Porosity measurement using gallium-based invaders

Abstract

There is described a device (100) for determining information indicative of a porosity of a sample (111), the device comprising: i) a measurement chamber (110) configured to contain a sample (111) to be measured; ii) an invasive agent reservoir (120) configured to provide an invasive agent (125) to the measurement chamber (110); iii) a pressure device (130) configured to apply a pressure profile to the measurement chamber (110) such that the invasive agent (125) is pressed into at least a portion of the pore of the sample (111); and iv) a determination device (150) configured to determine information indicative of the porosity of the sample (111) based on the measured pressure, The invading agent (125) comprises gallium or a gallium alloy, and the apparatus (100) is configured to provide a reducing or inert condition relative to the invading agent (125).

Description

Technical Field

[0001] The invention relates to a device for determining information indicative of the porosity of a sample. Furthermore, the invention relates to a method for determining said information, for example using said device. Furthermore, the invention relates to the use of gallium or a gallium alloy as an intrusive agent in porosity measurements.

[0002] Therefore, the present invention may relate to the technical field of measurement technology, in particular porosity measurement. Background Art

[0003] Many materials include pores, and therefore include a measurable porosity. Porosity is a measure of the void (void) space in a material, and can be expressed, for example, as a volume fraction of the voids relative to the total volume of the material (e.g., expressed as a percentage). The porosity of a material can be important or even crucial information in many technical fields (e.g., pharmaceuticals, ceramics, metallurgy, materials science, mechanical engineering, geology, hydrology, etc.).

[0004] Various measurement techniques have been developed to measure the porosity of a sample, such as optical measurements (eg using a microscope), tomographic measurements (eg CT scanning), water evaporation measurements, gas expansion measurements, and mercury intrusion measurements.

[0005] Mercury intrusion can be considered the most common and economically important porosity measurement. The technique involves the intrusion of a non-wetting liquid (i.e., mercury) into a material within a porosimeter under high pressure. The pore size can be determined based on the external pressure applied to force the mercury into the pores against the reaction force of the liquid surface tension. Specifically, the pore size determination is performed using the Washburn equation. In addition, mercury intrusion (and extrusion) measurements can also further determine pore-related properties such as pore diameter, total pore volume, and surface area.

[0006] The main measured quantities are the volume of intruded mercury and the corresponding applied pressure. In addition, when the pressure is reversed, especially in high-pressure mercury porosimetry, the volume of squeezed mercury can be measured.

[0007] However, the use of mercury has several disadvantages. Mercury is toxic and harmful to the environment, so the used mercury must be recycled at a high cost. In addition, due to the toxicity of mercury vapor, the used mercury may not be suitable for recycling within the porosity measurement device. Summary of the invention

[0008] It may be desirable to perform porosity measurements in a cost-effective and environmental / health-friendly manner.

[0009] A device, method and purpose are provided.

[0010] According to a first aspect of the invention, a device for determining information indicative of the porosity of a sample, in particular a liquid (intrusion) porosimeter, is described, the device comprising:

[0011] i) a measurement chamber (in particular a penetrometer), which is configured to accommodate a sample to be measured;

[0012] ii) an invasive agent reservoir configured to (store the invasive agent and) provide the invasive agent to the measurement chamber (the measurement chamber and the invasive agent reservoir may be (directly) coupled);

[0013] iii) a pressure device (e.g. a piston providing pressure to a measurement chamber), the pressure device being configured to apply a pressure profile to the measurement chamber such that the intrusive agent is pressed into at least a portion of the pores of the sample;

[0014] (The device) in particular comprises a measuring device (such as a capacitive measuring device, an inductive measuring device, an optical measuring device, etc.) which is configured to measure a volume and / or a pressure associated with the provided pressure curve); and

[0015] iv) determining means (eg control means) configured to determine information indicative of the porosity of the sample based on the measured pressure curve (eg using the Washburn equation) and / or the (intruded / extruded) volume of the intruding agent.

[0016] The intrusive agent (being a gallium-based intrusive agent, i.e. the intrusive agent) comprises or consists of gallium or a gallium alloy. The apparatus is configured to provide reducing conditions (e.g. using a reducing agent such as an acid) and / or inert conditions (e.g. storing / transporting in an inert gas) with respect to the intrusive agent.

[0017] According to a second aspect of the invention, a method of determining information indicative of the porosity of a sample is described, the method comprising:

[0018] i) providing an intrusive agent to the sample to be measured,

[0019] wherein the intrusive agent comprises gallium or a gallium alloy;

[0020] ii) applying a pressure profile such that the intrusive agent is pressed into at least a portion of the pores of the sample;

[0021] (The method comprises in particular measuring the pressure in relation to the pressure curve and / or (the intrusion / extrusion volume of the intruding agent)

[0022] iii) determining information indicative of the porosity of the sample based on the pressure curve and / or the volume of the intrusive agent.

[0023] The method further comprises:

[0024] iv) providing reducing or inert conditions relative to the invading agent.

[0025] According to a third aspect of the invention, a use (method of use) of gallium or a gallium alloy as an intrusive agent in a porosimeter is described, wherein oxidation of the intrusive agent (particularly gallium oxide) is prevented by providing reducing conditions and / or inert conditions.

[0026] In the context of this document, the term "reducing conditions" may particularly refer to conditions in a specific region that favor chemical reduction reactions (as opposed to oxidation reactions). A reduction reaction may be a type of chemical reaction in which the oxidation state of an atom changes. In particular, a redox reaction may be characterized by an actual or formal transfer of electrons between chemical species, most commonly one substance (the reductant) undergoing oxidation (losing electrons) and another substance (the oxidant) undergoing reduction (gaining electrons). An example for reducing conditions herein may be providing a reducing agent at the surface of the intrusive agent (e.g. in an intrusive agent reservoir or in a measurement chamber). For example, the reducing agent may be configured as an acid, such as hydrochloric acid, which prevents the formation of gallium oxide and / or reacts with gallium oxide (Ga 2 O 3 ) chemically reacts to form the corresponding soluble gallium salt (e.g., gallium chloride (GaCl) in the case of HCl). 3 )). In this way, the reducing conditions can prevent the formation and / or presence of gallium oxide.

[0027] In the context of this document, the term "inert conditions" may particularly refer to conditions in a specific area that prevent chemical reactions, particularly oxidation reactions. An inert substance, particularly a fluid, may not react chemically under a given set of conditions. In an example, an inert gas, such as argon, is provided as an inert fluid to protect the intrusive agent, for example in an intrusive agent reservoir and / or in a measurement chamber, from oxidation. The inert fluid may be a cleaning gas and / or a working fluid, so that it can be used both to provide inert conditions for the intrusive agent and to accomplish the specific task of the porosity measurement.

[0028] In the context of this document, the term "pressure profile" may particularly refer to the variation over time of a predefined pressure applied to a measuring chamber. The pressure may force an intruding agent, which does not enter the pores under normal conditions due to its surface tension, into the pores. The required pressure may depend on the size of the pores. The pressure may be applied during the pressure profile in a continuous or stepwise pressure increase. In an example, the pressure profile is applied in two steps: a low-pressure measurement and a high-pressure measurement, in particular using different working fluids.

[0029] In the context of this document, the term "invasive agent" may particularly refer to a substance (particularly a fluid) suitable for being introduced into the pores of a sample under an applied pressure. Such an invasive agent may preferably be a non-wetting fluid which is substantially liquid under the measuring conditions. Furthermore, the invasive agent should be non-reactive with the sample. A common example of an invasive agent in porosimetry may be mercury. However, gallium-based invasive agents may be surprisingly effective alternatives.

[0030] According to an exemplary embodiment, the present invention may be based on the idea that when mercury as an intrusive agent is replaced by a gallium-based agent, and when the gallium-based intrusive agent is protected from oxidation (within the measuring device environment) by providing inert conditions and / or reducing conditions, porosity measurements may be performed in a cost-effective and environmental / health-friendly manner.

[0031] Gallium and gallium alloys comprise physical / chemical properties comparable to those of mercury and aluminum. Like mercury, gallium (alloys) can be liquid under the measurement conditions and thus a non-wetting liquid. Compared to mercury, gallium or gallium alloys can have the advantage of being neither toxic nor environmentally harmful. The recovery of gallium (alloys) in the context of porosity measurements can be carried out more efficiently, so that on the one hand costs can be saved, while on the other hand no waste disturbing the environment / health can be generated, which can be a large cost factor. Especially since current legislation requires the use of specially equipped hazardous rooms for handling mercury.

[0032] However, gallium (alloys) have a major disadvantage compared to mercury, which has prevented them from being considered as alternatives so far: Gallium can be easily oxidized to gallium oxide (especially Ga 2 O 3 ), the latter is not a non-wetting liquid (specifically, it is a dispersion of solid gallium oxide at the surface that makes the liquid wettable, whereby the solid is subsequently dissolved / reduced; due to cohesive / density surface tension it will remain on top), thereby hampering or even hindering the porosity measurement (e.g. by sticking to the measurement chamber, in particular the permeameter column).

[0033] The inventors have now surprisingly found that gallium (and gallium alloys) can still be used in an efficient manner in intrusion porosity measurements when specific measures are implemented to prevent oxidation of gallium in the measurement environment. The specific measures particularly include providing reducing or inert conditions. Specific embodiments of these conditions are described for the following exemplary embodiments.

[0034] Gallium (alloy) may further include a larger contact angle than mercury, allowing it to invade larger pores at the same pressure as mercury. In addition, gallium has a lower density than mercury (approximately half its density), so in addition to the contact angle, the hydrostatic pressure is significantly lower (and thus the maximum measurable pore is significantly larger). Therefore, even more accurate measurements may be achieved using gallium (alloy).

[0035] Furthermore, the described method can be directly implemented into existing porosity measurement systems, thus enabling simple application.

[0036] Exemplary Embodiments

[0037] According to an embodiment, the gallium alloy includes at least one metal selected from the group consisting of indium, tin, zinc, potassium, sodium, copper, silver, cesium, bismuth, antimony, lead, gold, thallium, palladium, platinum, selenium, lithium, and cadmium. In particular, the gallium alloy includes at least one of the group consisting of GaIn, GaInSn, GaZn, and GaInZn. This can provide the advantage that established and industrially relevant gallium alloys can be used directly as an intrusive agent. GaIn consists of, for example, 75.5% Ga and 24.5% In and is liquid at room temperature. GaInSn (trade name Galinstan ® ) is a eutectic alloy that is liquid at room temperature. GaInSn has low toxicity and low reactivity, so it may be well suited to replace mercury. In very specific examples, gallium alloys can include KNa, rubidium, or francium.

[0038] In the examples, any gallium alloy that is liquid under the measurement conditions (in particular room temperature) is suitable.

[0039] According to a further embodiment, the inert conditions include protection of the intrusive agent at least partially by an inert fluid, in particular an inert gas. The inert fluid can be applied to the intrusive agent in the device (e.g. located on top thereof). For example, an intrusive agent reservoir in which the intrusive agent is stored can be partially filled with an inert fluid. In a further example, the inert fluid can flow into the measuring chamber and protect the intrusive agent therein from oxidation. Furthermore, the intrusive agent can flow through a supply line of the device together with the inert fluid. In this way, effective protection against oxidation can be provided.

[0040] In an example, the inert fluid is selected from one of the group consisting of an inert gas (particularly argon), nitrogen, carbon monoxide (which may also be a reducing agent). In an example, the inert fluid may be used as a cleaning fluid for cleaning intrusive agents and / or (parts of) the device. In another example, the inert fluid may be used as a working fluid.

[0041] According to further embodiments, the reducing conditions include applying a reducing agent (to the intrusive agent). While the inert fluid (see above) provides inert conditions for the intrusive agent, the reducing agent (or reducing fluid) may provide reducing conditions that prevent oxidation and / or reduction of oxidized (intrusive agent) species (such as gallium oxide). In addition to or instead of the inert fluid, the reducing fluid may be provided to the intrusive agent in the device (e.g. in the intrusive agent reservoir, the measuring chamber and / or the supply line). In this way, effective protection against oxidation may be provided.

[0042] According to a further embodiment, the reducing agent comprises a gallium oxide dissolving fluid. This may provide the advantage that the gallium oxide species (in particular gallium oxide) are effectively reduced (removed), thereby allowing the intrusive agent to be recycled. According to a further embodiment, the reducing agent is applied as a fluid to the surface and / or phase boundaries of the intrusive agent. In this way, reducing conditions may be provided directly to the intrusive agent, in particular during storage of the intrusive agent (in the reservoir). Furthermore, in a determined chamber, the reducing agent may also cover the surface of the intrusive agent. In a specific embodiment (see Figure 6 ), in the measuring chamber, the intrusive agent is covered by the reducing agent, which is further covered by an inert (clean) fluid (gas).

[0043] According to further embodiments, the reducing agent comprises a chemically active substance, such as an acid or a base. In a specific example, at least one of hydrochloric acid, sulfuric acid, phosphoric acid, acetic acid and nitric acid is used. In another example, a base, such as sodium hydroxide (NaOH) or potassium hydroxide (KOH), is applied.

[0044] According to a further embodiment, the intrusive agent reservoir is configured to store the intrusive agent and provide the inert fluid and / or the reducing agent to the stored intrusive agent. Thus, the inert / reducing conditions can be directly and effectively provided to the stored intrusive agent.

[0045] According to another embodiment, the intrusive agent reservoir is configured to cover the surface of the stored intrusive agent, in particular to allow the inert fluid and / or reducing fluid to float on the intrusive agent. In this way, the surface of the intrusive agent can be effectively protected from oxygen and oxidizing substances.

[0046] According to a further embodiment, the determining means is further configured to determine information indicative of the porosity of the sample using the Washburn equation. This may provide the advantage that established evaluation schemes may be directly applied. While in other techniques, the evaluation of porosity may be performed using image analysis or magnetic resonance, the described method may apply a pressure curve evaluated using the established Washburn equation in the context of the measured pressure (and intrusive agent volume).

[0047] According to further embodiments, the device is further configured to provide a cleaning fluid (e.g., an inert fluid) and / or a reducing agent to at least a portion of the device and / or to the intrusive agent before and / or after the measurement (e.g., in an intrusive agent reservoir). While the cleaning fluid provides an inert condition, the reducing agent is configured to provide a reducing condition. The described device can be designed to protect the intrusive agent from oxidation at different locations and in different ways. Therefore, in practical embodiments, multiple combinations are possible. This again increases design flexibility.

[0048] According to a further embodiment, the device is configured to recover the spent intrusive agent by means of a reducing agent. In particular, during the measurement, the intrusive agent may become at least partially oxidized and may be recovered by the reducing agent.

[0049] According to a further embodiment, the measuring chamber is cleaned before the measurement. In an example, rinsing and brushing (with reducing fluid), rinsing with a cleaning solution (e.g. an alcohol such as isopropanol), drying with pressurized air may be applied. In a specific example, it may be advantageous to remove all high-pressure working fluid (oil) from the measuring chamber after the high-pressure measurement.

[0050] According to further embodiments, a cleaning step (eg with a cleaning fluid) may help to remove oxygen / oxidizing agents from the measurement chamber / device, in particular by further using a vacuum pump.

[0051] According to a further embodiment, the (recovered) intrusive agent and the recovering agent are separated from each other, for example using a filter.

[0052] According to another embodiment, the porosity measurement is performed under vacuum conditions (e.g. below 20 mBar, in particular below 10 -2 In a preferred example, the oxygen concentration during the measurement in the measurement chamber is below 100 ppm, in particular below 50 ppm, more particularly below 20 ppm, more particularly below 10 ppm.

[0053] According to a further embodiment, the device is further configured to operate in a low pressure mode. In the low pressure mode, a working fluid in the form of a gas may be applied as a pressure delivery medium to press the intrusive agent into the pores of the sample. Pressures in the range of several hundred bar may be used, for example about 600 bar.

[0054] According to further embodiments, a low pressure working fluid is applied to the intrusive agent as a pressure transmitting medium.

[0055] According to further embodiments, the low pressure working fluid comprises an inert gas or a reducing gas. This may provide the advantage of simultaneously providing inert / reducing conditions to the intrusive agent and fulfilling the function of the working fluid.

[0056] According to another embodiment, the low-pressure working fluid comprises a gas having an oxygen concentration of less than 100 ppm, in particular less than 50 ppm, more particularly less than 20 ppm, in particular less than 10 ppm. The same oxygen condition can also be applied to the entire measurement chamber. Thus, oxidation of the intrusive agent can be effectively prevented.

[0057] According to a further embodiment, a reducing agent is used to recover the intrusive agent after the low pressure measurement.

[0058] According to a further embodiment, the device is further configured to operate in a high pressure mode. In the high pressure mode, a working fluid in the form of a liquid may be applied as a pressure delivery medium to press the intrusive agent into the pores of the sample. Pressures in the range of several thousand bar may be used, for example about 6000 bar.

[0059] According to a further embodiment, a high-pressure working fluid is applied to the intrusive agent as a further pressure transmission medium.

[0060] According to further embodiments, the high pressure working fluid comprises an inert liquid or a reducing liquid. This may provide the advantage of simultaneously providing inert / reducing conditions to the intrusive agent and fulfilling the function of the working fluid.

[0061] In an example, the high pressure working fluid is silicone oil or mineral oil. Such oil may be substantially inert. However, the high pressure working fluid may include oxygen in the gallium oxide (alloy).

[0062] According to further embodiments, the reducing agent has low miscibility or is immiscible with respect to the pressurized working fluid, in particular the high-pressure working fluid.

[0063] According to a further embodiment, the reducing agent is located in the measuring chamber between the intrusive agent and the pressurized working fluid, in particular the low-pressure working fluid or the high-pressure working fluid (see Figure 6 ).

[0064] According to a further embodiment, at least one of the (inner) side walls of the measuring chamber comprises a coating configured to prevent adhesion of gallium oxide. This may provide the advantage of preventing gallium oxide from adhering to the side walls, thereby making it easier to remove the gallium oxide. In particular, the upper part of the penetrometer (rod) may be coated. In an example, this coating is particularly applied in the context of high-pressure measurements. Thus, the coating may replace the reducing agent (measurement without reducing agent) between the intrusive agent and the high-pressure working fluid (e.g. Figure 6 In a specific example, the coating can include indium (III) oxide.

[0065] According to a further embodiment, the reducing agent has low miscibility or immiscibility with respect to the pressure working fluid, in particular the high-pressure working fluid, and thus serves as protection against oxidation during low-pressure / high-pressure measurements. In particular, an aqueous acid / base is applied as reducing agent together with the lipophilic pressure medium (working fluid).

[0066] According to another embodiment, a reducing agent is used to recover the intrusive agent after high pressure measurement. Since the high pressure working fluid (for example, in the case of oil) may form a film on the intrusive agent, a film remover (for example, an alcohol such as isopropyl alcohol) may be used to remove the film before recovery.

[0067] In a specific example, a reducing agent / fluid (or inert fluid) is provided between the intruding agent and the (high pressure) working fluid (see e.g. Figure 6 ). This effectively prevents the formation of an unwanted oxygen layer.

[0068] According to further embodiments, the reducing conditions include applying an exchange process to remove oxidants and / or oxidized intrusive agents (particularly gallium oxide) and / or reducing agents and / or reduced gallium species from the intrusive agent. This may provide the advantage that undesirable species may be effectively removed. Under certain conditions, the reducing agent may be unsuitable (e.g. due to corrosion) and should then be removed. Reduced gallium species (e.g. gallium chloride) may be undesirable and may then be removed.

[0069] According to further embodiments, the exchange process comprises at least one of membrane, ion exchange, osmosis, density separation, filtration. Thus, the establishment means can be directly applied to achieve effective separation.

[0070] According to a further embodiment, the device further comprises an oxygen sensor configured to monitor the oxygen concentration in at least a portion of the device, in particular the oxygen concentration in the inert fluid. Since oxygen provides oxidizing conditions, which can be a major problem when using gallium-based intrusive agents, the oxygen sensor can be used as a general and advantageous monitoring tool and / or as an alarm function to keep the oxygen level as low as possible.

[0071] According to a further embodiment, the device is also configured to recycle the intrusive agent after the measurement and to apply the recycled intrusive agent in further measurements. This can provide the advantage that the (recycled) intrusive agent can be used multiple times, thereby saving the (substantial) cost of purchasing new intrusive agents and recycling the used intrusive agents. As described above, the used intrusive agent can be treated with a reducing agent to remove oxidized substances. In addition, separation techniques such as filters can be applied to remove undesirable substances and / or reaction products. Recycling can be directly implemented into the described device. In another example, recycling can be carried out in a separate device.

[0072] According to a further embodiment, the device is configured as an intrusive porosimeter. Thus, the described method can be directly implemented into existing (see e.g. Figure 1 ) porosimeter design. The measurement chamber can be configured as an established penetrometer.

[0073] According to a further embodiment, the pressure device is coupled to a pressure unit, in particular a pressure unit around the measuring chamber. Likewise, the described method can be directly implemented into existing (see for example Figure 4 and Figure 5 ) and tested porosimeter designs. BRIEF DESCRIPTION OF THE DRAWINGS

[0074] The aspects defined above and further aspects of the present invention are apparent from the examples of embodiment to be described hereinafter and are explained with reference to these examples of embodiment.

[0075] Figure 1 The figure shows an apparatus for porosity measurement according to an exemplary embodiment of the present invention.

[0076] Figure 2 The figure shows an invasive agent reservoir according to an exemplary embodiment of the present invention.

[0077] Figure 3 The figure shows an invasive agent reservoir according to a further exemplary embodiment of the present invention.

[0078] Figure 4 The figure shows a device for porosity measurement in low pressure mode according to an exemplary embodiment of the present invention.

[0079] Figure 5 The figure shows a device for porosity measurement in high pressure mode according to an exemplary embodiment of the present invention.

[0080] Figure 6 The figure shows a measurement chamber according to an exemplary embodiment of the invention. DETAILED DESCRIPTION

[0081] The illustrations in the drawings are schematic. In different drawings, similar or identical elements are provided with the same reference signs.

[0082] Figure 1The figure shows an apparatus 100 for porosity measurement according to an exemplary embodiment of the present invention. The apparatus 100 is configured to determine information indicating the porosity of a sample 111 and includes a measurement chamber 110 accommodating the sample 111. The measurement chamber 110 is configured as a penetrometer and includes a cavity in which the sample 111 is placed and a column extending away from the sample 111 in a vertical direction. The sample 111 is introduced from below and then held in place by a closure 112. The penetrometer 113 is further arranged in a pressure unit 115. A vacuum pump 135 establishes a vacuum in the measurement chamber 110.

[0083] The device 100 further comprises an intrusive agent reservoir 120 storing an intrusive agent 125 which is gallium or a gallium alloy. In the case of gallium alone, an additional heating step may be required (melting point 29.8° C.). The intrusive agent reservoir 120 is connected to the measurement chamber 110 (in particular the column) so that the intrusive agent 125 can flow directly from the reservoir 120 through a valve into the measurement chamber 110 (the column). In the example shown, the intrusive agent 125 has filled the measurement chamber 110 up to the meniscus 114 in the column. Furthermore, the intrusive agent reservoir 120 is connected to a supply of the intrusive agent 125. The supply may be fresh intrusive agent 125, recycled intrusive agent 125 (from the same or different measurement) or a mixture of both.

[0084] An inert fluid 126 (eg, a cleaning and / or protection fluid) may be supplied to the aggressive agent reservoir 120 to provide (chemically) inert conditions within the aggressive agent reservoir 120. Specifically, the inert fluid 126 prevents the aggressive agent 120 from oxidizing within the aggressive agent reservoir 120.

[0085] Additionally or alternatively, a reducing fluid 180 may be supplied to the intrusive agent reservoir 120 to provide (chemical) reducing conditions within the intrusive agent reservoir 120. Specifically, the reducing fluid 180 prevents the intrusive agent 125 from oxidizing within the intrusive agent reservoir 120 and / or reacting with oxidizing species.

[0086] The apparatus 100 further comprises a pressure device 130 configured to apply a pressure profile to the measurement chamber 110 such that the intrusive agent 125 is pressed into at least a portion of the pores of the sample 111. In this example, the pressure device is configured as a piston connected to a pressure cell. A measuring device 140 of the apparatus 100 is coupled to the pressure device 130 and is configured to measure the pressure associated with the provided pressure profile (relative to the corresponding intrusive agent volume). In this example, the measuring device 140 comprises a capacitive measuring member 141 connected to the bottom of the measurement chamber. The drop in the intrusive agent level in the capillary is recorded capacitively, and therefore also the exact amount of the intrusive gallium (alloy) volume relative to the corresponding applied pressure.

[0087] Furthermore, the apparatus 100 comprises a determination device 150 coupled to the measurement device 140, said determination device being configured to determine information indicative of the porosity of the sample 111 based on the measured pressure using the Washburn equation.

[0088] An inert fluid 126, a reducing agent 180, a low-pressure working fluid 127, and / or a high-pressure working fluid 128 may be introduced into the measurement chamber 110 via an additional supply line 129. Each of these fluids may be configured to provide inert or reducing conditions for the intrusive agent 125 in the measurement chamber 110. The working fluid and the cleaning fluid may be the same here, but both provide inert / reducing conditions.

[0089] Thus, the device 100 is configured to provide reducing or inert conditions with respect to the invading agent 125 by providing the corresponding fluid 126, 127, 128, 180 in the measuring chamber 110 and / or in the invading fluid reservoir 120, as described above.

[0090] Figure 2 FIG. 1 shows an invasive agent reservoir 120 (particularly from a device for Figure 1 The device 100 described herein). In this example, the intrusive agent reservoir 120 includes two parts, the upper part is a cleaning unit, in which the intrusive agent 125 is mixed with an inert cleaning fluid 126, and the cleaning unit can be supported directly on top of the intrusive agent 125. The cleaned intrusive agent 125 then flows through a valve to the second part below. The second part includes a membrane 185 between immiscible phases, which separates the second part into an intrusive agent 125 compartment and a reducing agent 180 compartment. Each of the intrusive agent 125 and the reducing agent 180 includes a separate inlet and outlet. In this way, the intrusive agent 125 can flow from the clean part to the intrusive agent 125 compartment, and then further flow out of the reservoir 120 to the measuring unit 110. The reducing agent 180 can flow into the reducing agent compartment, and then further flow out of the reservoir 120. At the membrane, the reducing agent 180 provides a reducing condition so that oxidation of the intrusive agent 180 is prevented, in particular, the oxidized species are reduced.

[0091] Figure 3 FIG. 1 shows an invasive agent reservoir 120 (particularly from a device for Figure 1100 described). The reservoir 120 comprises side walls 121 defining a volume therebetween and a cover 122 as a top side wall (inert material). At the bottom of the reservoir 120, there is an intrusive agent 125 as a gallium-based liquid. The intrusive agent 125 can be supplied directly to the measuring chamber 110 via a valve (not shown here). Above the intrusive agent 125, there is a reducing agent / fluid 180, such as an acid. Furthermore, above the reducing agent 180, there is an inert fluid 126 which can be provided via an inert fluid 126 supply line. In the present case, the inert fluid 126 is an inert gas which is present in the headspace of the reservoir 120 and forms an inert gas blanket for the reducing agent 180 and the intrusive agent 125. In this configuration, the intrusive agent reservoir 120 can be a reservoir and a cleaning unit at the same time.

[0092] Figure 4 The figure shows a device 100 for porosity measurement in low pressure mode according to an exemplary embodiment of the present invention. The device 100 is very similar to the one for Figure 1 The pressure device 130 is configured to press the low-pressure working fluid 127 into the measurement chamber 110 so that the intrusive agent 125 in the measurement chamber 110 is forced into the pores of the sample 111. In an example, a pressure in the range of several hundred bar (e.g., 600 bar) is applied. The low-pressure working fluid is preferably an inert gas such as argon or nitrogen with a very low oxygen content (e.g., below 50 ppm).

[0093] Figure 5 The figure shows an apparatus 100 for porosity measurement in high pressure mode according to an exemplary embodiment of the present invention. The apparatus 100 is very similar to the apparatus for Figure 1 The pressure device 130 is configured to press the high-pressure working fluid 128 into the measurement chamber 110 so that the intrusive agent 125 in the measurement chamber 110 is forced into the pores of the sample 111. In an example, a pressure in the range of several thousand bar (e.g., 6000 bar) is applied. The high-pressure working fluid 128 is preferably a liquid such as silicone oil.

[0094] Figure 6 The figure shows a measurement chamber 110 (column) according to an exemplary embodiment of the present invention. The measurement chamber 110 is configured as a penetrometer 113 and Figure 6 Only the bars are shown (compared to Figure 1). A penetrant 125 is present in the column and can be directed into the sample 111 below (not shown in this figure). The penetrant 125 fills the column up to the meniscus 114. The penetrant 125 is covered by a reducing agent 180 (hydrochloric acid in this example). The reducing agent 180 is further covered by a high pressure working fluid 128 (oil in this example). In this way, the penetrant 125 can be effectively protected from oxidation during the measurement phase.

[0095] Reference numerals

[0096] 100 Equipment, porosity meter

[0097] 110 Measuring chamber, penetrometer

[0098] 111 Samples with pores

[0099] 112 Closure

[0100] 113 Penetrometer

[0101] 114 Meniscus

[0102] 115 Pressure unit

[0103] 120 Invasive Agent Reservoir

[0104] 121 Sidewall

[0105] 122 Cover

[0106] 125 Intrusion agent, gallium (alloy)

[0107] 126 Inert fluid, cleaning fluid

[0108] 127 Low pressure working fluid

[0109] 128 High-pressure working fluid

[0110] 129 Additional supply lines

[0111] 130 Pressure device

[0112] 135 Vacuum Pump

[0113] 140 Measuring device

[0114] 141 Capacitance Measurement

[0115] 150 Determine the device

[0116] 180 Reducing agent

[0117] 185 membrane.

Claims

1. A device (100) for determining information indicative of the porosity of a sample (111), in particular a liquid intrusion porosimetry device, the device comprising: a measurement chamber (110) configured to accommodate a sample (111) to be measured; an invasive agent reservoir (120) configured to provide an invasive agent (125) to the measurement chamber (110); a pressure device (130) configured to apply a pressure profile to the measurement chamber (110) such that the intrusive agent (125) is pressed into at least a portion of the pores of the sample (111); as well as a determination device (150) configured to determine information indicative of the porosity of the sample (111) based on the applied pressure curve and / or the volume of the intrusive agent (125); wherein the intrusive agent (125) comprises gallium or a gallium alloy; and The device (100) is configured to provide reducing conditions and / or inert conditions relative to the intrusive agent (125).

2. The device (100) according to claim 1, wherein the gallium alloy comprises at least one metal selected from the group consisting of indium, tin, zinc, potassium, sodium, copper, silver, cesium, bismuth, antimony, lead, gold, thallium, palladium, platinum, selenium, lithium, and cadmium, In particular, the gallium alloy comprises at least one of the group consisting of GaIn, GaInSn, GaZn, and GaInZn.

3. The device (100) according to claim 1 or 2, The inert conditions include at least partial protection of the intrusive agent (125) by an inert fluid (126), in particular an inert gas.

4. The device (100) according to any one of the preceding claims, wherein the reducing conditions include applying a reducing agent (180), in particular an oxide dissolving fluid, to the intruding agent (120), In particular, wherein the reducing agent (180) is applied as a fluid to the surface and / or phase boundary of the invading agent (125), More particularly wherein the reducing agent (180) comprises an acid or a base.

5. The device (100) according to claim 3 or 4, wherein the invasive agent reservoir (120) is configured to store the invasive agent (125) and provide the inert fluid (126) and / or the reducing agent (180) to the stored invasive agent (125), In particular, it is configured to cover the surface of the stored intrusive agent (125), more particularly, to make the inert fluid (126) and / or the reducing fluid (180) float on the intrusive agent (125).

6. The device (100) according to any one of the preceding claims, The determining device (150) is further configured to determine information indicative of the porosity of the sample (111) using the Washburn equation.

7. The device (100) according to any one of the preceding claims, is also configured to supply a cleaning fluid (126, 180), in particular the inert fluid (126) and / or the reducing agent (180), to at least a portion of the device (100) and / or to the intrusive agent (125) before and / or after the measurement, In particular, within the invasive agent reservoir (120).

8. The device (100) according to any one of the preceding claims, Also configured to operate in low voltage mode, wherein a low-pressure working fluid (127) is applied to the intrusive agent (125) as a pressure delivery medium, In particular, wherein the low-pressure working fluid (127) comprises an inert gas (126) or a reducing gas (180), More particularly, it is a gas (126, 180) having an oxygen concentration of less than 100 ppm, particularly less than 50 ppm, more particularly less than 20 ppm, more particularly less than 10 ppm.

9. The device (100) according to any one of the preceding claims, Also configured to operate in high voltage mode, wherein a high pressure working fluid (128) is applied to the intrusive agent (125) as an additional pressure delivery medium, In particular, the high pressure working fluid (128) comprises an inert liquid, more particularly silicone oil or mineral oil.

10. The device (100) according to claim 8 or 9, wherein the reducing agent (180) has low miscibility or immiscibility with respect to the pressurized working fluid (127, 128), in particular the high-pressure working fluid (128); and / or The reducing agent (180) is located between the intrusive agent (120) and the pressure working fluid (127, 128), in particular in the measuring chamber (110), and in particular, the pressure working fluid is the low-pressure working fluid (127) or the high-pressure working fluid (128).

11. The device (100) according to any one of the preceding claims, further comprising: An oxygen sensor is configured to monitor the oxygen concentration in at least a portion of the apparatus (100), in particular the oxygen concentration of the inert fluid (126).

12. The device (100) according to any one of the preceding claims, The method is further configured to recirculate the intrusive agent (125) after the measurement and to apply the recirculated intrusive agent (125) in further measurements.

13. The device (100) according to any of the preceding claims, further comprising at least one of the following features: wherein the apparatus (100) is configured as an intrusion porosimeter; wherein the measuring chamber (110) comprises a penetrometer (113); wherein at least one measuring chamber (110) sidewall comprises a coating configured to prevent adhesion of metal oxides, in particular gallium oxide; wherein the reducing conditions comprise applying an exchange process to remove the oxidant and / or oxidized intrusive agent, in particular gallium oxide, from the intrusive agent, In particular, the exchange process comprises at least one of membrane (185), ion exchange, osmosis, density separation, filtration.

14. A method of determining information indicative of porosity of a sample (111), the method comprising: Providing an intrusive agent (125) to a sample (111) to be measured, wherein the intrusive agent (125) comprises gallium or a gallium alloy; applying a pressure profile such that the intrusive agent (125) is pressed into at least a portion of the pores of the sample (111); determining information indicative of the porosity of the sample (111) based on the applied pressure profile and / or the volume of the intrusive agent (125); and The method further comprises: Reducing conditions and / or inert conditions relative to the invading agent (125) are provided.

15. Use of gallium or a gallium alloy as an intrusive agent (125) in a porosimeter (100), wherein oxidation of the intrusive agent (125) is prevented by providing reducing conditions and / or inert conditions.

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