I am doing vaccum filtration to remove water after product washings, but the filter paper breaks into holes of Buckner funnel during filtration. I put a pair of Whatman paper on, making no difference. What should I do to avoid product loss?
You could also try using sintered glass funnels - they have a porous glass membrane (different grades available) rather than the large holes in a Buchner funnel, therefore don't require filter papers, and are much more robust and shouldn't collapse under vacuum.
You could also try using sintered glass funnels - they have a porous glass membrane (different grades available) rather than the large holes in a Buchner funnel, therefore don't require filter papers, and are much more robust and shouldn't collapse under vacuum.
You can try polymer membranes like Mixed Cellulose Esters (MCE) Membrane, PES (Polyethersulfone) Membranes, etc., Filter paper has lot of demerits like pore size variation due to hydrophilic nature of filter paper, physically not strong too.
Same problem occured for me when I was doing solids filtration.I think you can reduce the pressure. The whatmann filter paper can withstand only certain pressure. so by reducing the pressure rate we can solve this problem.
when we prepare nanoscale materials, we often use filter membrane. you can add some of solvents that can decrease the viscosity of solutions, but do not react with the target products. in addition, you can try centrifugation to remove large amount of solvent before filtration.
Friends, since m working in a rural university department having enormous prm of instruments, their maintenance & healthy atmosphere for research that contribute to unuse of centrifuge to small pressure pump, But m working honestly & attempting to manage sintered funnel, lets hope for the best. Thanks to all!
You can also try glass fiber filter paper. The pressure drop is likely to be less than for an equivalent paper filter.
Whenever filter paper breaks, I switch to using nylon or other polymeric filters. They are much stronger than filter papers. But take note of the polarity of the filter, as some are made for organics only or aqueous solutions only.
You should create a tee shape - this is commonly used in engineering. One portion to your filtration apparatus with a pressure/ vacuum gauage and the other to bleed to the atmosphere. Also wet your filtration apparatus with some of your filtration solvent to make sure paper sticks to the filtration funnel. Start with very low vacuum and slowly add your slurry to begin filtation. Once you have built a a few millimeters of cake, then slightly increase your vacuum.
Just try to filter according to Mr. Steven H chan. But try to filter it with small amount. You can try polymer based membranes such as MCE, Polyethylene sulphone membrane... Polymer based membranes can withstand vaccum pressure. Wattman paper can absorb the water. So it causes the variation in pore size and physical instability.
Tom's suggestion is great. I've been using a sintered glass filter base with a glass chimney for filtering. I needed the product to be collected ON a mixed-ester filter though so I could then use it in microscopy, so I place the filter directly on the sintered glass filter base. It works great. I still get the proper pore size of the mixed-ester filter but the sintered glass base provides complete support of the filter so it does not have break through or uneven filtering.
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