The present disclosure generally relates to glass articles with a porosity-graded layer and methods of making the same, particularly such glass articles with antireflective (AR) properties, such as low reflectance at normal, near-normal and wide angles up to 60 degrees.
Anti-reflection surfaces are used in display devices such as LCD screens, tablets, smartphones, OLEDs and touch screens to avoid or reduce specular reflection of ambient light. Reduction of specular reflection is often a desired property in touch-sensitive electronic devices, electronic ink readers, electronic whiteboards, and other portable LCD panels, especially when these devices are used in various lighting conditions. Other electronic devices that employ schemes to reduce specular reflection include optical instruments, automotive interior displays, optical lenses, laptop computers, and other electronic display devices. Further, many of these display devices require anti-reflection properties for multiple users and observers, many of which are located at non-acute incident angles.
Typically, the cover substrates employed in these devices exhibit anti-reflection properties with antiglare surface, single- and multi-layer coatings. For example, a multi-layer coating structure that includes alternating high and low refractive index layers can be deposited on a substrate to imbue it with antireflective properties. However, the composition and thicknesses of each of these layers within the multi-layer structure must be carefully controlled to obtain the desired, antireflective optical properties. Further, the processes typically employed to develop these multi-layer coating structures, e.g., physical vapor deposition (PVD) and chemical vapor deposition (CVD) processes, are time- and cost-intensive. In addition, many of these multi-layer coatings can enable acceptable anti-reflective properties at normal and near-normal incident angles, but fail to deliver anti-reflective properties over a wider range of non-acute incident angles.
Other optical coating structures characterized by variable refractive index values have been used with display device substrates to achieve anti-reflective properties over a wider range of incident viewing angles. These structures have been made through various approaches, including reactive ion etching (RIE), microsphere arraying, and co-evaporative coating deposition and etching processes. However, all of these processes are time-intensive, high in cost, and usually require complex equipment and high temperature processing.
Accordingly, there is a need for antireflective articles and methods of making the same that result in articles suitable for display devices with desired antireflective properties over a wide range of incident angles. Further, there is a need for such articles that can be made with processes that are relatively low in cost and duration.
According to an aspect of the disclosure, a glass article is provided that includes: a glass substrate comprising a thickness and a first primary surface; and a porosity-graded layer that extends from the first primary surface of the substrate to a first depth within the substrate. The first depth is from about 250 nm to about 3000 nm. The porosity-graded layer comprises a plurality of pores having an average pore size from about 5 nm to 100 nm. The article comprises a single-side average reflectance of less than 9% at an incident angle of 60 degrees across a spectrum from 350 nm to 2000 nm. Further, the porosity-graded layer comprises a surface porosity at the first primary surface and a bulk porosity at the first depth, the surface porosity greater than the bulk porosity.
According to an aspect of the disclosure, a glass article is provided that includes: a glass substrate comprising a thickness and a first primary surface; and a porosity-graded layer that extends from the first primary surface of the substrate to a first depth within the substrate. The first depth is from about 250 nm to about 3000 nm. The porosity-graded layer comprises a plurality of pores having an average pore size from about 5 nm to 100 nm. The porosity-graded layer comprises a surface porosity at the first primary surface and a bulk porosity at the first depth, the surface porosity greater than the bulk porosity. Further, the porosity-graded layer comprises a refractive index as a function of depth within the substrate, nPGL(z), from the first primary surface to the first depth, given by
n
2
PGL(z)=n2substrate(1−fpore)+n2air*fpore,
where nsubstrate is the refractive index of the glass substrate, nair is the refractive index of air, and fpore is the volume fraction of the plurality of pores at the depth, z.
According to another aspect of the disclosure, a method of making a glass article is provided that includes: providing a silica-saturated solution; filtering the silica-saturated solution to remove insoluble silica particles from the silica-saturated solution and form a filtrated solution; and immersing a glass substrate comprising a thickness and a first primary surface with the filtrated solution, the immersing conducted to form a porosity-graded layer that extends from the first primary surface of the substrate to a first depth within the substrate. The silica-saturated solution comprises SiO2 gel, H2SiF6, H3BO3 or CaCl2), de-ionized H2O, and an optional amount of HCl. The first depth in the substrate is from about 250 nm to about 3000 nm. The porosity-graded layer comprises a plurality of pores having an average pore size from about 5 nm to 100 nm. Further, the porosity-graded layer comprises a surface porosity at the first primary surface and a bulk porosity at the first depth, the surface porosity greater than the bulk porosity.
Additional features and advantages will be set forth in the detailed description which follows, and will be readily apparent to those skilled in the art from that description or recognized by practicing the embodiments as described herein, including the detailed description which follows, the claims, as well as the appended drawings.
It is to be understood that both the foregoing general description and the following detailed description are merely exemplary, and are intended to provide an overview or framework to understanding the nature and character of the disclosure as it is claimed.
The accompanying drawings are included to provide a further understanding of principles of the disclosure, and are incorporated in, and constitute a part of, this specification. The drawings illustrate one or more embodiments and, together with the description, serve to explain, by way of example, principles and operation of the disclosure. It is to be understood that various features of the disclosure disclosed in this specification and in the drawings can be used in any and all combinations. By way of non-limiting examples, the various features of the disclosure may be combined with one another according to the following aspects.
These and other features, aspects and advantages of the present disclosure are better understood when the following detailed description of the disclosure is read with reference to the accompanying drawings, in which:
In the following detailed description, for purposes of explanation and not limitation, example embodiments disclosing specific details are set forth to provide a thorough understanding of various principles of the present disclosure. However, it will be apparent to one having ordinary skill in the art, having had the benefit of the present disclosure, that the present disclosure may be practiced in other embodiments that depart from the specific details disclosed herein. Moreover, descriptions of well-known devices, methods and materials may be omitted so as not to obscure the description of various principles of the present disclosure. Finally, wherever applicable, like reference numerals refer to like elements.
Ranges can be expressed herein as from “about” one particular value, and/or to “about” another particular value. When such a range is expressed, another embodiment includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another embodiment. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint.
Directional terms as used herein for example, up, down, right, left, front, back, top, bottom—are made only with reference to the figures as drawn and are not intended to imply absolute orientation.
Unless otherwise expressly stated, it is in no way intended that any method set forth herein be construed as requiring that its steps be performed in a specific order. Accordingly, where a method claim does not actually recite an order to be followed by its steps, or it is not otherwise specifically stated in the claims or descriptions that the steps are to be limited to a specific order, it is in no way intended that an order be inferred, in any respect. This holds for any possible non-express basis for interpretation, including: matters of logic with respect to arrangement of steps or operational flow; plain meaning derived from grammatical organization or punctuation; the number or type of embodiments described in the specification.
As used herein, the singular forms “a,” “an” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to a “component” includes aspects having two or more such components, unless the context clearly indicates otherwise.
As used herein, the terms “pore size,” “pore diameter,” “average pore size” and “average pore diameter” are used interchangeably to refer to an average pore size of the porosity-graded layer of the glass articles of the disclosure that is determined on a volumetric basis. The average pore size or average pore diameter is determined according to a gas adsorption method or an effective refractive index method, as understood by those of ordinary skill in the field of the disclosure.
As used herein, the term “porosity” refers to the volume fraction (%) of the plurality of pores of the porosity-graded layer at a specified location of the porosity within the layer or as an average porosity of the entire porosity-graded layer. For example, “surface porosity” refers to the porosity of the plurality of pores in the porosity-graded layer at the first primary surface of the glass substrate of the antireflective glass article. Similarly, “bulk porosity” refers to the porosity of the plurality of pores in the porosity-graded layer at the first depth of the porosity-graded layer within the substrate of the antireflective glass article. In addition, “average porosity” refers to the average porosity of the plurality of pores within the entire porosity-graded layer, i.e., as spanning from the primary surface of the substrate defining the layer to its depth within the substrate.
As used herein, the term “transmittance” refers to the percentage of incident light power in a given wavelength range of a material (e.g., article, substrate, or optical film or portion thereof). The term “reflectance” refers to the percentage of incident light power that is reflected from a material (e.g., an article, substrate, or optical film or portion thereof) over a given range of wavelengths. Transmittance and reflectance are measured using a specific line width. As used herein, “average transmittance” refers to the average amount of incident light power transmitted through a material over a defined range of wavelengths. As used herein, “average reflectance” refers to the amount of average incident optical power reflected by a material. Unless otherwise noted, the reflectance and transmittance are measured through both primary surfaces of the substrate or article and designated “double side”. In some instances, however, the reflectance and transmittance values in the disclosure are designated as “single side” to refer to these values as measured at the primary surface of the substrate having a porosity-graded layer. In these “single side” measurements, a refractive index matching oil (or other known method) is coupled to the opposing primary surface to eliminate the reflectance of this back surface.
As used herein, the “average surface roughness,” “surface roughness,” “average surface roughness (Ra),” and “surface roughness (Ra)” are used interchangeably to refer to the surface roughness of a primary surface of a substrate of an antiglare article of the disclosure. This surface roughness (Ra) is calculated by first obtaining a roughness profile, which has been filtered from raw profile data of the primary surface according to principles understood by those of ordinary skill in the field of the disclosure. With the roughness profile in hand, the surface roughness (Ra) is measured according to the following equation:
where the roughness profile contains n ordered, equally spaced points along the profile, and yi is the vertical distance from the mean line of the profile to the ith data point.
Aspects of the disclosure generally pertain to anti-reflective glass articles and methods of making the same, particularly glass articles with a porosity-graded layer and a glass substrate. These glass articles have antireflective properties, such as low reflectance and/or high transmittance at normal, near-normal and wide angles up to 60 degrees. The porosity-graded layer can have a depth from about 250 nm to about 3000 nm, and a plurality of pores having an average pore size from about 5 nm to about 100 nm. Further, the porosity-graded layer has a porosity at the surface of the substrate that exceeds the porosity of the porosity-graded layer at its depth within the substrate. In addition, the porosity of the porosity-graded layer can vary continuously from the surface of the substrate to its depth within the substrate, thus exhibiting a varying refractive index as a function of its varying porosity. A method of making these antireflective glass articles includes steps of preparing a silica-saturated solution and filtering insoluble silica particles out of it. The method also includes immersing a glass substrate in the filtrated silica-saturated solution to form a porosity-graded layer in the glass substrate. The silica-saturated solution can include SiO2 gel, H2SiF6, H3BO3 or CaCl2), de-ionized H2O, and an optional amount of HCl.
The antireflective glass articles of the disclosure, and the methods of making them, demonstrate significant advantages over conventional antireflective articles (e.g., glass substrates with multi-layer antireflective coatings) and the methods of making them. The methods of the disclosure, for example, can be employed to develop a porosity-graded layer within a glass substrate, thus resulting in the in situ formation of an antireflective article. Another advantage of the AR glass articles of the disclosure is that they can possess AR properties across a broadband spectrum (e.g., inclusive of ultraviolet, visible and infrared spectra) at normal, near-normal and wide incident angles. A further advantage of the methods of the disclosure employed to make these AR glass articles is that these methods are relatively simple, short in duration and low in cost as they include wet chemical processes that do not require expensive processing equipment or significant capital outlays. Further, these methods are not susceptible to significant environmental concerns as they can be conducted at relatively low temperatures and under non-vacuum conditions. Still further, it is believed that the methods outlined in the disclosure are robust in terms of producing AR glass articles with the desired optical properties, and amenable to easy scale up for mass production.
Referring to
As also depicted in
As further depicted in
As also depicted in
Referring again to
Referring again to the first primary surface 12 of the porosity-graded layer 30 associated with the antireflective glass article 100 depicted in
According to embodiments of the antireflective glass article 100 depicted in
According to implementations of the antireflective glass article 100 depicted in
Those with ordinary skill in the field of the disclosure will also recognize that the foregoing low reflectance and high transmittance values of the antireflective glass article 100 depicted in
Referring again to
In one embodiment of the antireflective glass article 100 depicted in
In another embodiment of the antireflective glass article 100, as shown in
In yet another embodiment, the glass substrate 10 has a bulk composition that comprises an alkali aluminosilicate glass comprising, consisting essentially of, or consisting of: about 60 mol % to about 70 mol % SiO2; about 6 mol % to about 14 mol % Al2O3; 0 mol % to about 15 mol % B2O3; 0 mol % to about 15 mol % Li2O; 0 mol % to about 20 mol % Na2O; 0 mol % to about 10 mol % K2O mol % to about 8 mol % MgO; 0 mol % to about 10 mol % CaO; 0 mol % to about 5 mol % ZrO2; 0 mol % to about 1 mol % SnO2; 0 mol % to about 1 mol % CeO2; less than about 50 ppm As2O3; and less than about 50 ppm Sb2O3, wherein 12 mol %≤Li2O+Na2O+K2O≤20 mol % and 0 mol %≤MgO+Ca≤10 mol %.
In still another embodiment, the glass substrate 10 has a bulk composition that comprises an alkali aluminosilicate glass comprising, consisting essentially of, or consisting of: about 64 mol % to about 68 mol % SiO2; about 12 mol % to about 16 mol % Na2O; about 8 mol % to about 12 mol % Al2O3; 0 mol % to about 3 mol % B3O3; about 2 mol % to about 5 mol % K2O; about 4 mol % to about 6 mol % MgO; and 0 mol % to about 5 mol % CaO, wherein: 66 mol %≤SiO2+B2O3CaO≤69 mol %; Na2O+K2O+B2O3+MgO+CaO+SrO>10 mol %; 5 mol %≤MgO+CaO+SrO≤8 mol %; (Na2O+B2O3)—Al2O3≤2 mol %; 2 mol %≤Na2O—Al2O3≤6 mol %; and 4 mol %≤(Na2O+K2O)—Al2O3≤10 mol %.
In other embodiments, the glass substrate 10 has a bulk composition that comprises SiO2, Al2O3, P2O5, and at least one alkali metal oxide (R2O), wherein 0.75>[(P2O5 (mol %)+R2O (mol %))/M2O3 (mol %)]≤1.2, where M2O3═Al2O3+B2O3. In some embodiments, [(P2O5 (mol %)+R2O (mol %))/M2O3 (mol %)]=1 and, in some embodiments, the glass does not include B2O3 and M2O3═Al2O3. The glass substrate comprises, in some embodiments: about 40 mol % to about 70 mol % SiO2; 0 mol % to about 28 mol % B2O3; about 0 mol % to about 28 mol % Al2O3; about 1 mol % to about 14 mol % P2O5; and about 12 mol % to about 16 mol % R2O. In some embodiments, the glass substrate comprises: about 40 mol % to about 64 mol % SiO2; 0 mol % to about 8 mol % B2O3; about 16 mol % to about 28 mol % Al2O3; about 2 mol % to about 12 mol % P2O5; and about 12 mol % to about 16 mol % R2O. The glass substrate 10 may further comprise at least one alkaline earth metal oxide such as, but not limited to, MgO or CaO.
In some embodiments, the glass substrate 10 has a bulk composition that is substantially free of lithium; i.e., the glass comprises less than 1 mol % Li2O and, in other embodiments, less than 0.1 mol % Li2O and, in other embodiments, 0.01 mol % Li2O, and in still other embodiments, 0 mol % L2O. In some embodiments, such glasses are free of at least one of arsenic, antimony, and barium; i.e., the glass comprises less than 1 mol % and, in other embodiments, less than 0.1 mol %, and in still other embodiments, 0 mol % of As2O3, Sb2O3, and/or BaO.
In other embodiments of the antireflective glass article 100 depicted in
According to other embodiments, the glass substrate 10 of the antireflective glass article 100 depicted in
In these embodiments of the antireflective glass article 100 depicted in
Ion exchange processes are typically carried out by immersing the glass substrate 10 in a molten salt bath containing the larger ions to be exchanged with the smaller ions in the glass. It will be appreciated by those skilled in the art that parameters for the ion exchange process, including, but not limited to, bath composition and temperature, immersion time, the number of immersions of the glass in a salt bath (or baths), use of multiple salt baths, and additional steps such as annealing, washing, and the like, are generally determined by the composition of the glass and the desired depth of layer and compressive stress of the glass as a result of the strengthening operation. By way of example, ion exchange of alkali metal-containing glasses may be achieved by immersion in at least one molten bath containing a salt such as, but not, limited to, nitrates, sulfates, and chlorides of the larger alkali metal ion. The temperature of the molten salt bath typically is in a range from about 380° C. up to about 450° C., while immersion times range from about 15 minutes up to about 16 hours. However, temperatures and immersion times different from those described above may also be used. Such ion exchange treatments, when employed with a glass substrate 10 having an alkali aluminosilicate glass composition, result in a compressive stress region 50 having a depth 52 (depth of layer) ranging from about 10 μm up to at least 50 μm with a compressive stress ranging from about 200 MPa up to about 800 MPa, and a central tension of less than about 100 MPa.
As the etching processes that can be employed to create the porosity-graded layer 30 of the antireflective glass article 100, according to some embodiments, can remove alkali metal ions from the glass substrate 10 that would otherwise be replaced by a larger alkali metal ion during an ion exchange process, a preference exists for developing a compressive stress region 50 in the antireflective glass article 100 after the formation and development of the porosity-graded layer 30. In other embodiments, a compressive stress region 50 can be developed in the glass substrate 10 prior to development of the porosity-graded layer 30 to a depth 52 sufficient to account for some loss in the depth of layer in the region 50 associated with the various treatments associated with forming the porosity-graded layer 30, as outlined below.
Referring now to
According to an implementation of the antireflective article 100 (see
n
2
PGL(z)=n2substrate(1−fpore)+n2air*fpore (1)
where substrate is the refractive index of the glass substrate 10 (e.g., nsubstrate=1.52), nair is the refractive index of air (i.e., nair=1.0), and fpore is the volume fraction of the plurality of pores at the depth, z. Further, as is evident from Equation (1) and
Referring now to
Referring again to the method 200 depicted in
Still referring to the method 200 depicted in
One of the unique advantages of the method 200 depicted in
The following examples describe various features and advantages provided by the disclosure, and are in no way intended to limit the invention and appended claims.
According to this example, Corning® Gorilla® Glass 5 glass substrates were subjected to a method of making an antireflective glass article as outlined earlier in the disclosure. In particular, a group of these glass substrates was cleaned with a detergent in an ultrasound bath at ambient temperature to an elevated temperature below boiling, e.g., from about 25° C. for about 5 minutes. Next, a silica-saturated solution was prepared with the following constituents and concentration levels: from about 3% to 5% SiO2 gel, about 1.5 to 2.0 mol/L H2SiF6, about 20 to 40 mmol/L H3BO3 or CaCl2), 0 to 0.12 mol/L HCl, and a balance of de-ionized H2O (by weight). Further, the SiO2 gel was added to the 30 to 32 wt % H2SiF6 solution with mechanical stirring at ambient temperature for about 10 to 24 hours, or until the SiO2 gel was completely dissolved and saturated within the H2SiF6 solution. Next, the specified amounts of the H3BO3 and HCl aqueous solutions were added into the SiO2-saturated, H2SiF6 solution, and then mixed by a vigorous stirring action at ambient temperature for about 10 to 30 minutes. The resulting solution was then mechanically agitated in a water bath set at from about 25° C. to about 60° C. for about 10 to 40 minutes. At this point, all of the insoluble particles from the solution were filtered to obtain a substantially clear solution. The pre-cleaned glass substrates were then immersed in the filtrated solution at about 40° C. for about 10 minutes with mechanical agitation. In addition, the immersed glass substrates were rinsed with deionized water and dried in an oven at 50° C. for 30 minutes. Upon completion of the method of this example, the treated AR glass articles (designated “Ex. 1”) exhibited a porosity-graded layer.
Referring now to
Referring now to
Referring now to
As is evident from
With regard to the conventional AR articles that comprise a multi-layer AR coating, Comp. Ex. 1A, the AR glass articles of this example demonstrate better transmittance and reflectance properties, as is evident from
The transmittance and reflectance data of the AR glass articles of Ex. 1 and glass articles of Comp. Ex. 1 from
According to this example, Corning® Gorilla® Glass 5 glass substrates were subjected to a method of making an antireflective glass article as outlined earlier in the disclosure. In particular, a group of these glass substrates was cleaned with a detergent in an ultrasound bath at ambient temperature to an elevated temperature below boiling, e.g., from about 25° C. for about 5 minutes. Next, a silica-saturated solution was prepared with the following constituents and concentration levels: from about 3% to 5% SiO2 gel, about 1.5 to 2.0 mol/L H2SiF6, about 20 to 40 mmol/L H3BO3 or CaCl2), 0 to 0.12 mol/L HCl, and a balance of de-ionized H2O (by weight). Further, the SiO2 gel was added to the 30 to 32 wt % H2SiF6 solution with mechanical stirring at ambient temperature for about 10 to 24 hours, or until the SiO2 gel was completely dissolved and saturated within the H2SiF6 solution. Next, the specified amounts of the H3BO3 and HCl aqueous solutions were added into the SiO2-saturated, H2SiF6 solution, and then mixed by a vigorous stirring action at ambient temperature for about 10 to 30 minutes. The resulting solution was then mechanically agitated in a water bath set at from about 25° C. to about 60° C. for about 10 to 40 minutes. At this point, all of the insoluble particles from the solution were filtered to obtain a substantially clear solution. The pre-cleaned glass substrates were then immersed in the filtrated solution at 25° C., 40° C. or 60° C. for about 10 minutes with mechanical agitation. In addition, the immersed glass substrates were rinsed with deionized water and dried in an oven at 50° C. for 30 minutes. Upon completion of the method of this example, each of the treated AR glass articles, as treated at an immersion temperature of 25° C., 40° C. or 60° C., exhibited a porosity-graded layer (designated “Ex. 1A”, “Ex. 1B” and “Ex. 1C”, respectively).
Referring now to
Referring now to
According to this example, Corning® Gorilla® Glass 3 glass substrates were subjected to a method of making an antireflective glass article as outlined earlier in the disclosure. In particular, a group of these glass substrates was cleaned with a detergent in an ultrasound bath at ambient temperature to an elevated temperature below boiling, e.g., from about 25° C. for about 5 minutes. Next, a silica-saturated solution was prepared with the following constituents and concentration levels: from about 3% to 5% SiO2 gel, about 1.5 to 2.0 mol/L H2SiF6, about 20 to 40 mmol/L H3BO3 or CaCl2), 0 to 0.12 mol/L HCl, and a balance of de-ionized H2O (by weight). Further, the SiO2 gel was added to the 30 to 32 wt % H2SiF6 solution with mechanical stirring at ambient temperature for about 10 to 24 hours, or until the SiO2 gel was completely dissolved and saturated within the H2SiF6 solution. Next, the specified amounts of the H3BO3 and HCl aqueous solutions were added into the SiO2-saturated, H2SiF6 solution, and then mixed by a vigorous stirring action at ambient temperature for about 10 to 30 minutes. The resulting solution was then mechanically agitated in a water bath set at from about 25° C. to about 60° C. for about 10 to 40 minutes. At this point, all of the insoluble particles from the solution were filtered to obtain a substantially clear solution. The pre-cleaned glass substrates were then immersed in the filtrated solution at about 40° C. for about 10 minutes with mechanical agitation. In addition, the immersed glass substrates were rinsed with deionized water and dried in an oven at 50° C. for 30 minutes. Upon completion of the method of this example, the treated AR glass articles (designated “Ex. 2”) exhibited a porosity-graded layer.
Referring now to
Referring now to
As is evident from
Embodiment 1. According to a first embodiment, a glass article is provided. The glass article comprises: a glass substrate comprising a thickness and a first primary surface; and a porosity-graded layer that extends from the first primary surface of the substrate to a first depth within the substrate. The first depth is from about 250 nm to about 3000 nm. The porosity-graded layer comprises a plurality of pores having an average pore size from about 5 nm to 100 nm. The article comprises a single-side average reflectance of less than 9% at an incident angle of 60 degrees across a spectrum from 350 nm to 2000 nm. The porosity-graded layer comprises a surface porosity at the first primary surface and a bulk porosity at the first depth, the surface porosity greater than the bulk porosity.
Embodiment 2. According to a second embodiment, the first embodiment is provided, wherein the article further comprises a single-side average reflectance of less than 5% at an incident angle of 45 degrees across a spectrum from 350 nm to 2000 nm.
Embodiment 3. According to a third embodiment, the first or second embodiment is provided, wherein the article further comprises a single-side average reflectance of less than 5% at an incident angle of 30 degrees across a spectrum from 350 nm to 2000 nm.
Embodiment 4. According to a fourth embodiment, any one of the first through third embodiments is provided, wherein the article further comprises a single-side average reflectance of less than 4% at an incident angle of 8 degrees across a spectrum from 350 nm to 2000 nm.
Embodiment 5. According to a fifth embodiment, any one of the first through fourth embodiments is provided, wherein the article further comprises a single-side average transmittance of greater than 90% at an incident angle of 30 degrees, 45 degrees or 60 degrees across a spectrum from 350 nm to 2000 nm.
Embodiment 6. According to a sixth embodiment, any one of the first through fifth embodiments is provided, wherein the article further comprises a single-side average reflectance of less than 1.5% at an incident angle of 8 degrees, 30 degrees or 60 degrees across a spectrum from 360 nm to 800 nm.
Embodiment 7. According to a seventh embodiment, any one of the first through sixth embodiments is provided, wherein the first primary surface comprises an average surface roughness (Ra) from about 1 nm to about 20 nm.
Embodiment 8. According to an eighth embodiment, any one of the first through seventh embodiments is provided, wherein the porosity-graded layer comprises a plurality of pores having an average pore size from about 10 nm to about 50 nm and a first depth from about 300 nm to about 1000 nm.
Embodiment 9. According to a ninth embodiment, a glass article is provided. The glass article comprises: a glass substrate comprising a thickness and a first primary surface; and a porosity-graded layer that extends from the first primary surface of the substrate to a first depth within the substrate. The first depth is from about 250 nm to about 3000 nm. The porosity-graded layer comprises a plurality of pores having an average pore size from about 5 nm to 100 nm. The porosity-graded layer comprises a surface porosity at the first primary surface and a bulk porosity at the first depth, the surface porosity greater than the bulk porosity. The porosity-graded layer comprises a refractive index as a function of depth within the substrate, nPGL(z), from the first primary surface to the first depth, given by
n
2
PGL(z)=n2substrate(1−fpore)+n2air*fpore,
where nsubstrate is the refractive index of the glass substrate, nair is the refractive index of air, and fpore is the volume fraction of the plurality of pores at the depth, z.
Embodiment 10. According to a tenth embodiment, the ninth embodiment is provided, wherein fpore is from 0.5% to about 20%.
Embodiment 11. According to an eleventh embodiment, the ninth or tenth embodiment is provided, wherein the porosity in the porosity-graded layer varies continuously from the first primary surface to the first depth.
Embodiment 12. According to a twelfth embodiment, any one of the ninth through eleventh embodiments is provided, wherein the article comprises a single-side average reflectance of less than 9% at an incident angle of 60 degrees across a spectrum from 350 nm to 2000 nm.
Embodiment 13. According to a thirteenth embodiment, any one of the ninth through twelfth embodiments is provided, wherein the article further comprises a single-side average reflectance of less than 5% at an incident angle of 45 degrees, 30 degrees or 8 degrees across a spectrum from 350 nm to 2000 nm.
Embodiment 14. According to a fourteenth embodiment, any one of the ninth through thirteenth embodiments is provided, wherein the article further comprises a single-side average transmittance of greater than 90% at an incident angle of 30 degrees, 45 degrees or 60 degrees across a spectrum from 350 nm to 2000 nm.
Embodiment 15. According to a fifteenth embodiment, any one of the ninth through fourteenth embodiments is provided, wherein the article further comprises a single-side average reflectance of less than 1.5% at an incident angle of 8 degrees, 30 degrees or 60 degrees across a spectrum from 360 nm to 800 nm.
Embodiment 16. According to a sixteenth embodiment, any one of the ninth through fifteenth embodiments is provided, wherein the first primary surface comprises an average surface roughness (Ra) from about 1 nm to about 20 nm.
Embodiment 17. According to a seventeenth embodiment, any one of the ninth through sixteenth embodiments is provided, wherein the porosity-graded layer comprises a plurality of pores having an average pore size from about 10 nm to about 50 nm and a first depth from about 300 nm to about 1000 nm.
Embodiment 18. According to an eighteenth embodiment, a method of making a glass article is provided. The method comprises: providing a silica-saturated solution; filtering the silica-saturated solution to remove insoluble silica particles from the silica-saturated solution and form a filtrated solution; and immersing a glass substrate comprising a thickness and a first primary surface with the filtrated solution, the immersing conducted to form a porosity-graded layer that extends from the first primary surface of the substrate to a first depth within the substrate. The silica-saturated solution comprises SiO2 gel, H2SiF6, H3BO3 or CaCl2), de-ionized H2O, and an optional amount of HCl. The first depth in the substrate is from about 250 nm to about 3000 nm. The porosity-graded layer comprises a plurality of pores having an average pore size from about 5 nm to 100 nm. The porosity-graded layer comprises a surface porosity at the first primary surface and a bulk porosity at the first depth, the surface porosity greater than the bulk porosity.
Embodiment 19. According to a nineteenth embodiment, the eighteenth embodiment is provided, wherein the immersing is conducted at 25° C. to 60° C. for about 2 minutes to about 60 minutes.
Embodiment 20. According to a twentieth embodiment, the eighteenth or nineteenth embodiment is provided, wherein the silica-saturated solution comprises from about 3% to 5% SiO2 gel, about 1.5 to 2.0 mol/L H2SiF6, about 20 to 40 mmol/L H3BO3 or CaCl2), 0 to 0.12 mol/L HCl, and a balance of de-ionized H2O (by weight).
Embodiment 21. According to a twenty-first embodiment, any one of the eighteenth through twentieth embodiments is provided, wherein the first primary surface comprises an average surface roughness (Ra) from about 1 nm to about 20 nm.
Embodiment 22. According to a twenty-second embodiment, any one of the eighteenth through twenty-first embodiments is provided, wherein the porosity-graded layer comprises a plurality of pores having an average pore size from about 10 nm to about 50 nm and a first depth from about 300 nm to about 1000 nm.
Embodiment 23. According to a twenty-third embodiment, any one of the eighteenth through twenty-second embodiments is provided, wherein the article comprises a single-side average reflectance of less than 9% at an incident angle of 60 degrees across a spectrum from 350 nm to 2000 nm.
Embodiment 24. According to a twenty-fourth embodiment, any one of the eighteenth through twenty-third embodiments is provided, wherein the porosity-graded layer comprises a refractive index as a function of depth within the substrate, nPGL(z), from the first primary surface to the first depth, given by
n
2
PGL(z)=n2substrate(1−fpore)+n2air*fpore,
where nsubstrate is the refractive index of the glass substrate, nair is the refractive index of air, and fpore is the volume fraction of the plurality of pores at the depth, z.
Embodiment 25. According to a twenty-fifth embodiment, any one of the eighteenth through twenty-fourth embodiments is provided, wherein fpore is from 0.5% to about 20%, and further wherein the porosity in the porosity-graded layer varies continuously from the first primary surface to the first depth.
Many variations and modifications may be made to the above-described embodiments of the disclosure without departing substantially from the spirit and various principles of the disclosure. All such modifications and variations are intended to be included herein within the scope of this disclosure and protected by the following claims.
This application claims the benefit of priority under 35 U.S.C. § 119 of U.S. Provisional Application Ser. No. 63/013,262 filed on Apr. 21, 2020, the content of which is relied up on and incorporated herein by reference in its entirety.
Filing Document | Filing Date | Country | Kind |
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PCT/US2021/026993 | 4/13/2021 | WO |
Number | Date | Country | |
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63013262 | Apr 2020 | US |