Standard Operating Procedure Porosity Analyzer - The Micromeritics Tri-Star II (surface area) with Micrometrics VacPrep 061 (Sample Degas System) The Micromeritics Tri-Star II Surface Area and Porosity Analyzer allows for the analysis of specific surface area and pore size distribution of powders or other nano-structures. It is specially designed for those porous materials with mesopore size between 2 and 50 nm. The Micrometrics VacPrep 061 Sample Degas System works together with the Surface Area and Porosity Analyzer to prepare samples. It removes contaminants such as water vapor and adsorbed gases from samples to avoid interference with surface area measurements. It works in a vacuum mode which prepares samples by heating and evacuation. 1.0 Operation Procedure The VacPrep 061 degas system may involve high temperature degas process. Be cautious to operate the degas system at high temperature. Both the degas system and the instrument incorporate a vacuum, which may be a potential safety hazard and should be treated with caution. The analysis is conducted in liquid nitrogen environment. Be cautious to the cryogenic safety when the system is running. Always wear cryogenic safe gloves and safety goggles when you deal with liquid nitrogen. The system uses highly pressurized helium gas to measure free space in the sample. Be cautious to the highly pressurized gas when you replace a gas bottle. Be cautious to the chemical safety when you load and/or unload the sample into/out of the tube. Always handle your sample in a fume hood. 1.1 Samples Preparation a. Clean and dry the sample tube set (sample tube, filler rod and seal frit) b. Weigh the mass of empty sample tube set c. Remove the filler rod and seal frit, carefully load your sample into the tube, and then replace the filler rod and seal frit d. Install the sample tube set on the VacPrep 061 degas system NOTE: Do not lose the connector nut, ferrule and O-ring in the degas system e. Turn on the degas system and plug in the power cord of the degasser pump f. Set your desired degas temperature g. Switch the relevant control knob from Off to Vac h. Wait for the vacuum pressure to be below 0.2 mtorr i. Switch the control knob from Vac to Gas Page1
j. Wait for the 5-10 seconds k. Switch the control knob from Gas to Vac l. Repeat Step 8 through Step 11 for two more runs m. Keep the control knob at Vac position n. Wait for several hours to degas your sample. The ultimate vacuum pressure should be within the range of 0.05-0.1 mtorr. o. Upon completion the degas process, switch the control knob from Vac to Off p. Turn off the degas system and unplug the power cord of the degasser pump q. Uninstall the sample tube set from the degas system r. Weigh the mass of sample tube set along with the sample 1.2 Create a Sample Information File a. Launch the control software TriStar II 3020 on the desktop b. To create a new Sample Information file (.smp), click File Open Sample Information c. In the dialog of Open Sample Information File, select the directory to save the new.smp file, and give the File name. Then, click Yes to confirm. Page2
d. There are 6 tabs: Sample Information, Sample Tube, Degas Conditions, Analysis Conditions, Adsorptive Properties and Report Options. Please define the settings in each tab one by one. e. In Sample Information tab: Sample: enter your sample name Operator: enter the name of the operator who will perform the measurement Submitter: enter the name of the person (or department) submitting the sample for test Mass: select Calculate, enter the measured values for Empty tube and Sample + tube. The difference is the net mass of your sample. Type of Data: select Automatically collected Comments: enter comments about the sample or its analysis conditions. Comments entered here are printed in the header of the reports. Add Log Entry: enter information pertinent to the sample file. Any information you enter here is printed as part of the sample log report. Click Save, then click the next tab Page3
f. In Sample Tube tab: Select Use isothermal jacket and Use filler rod Vacuum seal type: select Seal Frit Click Save, then click the next tab g. In Degas Conditions tab: Enter the values of Temperature, Temperature Ramp Rate and Time (when you perform the degas process with VacPrep 061 Sample Degas System) Page4
Click Save, then click the next tab h. In Analysis Conditions tab: Click Replace to select an existing analysis conditions template file (.anc). If you wish to create a new.anc file, simply enter the name in Description. Select Target Pressures, then click Pressures Edit the existing pressure table or clear the table and enter a new pressure table: Page5
A pressure table is a table of relative pressure points at which the isotherms data are to be collected. The relative pressures may span the entire isotherm range from 0.00000001 to 0.995 P/Po. There must be one adsorption branch followed optionally by one desorption branch. You should also check each data point for calculation assignments. Click Preparation to open Analysis Preparation dialog. Change Evacuation time to be 0.30 hours. If you wish to perform leak test, select Leak test (optional). Click OK. Page6
Click Free Space to open Free Space dialog. Select Measure. Check Lower dewar for evacuation and change Evacuation time to be 0.30 h. If you wish to perform outgas test, select Outgas test (optional). Click OK. Click Save, then click the next tab i. In Adsorptive Properties tab: Click Replace to select the existing nitrogen.adp file. Then, click OK. The Adsorptive field will display Nitrogen @ 77.35 K. Page7
Click Save, then click the next tab j. In Report Options tab: Click Replace to select an existing report options template file (.rpo). If you wish to create a new.rpo file, simply enter the name in Description. In the list of Selected Reports, check all the types of reports that you want to generate Page8
Click Edit to display an associate dialog for the selected report, if you wish to edit the report options. Then, click OK. Click Save, then click Close. 1.3 Sample Loading a. Remove the flat bottom protective tube from the analysis port b. Slide an isothermal jacket down over the stem of the sample tube until it touches the bulb of the sample tube c. Place the connector nut, ferrule and O-ring onto the sample tube stem d. Attach the sample tube to the analysis port. Make sure it is fully in the port; secure in place by screwing the connector nut onto the analysis port. Hand-tighten the connector nut. 1.4 Start the Measurement a. Plug in the power cord of the instrument pump b. In the control software, click Unit 1 Sample Analysis, the Analysis dialog is displayed Page9
c. Click Browse to choose a sample information file (.smp) to be used for each port you plan to use d. Verify the sample identification and the sample mass e. Select Report after analysis to have reports generated automatically when the analysis completes. By default, the report will be generated on screen. f. Click Export after analysis to have isotherm data exported automatically when the analysis completes. Be sure to designate the destination if you choose this option. g. Click Start to start the analysis. An analyzing view of the window is displayed so that you can view data as it is collected. NOTE: The tube should be installed onto the analysis port very straightly. Any tilting of the tube will cause air leak and inaccurate results. Do not bend the Po tube at the center. h. Fill the analysis dewar with LN2. Insert the dipstick into the dewar and check the level of LN2. Condensation of LN2 should not exceed the Level Indicator Mark (a hole on the dipstick). i. Place the analysis dewar onto the elevator j. Close the sample compartment door NOTE: Wear cryogenic safe gloves and safety goggles when you deal with LN2 Page10
1.5 After the Measurement a. After the analysis is finished, a report will be generated on screen. Save the report as.rep file or print the report as.pdf file. b. Close the control software c. Unplug the power cord of the instrument pump d. Recycle the LN2 from the analysis dewar (if any) e. Uninstall the sample tube set from the analysis port f. Replace the flat bottom protective tube on the analysis port g. Close the sample compartment door h. Dispose of your sample appropriately and thoroughly clean the sample tube set 2.0 Specifications/Features Micromeritics Tri-Star II Surface Area and Porosity Analyzer Three independent analysis ports operate simultaneously Minimum surface area to measure: 0.01 m 2 /g (with Kr) Adsorbate gas for specific surface area test: N2 (available) or Kr (upon request) LN2 test temperature Data points: 5-1000 A dedicated Po port allows for measurement of saturation pressure on a continuous basis Saturation pressure entered manually, measured continuously, or collected over the sample Micromeritics VacPrep 061 Sample Degas System o Six sets of sample kits: sample tubes (1/2 O. D.), filler rods, seal frits, tube holders, isothermal jackets o Heating block temperature: up to 400 ºC, with accuracy ±5 ºC 3.0 User Requirements The Micromeritics Tri-Star II 3020 Surface Area and Porosity Analyzer must be used by authorized personnel only. All authorized users are expected to read and understand this SOP and follow the operation instructions carefully. No unauthorized user may operate this Surface Area and Porosity Analyzer unless accompanied by an authorized user. All visitors must be Page11
briefed on proper safety protocol and must wear appropriate personal protective equipment. To become an authorized user, one must: 1. Complete Environment, Health & Safety (EH&S) training 2. Complete initial orientation and training for the Materials Characterization Laboratory 3. Receive training on this piece of equipment from lab personnel 4. Schedule equipment time using the calendar 5. Read and fully understand this SOP 4.0 General Safety 4.1 Required Personal Protective Equipment Users must wear lab coats, safety glasses, and gloves. Shorts, open-toed shoes, high heels, and skirts, are forbidden. 4.2 Emergency Procedures and Contacts For non-life threatening emergencies: notify the MCL facility manager and your PI immediately. Facility manager: Zongmin (Shirley) Bei, Ph.D. Office: 109B Furnas Hall, Tel: (716) 645-5165, Cell: (585) 354-5623 Email: zongminb@buffalo.edu or for police / ambulance, call 645-2222 In case of fire or other life threatening emergency: Exit the laboratory through an emergency exit door. Pull one of the fire alarms located in the main hallway. Dial campus police / ambulance at 645-2222. 4.3 University after hours laboratory use policy No working alone, use the buddy system! # Revised by Date Modification 1 Zongmin (Shirley) Bei 05/02/2016 Document initial release 2 3 4 5 Page12