 1.0 to 10.0 is quantitatively transferred to the column and compacted using a plunger. The column is a glass or plastic tube with a diameter of more than 40 mm and a height of more than 200 mm, with a filter, narrowed to a diameter of 3 to 5 mm, and a two-way valve at one end.

[0148] 2. Add 0.0001 to 0.0005 M sodium hydroxide or potassium hydroxide solution to the column until the pH of the solution at the column outlet is in the range of 8.5 to 10.0. In this improved measurement embodiment, no alkaline solution is added.

[0149] 3. On top of the PMSPH layer, a certain volume of a marker substance solution calculated by measuring the specific adsorption capacity of PMSPH is poured into the column. Methyl orange or bovine serum albumin (BSA) is used as a marker substance; however, the list of marker substances is not limited to the above substances.

[0150] 4. The mixture is kept for 1.5 to 2 hours, which is necessary for the polymethylsiloxane to bind to the polyhydrate of the marker substance, and a calculated volume of 0.0001 to 0.0005 M acid solution (hydrochloric acid or sulfuric acid or citric acid) is added to the column until the pH at the column outlet is in the range of 5.5 to 7.0. The excess volume of the solution is discharged through the column bottom tube, its pH is controlled by potentiometric method, and the content of the marker substance is controlled by spectrophotometry. In this improved measurement embodiment, no acid solution is added.

[0151] 5. Pour purified water into the column in a total weight that is 5 to 10 times the weight of the PMSPH sample.

[0152] 6. After keeping the purified water in the column for 1.5 to 24 hours, drain it through the bottom tube of the column.

[0153] 7. Check the pH and content of the marker substance in the UV and visible regions of the solution discharged from the column using spectrophotometry. Perform UV spectrophotometry on purified water to qualitatively evaluate the content of any type of dissolved substances in the test solution. Based on the results of UV spectrophotometry, in the case where the presence of soluble substances is confirmed, use spectrophotometry in the visible region for a calibration solution of the marker substance. In the case of using BSA, additionally treat the solution with a biuret reagent and then perform spectrophotometry on the resulting complex. Based on the results of the calculation of the amount of marker substance in the test solution, draw a balance and calculate the residual amount of marker substance by weight of PMSPH.

[0154] 8. Pour the calculated volume of 0.0001 to 0.0005 M acid solution (hydrochloric acid, sulfuric acid or citric acid, not necessarily the same as used in step 4) into the column to achieve a pH in the range of 1.0 to 2.0. Keep the mixture in the column for 0.5 to 6 hours, then add a total weight of purified water 5 to 10 times the weight of the PMSPG sample but the same weight as in step 5.

[0155] 9. After keeping the purified water in the column for 1.5 to 24 hours, drain it through the bottom tube of the column.

[0156] 10. Use UV-Vis spectrophotometry to study the pH and content of the marker substance in the solution discharged from the column. Based on the calculation results of the amount of marker substance in the test solution, plot the balance, calculate the residual amount of marker substance based on the weight of PMSPH, and calculate the supramolecular properties of PMSPH as the ratio of the weight of marker substance found in the solution in step 9 to the initial weight of marker substance loaded in step 3.

[0157] The obtained supramolecular properties were compared with data obtained in the usual way for PMSPH samples and measured using the method prepared as described above.

[0158] Example 1. Method for producing polymethylsiloxane polyhydrate having supramolecular properties of molecular capsules

[0159] 210 g of methylsilanetriol containing 94.5 g of PMS was mixed with 49.8 g of sodium hydroxide (main substance content 98.5%).

[0160] The final MeOH / PMS ratio (mol / mol) was 0.87.

[0161] After the mixture was heated, 1.79 g (0.025 mol / 1 mol of base) of sodium chloride and 280 g of water were added thereto.

[0162] Total loaded weight is 541.59 g.

[0163] The mixture was maintained at 90°C for 2 hours.

[0164] Characteristics of methylsilanetriol alkaline solution: alkalinity 3.1 mol / L; content 310.1 g / L; solution density 1.17 kg / L.

[0165] Gel formation was performed by mixing the methylsilanetriol base solution with a 3 to 3.5 M sulfuric acid solution in a volume ratio of 3 to 3.3:1.

[0166] After the gel is mature, it is crushed and first washed with a 0.01% to 0.015% sulfuric acid solution until the acidity of the solution reaches 2.5 to 4.0.

[0167] The washing is further performed with purified water until the pH of the washing water is 5.5 to 7.0 and electrolyte anions and sulfate are absent.

[0168] Results of determination of supramolecular properties of PMSPH and parameters of some steps of the method for determination of supramolecular properties according to Example 1

[0169] 1. The weighed portion of PMSPH is 20.53 g.

[0170] The dry residue was 10.03%.

[0171] The adsorption capacity of methyl orange is 2.28 mg / g; the adsorption capacity of bovine serum albumin is 1.2 mg / g.

[0172] 3. Estimated loading per unit PMSPG sample weight: methyl orange 46.8084 mg, bovine serum albumin 24.636 mg.

[0173] 4. The weight of washed methyl orange was 0.4208 mg (0.9%).

[0174] The weight of washed BSA was 0.223 mg (0.91%).

[0175] 5. The weight of the water poured in is 102.65 g.

[0176] 6. Solution exposure is 9 hours.

[0177] 7. The weight of washed methyl orange was 1.3294 mg (2.84%).

[0178] The weight of washed BSA was 0.3856 mg (1.57%).

[0179] 10. The weight of washed methyl orange was 36.2083 mg (77.35%).

[0180] The weight of washed BSA was 19.6049 mg (79.58%).

[0181] The weight of methyl orange held in complex with PMSPH was 8.8499 mg (18.91%).

[0182] The weight of BSA held in complex with PMSPH was 4.4225 mg (17.95%).

[0183] As can be seen from the data provided in Example 1, the restriction capacity of PMSPH for methyl orange is 77% and the restriction capacity for bovine serum albumin is 79%. That is, in step 4 of the method for testing supramolecular properties, the function of the acid is to "lock" the substance (methyl orange or bovine serum albumin) in the volume of PMSPH. Even after the complex is kept in 5 times the amount of water (steps 5 to 7), trace amounts of the "locked" substance are present in the washing solution, which also confirms the fact of "locking". Adding a portion of the acid solution to the complex in step 8 plays a key role and "unlocks" the substance from the complex, they are freely washed out by water and measured in the solution (steps 9 to 10). The properties of the obtained PMSPH characterize the product from the perspective of the presence of supramolecular properties that are not present in PMSPH obtained in the usual way (Examples 2 to 3).

[0184] Example 2. Production of polymethylsiloxane polyhydrate in the usual manner and testing of supramolecular properties (embodiment using sodium hydroxide)

[0185] 210 g of methylsilanetriol containing 94.5 g of PMS was mixed with 51.5 g of sodium hydroxide (main substance content 98.5%).

[0186] The final MeOH / PMS ratio (mol / mol) was 0.9.

[0187] After the mixture was heated, 290 g of water was added thereto.

[0188] Total loaded weight is 551.5 g.

[0189] The mixture was maintained at 90°C for 2 hours.

[0190] Characteristics of methylsilanetriol alkaline solution: alkalinity 3.2 mol / L; content 286 g / L; solution density 1.19 kg / L.

[0191] Gelation, washing and washing control were performed according to the same parameters and criteria as in Example 1.

[0192] Results of determination of supramolecular properties of PMSPH and parameters of some steps of the method for determination of supramolecular properties according to Example 2

[0193] 1. The weighed portion of PMSPH is 21.39 g.

[0194] The dry residue was 8.84%.

[0195] The adsorption capacity of methyl orange is 1.12 mg / g; the adsorption capacity of bovine serum albumin is 0.77 mg / g.

[0196] 3. Estimated loading per PMSPG sample weight: Methyl orange 23.957 mg, BSA 16.47 mg.

[0197] 4. The weight of washed methyl orange was 0.5057 mg (2.11%).

[0198] The weight of the washed BSA was 0.2754 mg (1.67%).

[0199] 5. The weight of the water poured in is 171.12 g.

[0200] 6. The exposure time of the solution is 4 hours.

[0201] 7. The weight of washed methyl orange was 17.3233 mg (72.31%).

[0202] The weight of washed BSA was 13.456 mg (81.7%).

[0203] 10. The weight of washed methyl orange was 5.0956 mg (21.27%).

[0204] The weight of washed BSA was 2.426 mg (14.73%).

[0205] The weight of methyl orange retained in complex with PMSPG was 1.0324 mg (4.31%).

[0206] The weight of BSA retained in complex with PMSPG was 0.3126 mg (1.90%).

[0207] Example 3. Production of polymethylsiloxane polyhydrate in the usual manner and testing of supramolecular properties (embodiment using potassium hydroxide)

[0208] 200 g of methylsilanetriol containing 90 g of PMS was mixed with 66.9 g of potassium hydroxide (main substance content 99.0%).

[0209] The final MeOH / PMS ratio (mol / mol) was 0.88.

[0210] After the mixture was heated, 270 g of water was added thereto.

[0211] Total loaded weight is 536.9 g.

[0212] The mixture was maintained at 90°C for 2 hours.

[0213] Characteristics of methylsilanetriol alkaline solution: alkalinity 3.1 mol / L; content 323 g / L; solution density 1.176 kg / L.

[0214] Gelation, washing and washing control were performed according to the same parameters and criteria as in Example 1.

[0215] Results of determination of supramolecular properties of PMSPH and parameters of some steps of the method for determination of supramolecular properties according to Example 3

[0216] 1. The weighed portion of PMSPH is 19.94 g.

[0217] The dry residue was 10.13%.

[0218] The adsorption capacity of methyl orange was 1.38 mg / g, and that of bovine serum albumin was 0.91 mg / g.

[0219] 3. Estimated loading per PMSPG sample weight: Methyl orange 27.5172 mg, BSA 18.1454 mg.

[0220] 4. The weight of washed methyl orange was 0.8916 mg (3.24%).

[0221] The weight of washed BSA was 0.3846 mg (2.12%).

[0222] 5. The weight of the water poured in is 159.52 g.

[0223] 6. Solution exposure was 17 hours.

[0224] 7. The weight of washed methyl orange was 21.7881 mg (79.18%).

[0225] The weight of washed BSA was 14.3221 mg (78.93%).

[0226] 10. The weight of washed methyl orange was 3.9267 mg (14.27%).

[0227] The weight of washed BSA was 2.8434 mg (15.67%).

[0228] The weight of methyl orange retained in complex with PMSPG was 0.9108 mg (3.31%).

[0229] The weight of BSA retained in complex with PMSPG was 0.5953 mg (3.28%).

[0230] As is evident from Examples 2 and 3, most of the material is washed out during the initial acidification of the solution (step 7). The possible loading of the marker material on PMSPH is much lower than on the product of the invention. It can therefore be concluded that the process of the invention for producing polymethylsiloxane polyhydrate makes it possible to produce a product having novel properties, obtained by carrying out the process for producing said product according to the sequence of steps proposed and described according to the invention.

[0231] Examples 4 to 50. Method for producing structures using a mixture of sodium or potassium chloride or sulfate or carbonate and an alkaline solution of methylsilanetriol

[0232] Considering the low cost of chlorides, sulfates, and carbonates of sodium or potassium, the authors conducted a series of experiments to study the supramolecular properties of polymethylsiloxane polyhydrates with the addition of different amounts of electrolytes in the step of obtaining an alkaline solution of methylsilanetriol.

[0233] Gelation, washing and washing control were performed according to the same parameters and criteria as in Example 1.

[0234] The structures according to Examples 4 to 50 were obtained according to the method given in Example 1.

[0235] The main parameters and supramolecular properties when using these electrolytes are shown in Table 2.

[0236] The data on the parameters of supramolecular properties in the step of determining the amount of marker substances washed out are not linearly dependent on the amount of electrolyte added in the step of producing the methylsilanetriol alkaline solution. According to the authors, this dependence is multiparametric. From the data presented, it is clear that PMSPH is able to "conditionally lock" 74% to 85% of the marker substances and to release them as soon as the acidity of the system decreases, which is valuable when using this property of the product in medicine, veterinary medicine and various industries.

[0237] Examples 51 to 96. Methods for producing structures 51 to 96 using mixtures of various electrolytes and alkaline solutions of methylsilanetriol

[0238] The structures according to Examples 51 to 96 are obtained according to the method given in Example 1.

[0239] The main parameters and supramolecular properties when using these electrolytes are shown in Table 2.

[0240] The adsorption capacity values ​​of the samples obtained by the method of the present invention and described in the examples are shown in Table 2.

[0241] The low-molecular-weight electrolyte in the solution formed in the hydrogel network space inhibits the dissociation of groups (OH(-), OMe(-) and Me(+)) in the polymer network, increases the density of the electrical double layer, and therefore the diffusion of the solvent (alkaline aqueous solution of methylsilanetriol) in the gel mass is reduced. This facilitates the occurrence of polycondensation reactions in the newly created space without excessive winding of the three-dimensional coil, reduces the isolation of Me(+) ions formed by polycondensation, which allows the reaction of replacing OH groups with OME groups (EV Vorobyeva, NP Krutko, Polymer complexes in aqueous and saline environments, National Academy of Sciences of Belarus, Institute of General and Inorganic Chemistry, Minsk, Belaruskaya Navuka, 2010, 175 pages).

[0242] The authors emphasize that the present invention has developed a unique new method for producing a methylsilanetriol alkaline solution which contains dimer molecules and differs from the known potassium or sodium methylsilicates in their properties and characteristics.

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[0244]

[0245]

[0246]

[0247]

[0248]

[0249]

[0250]

[0251] General conclusions

[0252] It has been experimentally proven that the methylsilanetriol alkaline solution produced by the authors of the present invention is not described in the literature and does not belong to substances such as potassium methyl silicate or sodium methyl silicate.

[0253] In the case of MeOH / PMS molar ratios ranging from 0.84 to 0.9, the process of dissolving methylsilanetriol in base yielded a set of fully dimerized molecules.

[0254] A set of dimers of standard composition can be obtained from dehydrated methylsilanetriol.

[0255] It has been determined that during the polycondensation process, a low molecular weight fraction is formed which "blocks" the final product. It has also been found that substitution reactions may be difficult to occur for this reason.

[0256] The addition of electrolytes to the methylsilanetriol alkaline solution promoted the production of PMSPH with supramolecular properties of molecular capsules.

[0257] In the process of producing PMSPH according to the described scheme, one of its characteristic properties is the adsorption capacity, which makes the substance also act as an adsorbent containing polymethylsiloxane polyhydrate.

[0258] The structural formula of PMSPH presents a dimer with variable composition as the basic unit, with a polyhydrate shell, and the mass average molecular mass tends to infinity.

Claims

1. A method for producing a polymethylsiloxane polyhydrate having supramolecular properties of a molecular capsule, wherein a metasil solution is polycondensed with an acid, the metasil solution being obtained by mixing at a temperature above 90° C. in a ratio of 0.84 mol to 0.9 mol of a base per 1 mol of polymethylsiloxane contained in methylsilanetriol, and adding an electrolyte in an amount of 0.025 mol to 0.1 mol per mol of the base.

2. The method of claim 1, wherein the electrolyte is a chloride, bromide, iodide, nitrate, nitrite, carbonate, sulfate, sulfite, acetate, oxalate, succinate, formate or citrate of lithium, sodium, potassium or ammonium, or a mixture of said salts.

3. The process according to claim 1, wherein the base is sodium hydroxide or potassium hydroxide.

4. A polymethylsiloxane polyhydrate having supramolecular properties produced by the method of claim 1, wherein the chemical formula of the polymethylsiloxane polyhydrate is: ， in For products in gel form, q typically ranges from 60 to 92. For products in paste form, q typically ranges from 89 to 134. For products in suspension form, q typically ranges from 133 to 241. An adsorbent comprising the polymethylsiloxane polyhydrate according to claim 4.

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