阅读说明：本技术 化合物、液晶组合物以及显示装置 (Compound, liquid crystal composition and display device ) 是由 贾刚刚 霍学兵 王雪岚 于 2020-12-25 设计创作，主要内容包括：本申请涉及液晶领域,公开一种化合物、液晶组合物以及显示装置。该化合物具有式(I)的结构：该化合物可作为一种新型的液晶化合物,使用该化合物的液晶组合物具有较好的显示效果。(The application relates to the field of liquid crystal, and discloses a compound, a liquid crystal composition and a display device. The compound has the structure of formula (I):)

1. A compound having the structure of formula (I):

wherein R is₂In the presence or absence of R₂When present, R₁、R₂Each independently selected from hydrogen, fluorine, chlorine, C1-C15 alkyl, C1-C15 alkoxy, C3-C15 cycloalkyl, C2-C15 alkenyl, C2-C15 alkenyloxy, C2-C15 alkynyl, ether group, thioether group, ester group, cyano group, cyanato group, thiocyano group or isothiocyanato group;

Z₁、Z₂each independently present or absent; z₁、Z₂Each independently of the other, Z₁、Z₂Each independently selected from linear C1-C5 alkyl, linear C2-C5 alkenyl, linear C2-C5 alkynyl, ester group and ether group;

the hydrogen in the C1-C15 alkyl, C1-C15 alkoxy, C3-C15 cycloalkyl, C2-C15 alkenyl, C2-C15 alkenyloxy, C2-C15 alkynyl, ether, thioether, ester, cyano, cyanato, thiocyano, isothiocyanato, straight-chain C1-C5 alkyl, straight-chain C2-C5 alkenyl and straight-chain C2-C5 alkynyl is unsubstituted, or part or all of the hydrogen is substituted by at least one of fluorine and chlorine;

each independently selected from the group consisting of alicyclic, aryl or heteroaryl, wherein the hydrogens on the alicyclic, aryl or heteroaryl groups are unsubstituted, or some or all of the hydrogens are replaced with fluorine;

m, n each independently represent 0, 1 or 2, and m + n.gtoreq.1.

2. The compound of claim 1,each independently selected from:

3. the compound of claim 1, wherein Z is₁、Z₂Each independently selected from-CH₂-、-CH₂-CH₂-、-(CH₂)₃-、-(CH₂)₄-、-CH＝CH-、-C≡C-、-COO-、-OOC-、-CF₂O-、-OCH₂-、-CH₂O-、-OCF₂-、-CF₂-CH₂-、-CH₂-CF₂-、-C₂F₄-or-CF ═ CF.

4. The compound of claim 1, wherein the compound of formula (I) is selected from the group consisting of:

5. a liquid crystal composition comprising 0.5 to 50% by weight of a compound of formula (I) as claimed in any one of claims 1 to 4.

6. The liquid crystal composition of claim 5, further comprising 30% to 99% by weight of a compound represented by formula (II):

wherein R is₃And R₄Each independently selected from hydrogen, halogen, C1-C15 alkyl, C1-C15 alkoxy, C2-C15 alkenyl, C2-C15 alkynyl, ether group, ester group or cyano; hydrogen in the C1-C15 alkyl, C1-C15 alkoxy, C2-C15 alkenyl, C2-C15 alkynyl, ether group, ester group and cyano is unsubstituted, or partial hydrogen or all hydrogen is replaced by at least one of fluorine and chlorine;

Z₃selected from an alkylene bridge, an alkyleneoxy bridge, an alkenylene bridge, an alkynyl bridge, an ester bridge, or an alkyleneoxy bridge; wherein hydrogen on the alkylene bridge, alkyleneoxy bridge, alkenylene bridge, alkynyl bridge, ester bridge or alkyleneoxy bridge is unsubstituted or part or all of the hydrogen is substituted by at least one of fluorine and chlorine;

each independently selected from the group consisting of alicyclic, aryl or heteroaryl, wherein the hydrogens on the alicyclic, aryl or heteroaryl groups are unsubstituted, or some or all of the hydrogens are replaced with fluorine;

p and q are each independently selected from 0, 1 or 2.

7. The liquid crystal composition of claim 5, further comprising 0.01 to 1% by weight of at least one of a chiral dopant and 0.01 to 20% of a polymeric monomer director.

8. A display device comprising the liquid crystal composition according to any one of claims 5 to 7.

Technical Field

The invention relates to the field of liquid crystal display, in particular to a compound, a liquid crystal composition and a display device.

Background

Depending on the display mode, the liquid crystal display device is classified into the following modes: twisted Nematic (TN) mode, Super Twisted Nematic (STN) mode, in-plane mode (IPS), Vertical Alignment (VA) mode. The liquid crystal composition is required to have the following characteristics regardless of the display mode: chemical property, stable physical property, low viscosity, proper delta epsilon and resolution ratio delta n, and good compatibility with other liquid crystal compounds. The application discloses a compound, a liquid crystal composition and a display device, wherein the compound can be used as a novel liquid crystal compound, and the liquid crystal composition using the compound has a good display effect.

Disclosure of Invention

The application discloses a compound, a liquid crystal composition and a display device, wherein the compound can be used as a novel liquid crystal compound, and the liquid crystal composition using the compound has a good display effect.

In order to achieve the purpose, the application provides the following technical scheme:

a compound having the structure of formula (I):

wherein R is₂In the presence or absence of R₂When present, R₁、R₂Each independently selected from hydrogen, fluorine, chlorine, C1-C15 alkyl, C1-C15 alkoxy, C3-C15 cycloalkyl, C2-C15 alkenyl, C2-C15 alkenyloxy, C2-C15 alkynyl, ether group, thioether group, ester group, cyano group, cyanato group, thiocyano group or isothiocyanato group;

Z₁、Z₂each independently present or absent; z₁、Z₂Each independently of the other, Z₁、Z₂Each independently selected from linear C1-C5 alkyl, linear C2-C5 alkenyl, linear C2-C5 alkynyl, ester group and ether group;

the hydrogen in the C1-C15 alkyl, C1-C15 alkoxy, C3-C15 cycloalkyl, C2-C15 alkenyl, C2-C15 alkenyloxy, C2-C15 alkynyl, ether, thioether, ester, cyano, cyanato, thiocyano, isothiocyanato, straight-chain C1-C5 alkyl, straight-chain C2-C5 alkenyl and straight-chain C2-C5 alkynyl is unsubstituted, or part or all of the hydrogen is substituted by at least one of fluorine and chlorine;

each independently selected from the group consisting of alicyclic, aryl or heteroaryl, wherein the hydrogens on the alicyclic, aryl or heteroaryl groups are unsubstituted, or some or all of the hydrogens are replaced with fluorine;

m, n each independently represent 0, 1 or 2, and m + n.gtoreq.1.

Further, the air conditioner is provided with a fan,each independently selected from:

further, Z is₁、Z₂Each independently selected from-CH₂-、-CH₂-CH₂-、-(CH₂)₃-、-(CH₂)₄-、 -CH＝CH-、-C≡C-、-COO-、-OOC-、-CF₂O-、-OCH₂-、-CH₂O-、-OCF₂-、-CF₂-CH₂-、 -CH₂-CF₂-、-C₂F₄-or-CF ═ CF.

Further, the compound represented by the formula (I) is selected from:

a liquid crystal composition comprising from 0.5% to 50% by weight of a compound as described herein.

Further, the liquid crystal composition also comprises 30-99% by weight of a compound shown as a formula (II):

wherein R is₃And R₄Each independently selected from hydrogen, halogen, C1-C15 alkyl, C1-C15 alkoxy, C2-C15 alkenyl, C2-C15 alkynyl, ether group, ester group or cyano; hydrogen in the C1-C15 alkyl, C1-C15 alkoxy, C2-C15 alkenyl, C2-C15 alkynyl, ether group, ester group and cyano is unsubstituted, or partial hydrogen or all hydrogen is replaced by at least one of fluorine and chlorine;

Z₃selected from an alkylene bridge, an alkyleneoxy bridge, an alkenylene bridge, an alkynyl bridge, an ester bridge, or an alkyleneoxy bridge; wherein hydrogen on the alkylene bridge, alkyleneoxy bridge, alkenylene bridge, alkynyl bridge, ester bridge or alkyleneoxy bridge is unsubstituted or part or all of the hydrogen is substituted by at least one of fluorine and chlorine;

each independently selected from the group consisting of alicyclic, aryl or heteroaryl, wherein the hydrogens on the alicyclic, aryl or heteroaryl groups are unsubstituted, or some or all of the hydrogens are replaced with fluorine;

p and q are each independently selected from 0, 1 or 2.

Further, the liquid crystal composition also comprises 0.01-1% of chiral dopant and 0.01-20% of at least one of polymer monomer orientation agent.

A display device comprising a liquid crystal composition as in the present application.

By adopting the technical scheme of the application, the beneficial effects are as follows:

the compound shown in the formula (I) is a novel liquid crystal compound, comprises the compound shown in the formula (I), can be a positive liquid crystal composition or a negative liquid crystal composition, has a wide liquid crystal phase temperature range, a high clearing point and low viscosity, has a proper refractive index anisotropy constant, can improve the performance of a liquid crystal composition material and a display, and has an important significance for realizing quick response of the display.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

It should be noted that: in the present application, all embodiments and preferred methods mentioned herein can be combined with each other to form new solutions, if not specifically stated. In the present application, all the technical features mentioned herein as well as preferred features may be combined with each other to form new technical solutions, if not specifically stated. In the present application, percentages (%) or parts refer to percent by weight or parts by weight relative to the composition, unless otherwise specified. In the present application, the components referred to or the preferred components thereof may be combined with each other to form new embodiments, if not specifically stated. In this application, unless otherwise stated, the numerical range "a-b" represents a shorthand representation of any combination of real numbers between a and b, where a and b are both real numbers. For example, a numerical range of "6 to 22" means that all real numbers between "6 to 22" have been listed herein, and "6 to 22" is simply a shorthand representation of the combination of these values. The "ranges" disclosed herein may be in the form of lower limits and upper limits, and may be one or more lower limits and one or more upper limits, respectively. In the present application, the individual reactions or process steps may be performed sequentially or in sequence, unless otherwise indicated. Preferably, the reaction processes herein are carried out sequentially.

Unless otherwise defined, technical and scientific terms used herein have the same meaning as is familiar to those skilled in the art. In addition, any methods or materials similar or equivalent to those described herein can also be used in the present application.

In a first aspect, the present application provides a compound having the structure of formula (I):

wherein R is₂In the presence or absence of R₂When present, R₁、R₂Each independently selected from hydrogen, fluorine, chlorine, C1-C15 alkyl, C1-C15 alkoxy, C3-C15 cycloalkyl, C2-C15 alkenyl, C2-C15 alkenyloxy, C2-C15 alkynyl, ether group, thioether group, ester group, cyano group, cyanato group, thiocyano group or isothiocyanato group;

Z₁、Z₂each independently present or absent; z₁、Z₂Each independently of the other, Z₁、Z₂Each independently selected from linear C1-C5 alkyl, linear C2-C5 alkenyl, linear C2-C5 alkynyl, ester group and ether group;

the hydrogen in the C1-C15 alkyl, C1-C15 alkoxy, C3-C15 cycloalkyl, C2-C15 alkenyl, C2-C15 alkenyloxy, C2-C15 alkynyl, ether, thioether, ester, cyano, cyanato, thiocyano, isothiocyanato, straight-chain C1-C5 alkyl, straight-chain C2-C5 alkenyl and straight-chain C2-C5 alkynyl is unsubstituted, or part or all of the hydrogen is substituted by at least one of fluorine and chlorine;

m, n each independently represent 0, 1 or 2, and m + n.gtoreq.1.

The compound shown in the formula (I) is a novel liquid crystal compound, comprises the compound shown in the formula (I), can be a positive liquid crystal composition or a negative liquid crystal composition, has a wide liquid crystal phase temperature range, a high clearing point and low viscosity, has a proper refractive index anisotropy constant, can improve the performance of a liquid crystal composition material and a display, and has an important significance for realizing quick response of the display.

Wherein Z is₁、Z₂Each independently present or absent as a bridge. When Z is₁、Z₂Each independently of the other, Z₁、Z₂Each independently selected from linear C1-C5 alkyl, linear C2-C5 alkenyl, linear C2-C5 alkynyl, ester group and ether group. At this time，Z₁、Z₂Each independently selected from an alkylene bridge, an alkyleneoxy bridge, an alkenylene bridge, an alkynyl bridge, an ester bridge, or an alkyleneoxy bridge; wherein hydrogen on the alkylene bridge, alkyleneoxy bridge, alkenylene bridge, alkynyl bridge, ester bridge or alkyleneoxy bridge is unsubstituted or part or all of hydrogen is substituted by at least one of fluorine and chlorine.

In one embodiment of the present application,each independently selected from:

in one embodiment of the present application, Z is₁、Z₂Each independently selected from-CH₂-、-CH₂-CH₂-、 -(CH₂)₃-、-(CH₂)₄-、-CH＝CH-、-C≡C-、-COO-、-OOC-、-CF₂O-、-OCH₂-、-CH₂O-、 -OCF₂-、-CF₂-CH₂-、-CH₂-CF₂-、-C₂F₄-or-CF ═ CF.

The compound of formula (I) is selected from:

in a second aspect, the present application provides a liquid crystal composition comprising from 0.5% to 50% by weight of a compound of formula (I) as described herein.

The liquid crystal composition has the advantages of wide temperature range of liquid crystal phase, high clearing point, low viscosity and proper refractive index anisotropy constant, can improve the performance of liquid crystal composition materials and displays, and has important significance for realizing quick response of the displays.

In the examples of the present application, the mass ratio of the compound represented by the formula (I) in the liquid crystal composition may be, for example, 0.5%, 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, or 50%.

In one embodiment of the present application, the liquid crystal composition further comprises 30% to 99% by weight of a compound represented by formula (II):

wherein R is₃And R₄Each independently selected from hydrogen, halogen, C1-C15 alkyl, C1-C15 alkoxy, C2-C15 alkenyl, C2-C15 alkynyl, ether group, ester group or cyano; hydrogen in the C1-C15 alkyl, C1-C15 alkoxy, C2-C15 alkenyl, C2-C15 alkynyl, ether group, ester group and cyano is unsubstituted, or partial hydrogen or all hydrogen is replaced by at least one of fluorine and chlorine;

Z₃selected from an alkylene bridge, an alkyleneoxy bridge, an alkenylene bridge, an alkynyl bridge, an ester bridge, or an alkyleneoxy bridge; wherein hydrogen on the alkylene bridge, alkyleneoxy bridge, alkenylene bridge, alkynyl bridge, ester bridge or alkyleneoxy bridge is unsubstituted or part or all of the hydrogen is substituted by at least one of fluorine and chlorine;

each independently selected from the group consisting of alicyclic, aryl or heteroaryl, wherein the hydrogens on the alicyclic, aryl or heteroaryl groups are unsubstituted, or some or all of the hydrogens are replaced with fluorine;

p and q are each independently selected from 0, 1 or 2.

In the examples of the present application, the mass ratio of the compound represented by the formula (II) in the liquid crystal composition may be, for example, 0.5%, 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, or 50%.

In one embodiment of the present application,each independently selected from:

in one embodiment of the present application, the liquid crystal composition further comprises at least one of a chiral dopant in an amount of 0.01 to 1% by weight and a polymer monomer alignment agent in an amount of 0.01 to 20% by weight.

Among them, the chiral dopant may be, for example:

the polymeric monomer director (for alignment) may be, for example:

the preparation method of the liquid crystal composition of the present application includes, but is not limited to, the following: (1) heating, mixing and stirring various monomer liquid crystal compounds uniformly, and filtering to obtain a liquid crystal material; (2) dissolving various monomer liquid crystal compounds by using a solvent, uniformly mixing, and then extracting the solvent under a vacuum condition to obtain a liquid crystal material; (3) various monomer liquid crystal compounds are uniformly mixed by using oscillation mixing or ultrasonic mixing and the like, and then the liquid crystal material is obtained by filtering. The proportion of each monomer liquid crystal material is prepared according to the specific display performance requirement. The mixed liquid crystal material can be prepared by the method.

In a second aspect, the present application provides a display device comprising a liquid crystal composition as in the present application.

The display device may be a liquid crystal display device or an electro-optical display device, and specifically, a device used for display such as a TN display, a VA display, an IPS display, or a blue phase display.

The display device comprises a liquid crystal display panel, wherein the liquid crystal display panel comprises a first substrate and a second substrate which are arranged in a manner of opposite to each other, and a liquid crystal layer filled between the first substrate and the second substrate, and the liquid crystal layer contains the liquid crystal composition.

Synthesis of intermediate I

Dissolving 220g of dibutanoic acid with 600ml of toluene, adding 5g of p-toluenesulfonic acid, refluxing for 5h-6h, washing with water to neutralize to obtain a toluene solution of a compound 2, adding 200ml of ethanol and 5g of Pd/C as a hydrogenation catalyst, filtering palladium carbon after hydrogen absorption, and concentrating through a column to obtain a compound 3;

adding a Jones reagent into the compound 3 to oxidize the compound 3 to obtain a compound 4;

dissolving 200g of the compound 4 in Tetrahydrofuran (THF), adding 60g of ethylene glycol by using cationic resin as a catalyst, heating for reacting for 4-6h, and treating a reaction solution to obtain a compound 5;

reacting the compound 5 with propyl magnesium bromide in tetrahydrofuran solution, and dehydrating by using p-toluenesulfonic acid after acidolysis to obtain a compound 6;

the compound 6 is hydrogenated by palladium carbon to obtain a compound 7, and then hydrochloric acid is used for deprotection to obtain an intermediate I.

Example 1

Compound S12:

the synthetic route of the compound is as follows:

preparing a Grignard reagent from 200g of 3, 5-difluorobromobenzene and 24g of magnesium metal in THF, dropwise adding 230g of an intermediate I, carrying out reflux reaction for 3 hours, adding dilute hydrochloric acid for acidolysis under an ice bath condition, extracting an organic phase from toluene, adding 5g of p-toluenesulfonic acid into the organic phase, carrying out reflux dehydration for 4-5 hours, adsorbing by silica gel, adding 5g of palladium-carbon, carrying out normal pressure hydrogenation, filtering the palladium-carbon after GC detection hydrogenation reaction is finished, and concentrating a reaction solution to obtain a compound 8.

Taking 30g of the compound 8, dissolving the compound with THF, then cooling to-60-70 ℃, dropwise adding 0.1mol of n-BuLi solution, reacting for 1h under controlled temperature, dropwise adding 25g of dibromodifluoromethane, reacting for 1h under controlled temperature, heating to room temperature, carrying out acidolysis, extracting an organic phase with toluene, neutralizing, and carrying out spin drying to obtain a compound 9;

45g of the compound 9 is prepared by taking DMF as a solvent, adding 20g of sodium carbonate, 15g of 3,4, 5-trifluorophenol and 10g of water, carrying out reflux reaction for 12h, extracting a reaction solution with toluene, neutralizing, spin-drying, and recrystallizing with ethanol toluene to obtain a product, namely a compound S12.

Compound S12 assay:

and (3) nuclear magnetic detection results:¹H NMR(400MHz，Chloroform-d)δ：7.20(s，2H)， 6.89(q，2H)，6.54(d，2H)，3.32(m，3H)，3.05(m，4H)，2.75(q，2H),2.03 (m，1H)，1.27(m，4H)，0.90(t，3H)

mass spectral data m/z: m +508

Example 2

Compound S14:

the synthetic route of the compound is as follows:

compound 8 was prepared according to the same route as for the preparation of compound S12;

dissolving 320g of compound 8 in THF600ml, dropwise adding 1.2mol of n-BuLi solution at-60 ℃, reacting for 1h, dropwise adding 150g of trimethyl borate, reacting for 1h at controlled temperature, heating to room temperature, carrying out acidolysis with hydrochloric acid, and filtering to obtain a compound 10;

360g of compound 10, 4-ethoxy-2, 3-difluorobromobenzene 270g, toluene 800ml, ethanol 600ml and water 500ml, stirring and refluxing for 6h, filtering, extracting filter residue with toluene, combining organic phases, neutralizing and concentrating to obtain a crude product, and recrystallizing with ethanol and toluene to obtain the final product, compound S14.

Compound S14 assay:

nuclear magnetic detection data:¹H NMR(400MHz，Chloroform-d)δ：7.45(m，2H)， 7.20(s，2H)，7.09(m，2H)，4.06(t，2H)，3.33(m，3H)，3.03(m，4H)， 2.75(q，2H)，2.03(m，1H),1.76(m，2H)，1.45(m，2H)，1.28(m，4H)， 0.90(t，6H)

mass spectral data m/z: m + 496.

Example 3

Compound S15:

the synthetic route of the compound is as follows:

160g of bromobenzene and 24g of magnesium metal are prepared into a Grignard reagent in THF, 230g of an intermediate I is dropwise added, after reflux reaction is carried out for 3 hours, dilute hydrochloric acid is added for acidolysis under an ice bath condition, toluene is used for extracting an organic phase, 5g of p-toluenesulfonic acid is added into the organic phase, reflux dehydration reaction is carried out for 4 to 5 hours, silica gel adsorption is carried out, 5g of palladium-carbon is added, normal pressure hydrogenation is carried out, after GC detection hydrogenation reaction is finished, the palladium-carbon is filtered, and reaction liquid is concentrated to obtain a compound 11;

reacting the compound 11 with NBS with 1.5 times of equivalent in carbon tetrachloride at room temperature to obtain a compound 12;

300g of the compound 12, 4-butoxy-2, 3-difluorobromobenzene 270g, toluene 800ml, ethanol 600ml and water 500ml, stirring and refluxing for 6h, filtering, extracting filter residue with toluene, combining organic phases, neutralizing and concentrating to obtain a crude product, and recrystallizing with ethanol and toluene to obtain the final product compound S15.

Compound S15 assay:

and (3) nuclear magnetic detection results:¹H NMR(400MHz，Chloroform-d)δ：7.43(m，1H)， 7.36(m，4H)，7.20(s，2H)，7.08(m，1H)，4.06(t，2H)，3.33(m，3H)， 3.04(m，4H)，2.75(q，2H)，2.03(m，1H),1.76(m，2H)，1.45(m，2H)， 1.28(m，4H)，0.90(t，6H)

mass spectral data m/z: and M + 460.

The preparation of the above compounds is merely illustrative, and other compounds referred to herein can be performed by reference to the preparation of the compounds provided in examples 1-3. In the preparation process, raw materials in the product can be correspondingly replaced according to the target product.

Example 4

This example is a liquid crystal composition whose composition of the compound monomers is shown in table 1.

TABLE 1

Example 5

This example is a liquid crystal composition whose composition of the compound monomers is shown in Table 2.

TABLE 2

The liquid crystal compositions of example 4 and example 5 were tested for clearing point Cp, optical anisotropy Δ n, and dielectric constant anisotropy Δ Σ, respectively, and the test results are shown in table 3.

The optical anisotropy test method comprises the following steps: the measurement was carried out at 25 ℃ and 589nm wavelength using an Abbe refractometer. And rubbing the surface of the main prism in the same direction, and dropping the sample on the main prism after rubbing. Refractive index n₁₁Measuring when the polarization direction is parallel to the rubbing direction; refractive index n_⊥Measuring when the polarization direction is vertical to the friction direction; optical anisotropy Deltan throughFormula Δ n ═ n₁₁-n_⊥And (6) calculating.

The dielectric anisotropy was measured as follows: the measurements were carried out using a Hewlett packard model HP4284 a. The dielectric constant Σ of the liquid crystal molecules in the axial direction was measured at 25 ℃₁₁And dielectric constant sigma in the minor axis direction of liquid crystal molecules_⊥The dielectric anisotropy is represented by the formula Δ ∑₁₁-∑_⊥And (6) calculating.

TABLE 3

Serial number	Clearing Point/. deg.C	Optical anisotropy	Anisotropy of dielectric constant
				Example 4	80	0.1	4.3
Example 5	95	0.102	-5.5

The liquid crystal composition prepared by the compound can obtain a positive liquid crystal composition and a negative liquid crystal composition by adjusting the proportion of the compound, the obtained liquid crystal composition has a high clearing point which can reach more than 80, and the optical anisotropy and the dielectric constant anisotropy can meet the display requirements of a liquid crystal display panel, so that a novel optional compound is provided for the development of a VA type display.

It will be apparent to those skilled in the art that various changes and modifications may be made in the embodiments of the present application without departing from the spirit and scope of the application. Thus, if such modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is intended to include such modifications and variations as well.