lotus effect with Colocasia fallax

From: Theodore Held <oppenhauser2001 at gmail.com> on 2011.01.12 at 18:04:17(21731) Geneviève, The lotus effect is quite common in my experience. It has been getting a lot of attention in the popular press lately and there are a number of academic studies of the phenomenon using nano materials. A Google search will turn up many hits. One of the best displays can be seen on the humble aroid Pistia. Leaves of Pistia will support quite a large water droplet with no wetting of the leaf surface that supports the hairs. Ted Held. +More Detroit 2011/1/11 Geneviève Ferry : > Dear aroiders , > > Today, three students came looking leaves Colocasia fallax to understand the > phenomenon of superhydrobicity (lotus effect). > Do you have information on this phenomenon? > (Experience, etc. ....) > > Thank you for your help. > > Best wishes , > > Geneviève Ferry > _______________________________________________ > Aroid-L mailing list > Aroid-L@www.gizmoworks.com > http://www.gizmoworks.com/mailman/listinfo/aroid-l > > _______________________________________________ Aroid-L mailing list Aroid-L@www.gizmoworks.com http://www.gizmoworks.com/mailman/listinfo/aroid-l

From: =?iso-8859-1?B?ZGF2aWQgYnL2ZGVyYmF1ZXI=?= <david_dav44 at hotmail.com> on 2011.01.13 at 12:53:25(21740) Hi Ted, Pistia is in fact a very beautiful example for a water-repellent surface. It has to be kept in mind - as you mention - that it generates this superhydrophobic effect with hairs (not with papillate cells like in Nelumbo or Colocasia) that are covered with wax. So, the term 'lotus-effect' describes the syndrom of superhydrophobicity (which means that the contact angle of a water droplet is at least 150°), but there are different structures within the Araceae and other plant families, that produce this effect. David Broederbauer HTML +More > Date: Wed, 12 Jan 2011 13:04:17 -0500 > From: oppenhauser2001@gmail.com > To: aroid-l@www.gizmoworks.com > Subject: Re: [Aroid-l] lotus effect with Colocasia fallax > > Geneviève, > > The lotus effect is quite common in my experience. It has been getting > a lot of attention in the popular press lately and there are a number > of academic studies of the phenomenon using nano materials. A Google > search will turn up many hits. > > One of the best displays can be seen on the humble aroid Pistia. > Leaves of Pistia will support quite a large water droplet with no > wetting of the leaf surface that supports the hairs. > > Ted Held. > Detroit > > 2011/1/11 Geneviève Ferry <jpcferry2@wanadoo.fr>: > > Dear aroiders , > > > > Today, three students came looking leaves Colocasia fallax to understand the > > phenomenon of superhydrobicity (lotus effect). > > Do you have information on this phenomenon? > > (Experience, etc. ....) > > > > Thank you for your help. > > > > Best wishes , > > > > Geneviève Ferry > > _______________________________________________ > > Aroid-L mailing list > > Aroid-L@www.gizmoworks.com > > http://www.gizmoworks.com/mailman/listinfo/aroid-l > > > > > _______________________________________________ > Aroid-L mailing list > Aroid-L@www.gizmoworks.com > http://www.gizmoworks.com/mailman/listinfo/aroid-l --_0b2d9375-fbdc-4bd4-9511-a284f79e2a09_-- --==============(42853695103802685=

From: Theodore Held <oppenhauser2001 at gmail.com> on 2011.01.16 at 21:09:12(21758) David, I have no idea whether or not individual Pistia hairs are coated with some form of wax or whether the wetting by water of an individual hair is simply poor enough to provide a bridge for the droplet surface over to the next surface hair, which bridging prevents wicking of the water down into the hairy structure. This would be a good research topic: Dry some Pistia leaves and see what is extracted (meaning dissolved by some liquid, ordinarily followed by gentle drying to investigate the residual - Steve Lucas was right to insist on technical terms being defined) by solvent (hexane or toluene would be good solvent candidates for wax) and if it is indeed a waxy substance. If no one has done this I'll do it myself and report back to this forum. Another thing that might be of interest to aroiders is that the net result of Pistia hydrophobicity (which merely means its reluctance to be wetted by water, typically observed as a tendency for water on a hydrophobic surface to "bead up" into discrete droplets) is the extreme buoyancy of the species. Try to submerge one of these plants and it's almost like you are trying to submerge an air bubble. It is curious to me how insubstantial a Pistia leaf is. It looks big, but when compacted and dried there is almost nothing left. Much of the apparent volume is simply air. Ted Held +More Detroit. On Thu, Jan 13, 2011 at 7:53 AM, david bröderbauer wrote: > Hi Ted, > > Pistia is in fact a very beautiful example for a water-repellent surface. It > has to be kept in mind - as you mention - that it generates this > superhydrophobic effect with hairs (not with papillate cells like in Nelu mbo > or Colocasia) that are covered with wax. So, the term 'lotus-effect' > describes the syndrom of superhydrophobicity (which means that the contact > angle of a water droplet is at least 150°), but there are different > structures within the Araceae and other plant families, that produce this > effect. > > David Broederbauer > >> Date: Wed, 12 Jan 2011 13:04:17 -0500 >> From: oppenhauser2001@gmail.com >> To: aroid-l@www.gizmoworks.com >> Subject: Re: [Aroid-l] lotus effect with Colocasia fallax >> >> Geneviève, >> >> The lotus effect is quite common in my experience. It has been getting >> a lot of attention in the popular press lately and there are a number >> of academic studies of the phenomenon using nano materials. A Google >> search will turn up many hits. >> >> One of the best displays can be seen on the humble aroid Pistia. >> Leaves of Pistia will support quite a large water droplet with no >> wetting of the leaf surface that supports the hairs. >> >> Ted Held. >> Detroit >> >> 2011/1/11 Geneviève Ferry : >> > Dear aroiders , >> > >> > Today, three students came looking leaves Colocasia fallax to understa nd >> > the >> > phenomenon of superhydrobicity (lotus effect). >> > Do you have information on this phenomenon? >> > (Experience, etc. ....) >> > >> > Thank you for your help. >> > >> > Best wishes , >> > >> > Geneviève Ferry >> > _______________________________________________ >> > Aroid-L mailing list >> > Aroid-L@www.gizmoworks.com >> > http://www.gizmoworks.com/mailman/listinfo/aroid-l >> > >> > >> _______________________________________________ >> Aroid-L mailing list >> Aroid-L@www.gizmoworks.com >> http://www.gizmoworks.com/mailman/listinfo/aroid-l > > _______________________________________________ > Aroid-L mailing list > Aroid-L@www.gizmoworks.com > http://www.gizmoworks.com/mailman/listinfo/aroid-l > > _______________________________________________ Aroid-L mailing list Aroid-L@www.gizmoworks.com http://www.gizmoworks.com/mailman/listinfo/aroid-l

From: =?iso-8859-1?Q?Genevi=E8ve_Ferry?= <jpcferry2 at wanadoo.fr> on 2011.01.17 at 18:20:00(21759) Dear Theodore, Many thanks for your help . The students have find many things with google . Best regards Geneviève +More -----Message d'origine----- From: Theodore Held Sent: Wednesday, January 12, 2011 7:04 PM To: Discussion of aroids Subject: Re: [Aroid-l] lotus effect with Colocasia fallax Geneviève, The lotus effect is quite common in my experience. It has been getting a lot of attention in the popular press lately and there are a number of academic studies of the phenomenon using nano materials. A Google search will turn up many hits. One of the best displays can be seen on the humble aroid Pistia. Leaves of Pistia will support quite a large water droplet with no wetting of the leaf surface that supports the hairs. Ted Held. Detroit 2011/1/11 Geneviève Ferry : > Dear aroiders , > > Today, three students came looking leaves Colocasia fallax to understand > the > phenomenon of superhydrobicity (lotus effect). > Do you have information on this phenomenon? > (Experience, etc. ....) > > Thank you for your help. > > Best wishes , > > Geneviève Ferry > _______________________________________________ > Aroid-L mailing list > Aroid-L@www.gizmoworks.com > http://www.gizmoworks.com/mailman/listinfo/aroid-l > > _______________________________________________ Aroid-L mailing list Aroid-L@www.gizmoworks.com http://www.gizmoworks.com/mailman/listinfo/aroid-l _______________________________________________ Aroid-L mailing list Aroid-L@www.gizmoworks.com http://www.gizmoworks.com/mailman/listinfo/aroid-l

From: =?iso-8859-1?Q?Genevi=E8ve_Ferry?= <jpcferry2 at wanadoo.fr> on 2011.01.18 at 05:35:59(21760) Dear David , Many thanks for your help . Geneviève HTML +More From: david bröderbauer Sent: Thursday, January 13, 2011 1:53 PM To: aroid-l@www.gizmoworks.com Subject: Re: [Aroid-l] lotus effect with Colocasia fallax Hi Ted, Pistia is in fact a very beautiful example for a water-repellent surface. It has to be kept in mind - as you mention - that it generates this superhydrophobic effect with hairs (not with papillate cells like in Nelumbo or Colocasia) that are covered with wax. So, the term 'lotus-effect' describes the syndrom of superhydrophobicity (which means that the contact angle of a water droplet is at least 150°), but there are different structures within the Araceae and other plant families, that produce this effect. David Broederbauer > Date: Wed, 12 Jan 2011 13:04:17 -0500 > From: oppenhauser2001@gmail.com > To: aroid-l@www.gizmoworks.com > Subject: Re: [Aroid-l] lotus effect with Colocasia fallax > > Geneviève, > > The lotus effect is quite common in my experience. It has been getting > a lot of attention in the popular press lately and there are a number > of academic studies of the phenomenon using nano materials. A Google > search will turn up many hits. > > One of the best displays can be seen on the humble aroid Pistia. > Leaves of Pistia will support quite a large water droplet with no > wetting of the leaf surface that supports the hairs. > > Ted Held. > Detroit > > 2011/1/11 Geneviève Ferry : > > Dear aroiders , > > > > Today, three students came looking leaves Colocasia fallax to understand the > > phenomenon of superhydrobicity (lotus effect). > > Do you have information on this phenomenon? > > (Experience, etc. .....) > > > > Thank you for your help. > > > > Best wishes , > > > > Geneviève Ferry > > _______________________________________________ > > Aroid-L mailing list > > Aroid-L@www.gizmoworks.com > > http://www.gizmoworks.com/mailman/listinfo/aroid-l > > > > > _______________________________________________ > Aroid-L mailing list > Aroid-L@www.gizmoworks.com > http://www.gizmoworks.com/mailman/listinfo/aroid-l _______________________________________________ Aroid-L mailing list Aroid-L@www.gizmoworks.com http://www.gizmoworks.com/mailman/listinfo/aroid-l ------=_NextPart_000_003B_01CBB6D9.F7E43E00-- --==============‰35918103884658447=

From: =?iso-8859-1?B?ZGF2aWQgYnL2ZGVyYmF1ZXI=?= <david_dav44 at hotmail.com> on 2011.01.18 at 08:17:38(21763) Hi Ted, As far as I know it was the Barthlott-group in Germany who studied the Pistia-leave under SEM. They showed that the hairs are coated with wax... David HTML +More > Date: Sun, 16 Jan 2011 16:09:12 -0500 > From: oppenhauser2001@gmail.com > To: aroid-l@www.gizmoworks.com > Subject: Re: [Aroid-l] lotus effect with Colocasia fallax > > David, > > I have no idea whether or not individual Pistia hairs are coated with > some form of wax or whether the wetting by water of an individual hair > is simply poor enough to provide a bridge for the droplet surface over > to the next surface hair, which bridging prevents wicking of the water > down into the hairy structure. > > This would be a good research topic: Dry some Pistia leaves and see > what is extracted (meaning dissolved by some liquid, ordinarily > followed by gentle drying to investigate the residual - Steve Lucas > was right to insist on technical terms being defined) by solvent > (hexane or toluene would be good solvent candidates for wax) and if it > is indeed a waxy substance. If no one has done this I'll do it myself > and report back to this forum. > > Another thing that might be of interest to aroiders is that the net > result of Pistia hydrophobicity (which merely means its reluctance to > be wetted by water, typically observed as a tendency for water on a > hydrophobic surface to "bead up" into discrete droplets) is the > extreme buoyancy of the species. Try to submerge one of these plants > and it's almost like you are trying to submerge an air bubble. It is > curious to me how insubstantial a Pistia leaf is. It looks big, but > when compacted and dried there is almost nothing left. Much of the > apparent volume is simply air. > > Ted Held > Detroit. > > On Thu, Jan 13, 2011 at 7:53 AM, david bröderbauer > <david_dav44@hotmail.com> wrote: > > Hi Ted, > > > > Pistia is in fact a very beautiful example for a water-repellent surface. It > > has to be kept in mind - as you mention - that it generates this > > superhydrophobic effect with hairs (not with papillate cells like in Nelumbo > > or Colocasia) that are covered with wax. So, the term 'lotus-effect' > > describes the syndrom of superhydrophobicity (which means that the contact > > angle of a water droplet is at least 150°), but there are different > > structures within the Araceae and other plant families, that produce this > > effect. > > > > David Broederbauer > > > >> Date: Wed, 12 Jan 2011 13:04:17 -0500 > >> From: oppenhauser2001@gmail.com > >> To: aroid-l@www.gizmoworks.com > >> Subject: Re: [Aroid-l] lotus effect with Colocasia fallax > >> > >> Geneviève, > >> > >> The lotus effect is quite common in my experience. It has been getting > >> a lot of attention in the popular press lately and there are a number > >> of academic studies of the phenomenon using nano materials. A Google > >> search will turn up many hits. > >> > >> One of the best displays can be seen on the humble aroid Pistia. > >> Leaves of Pistia will support quite a large water droplet with no > >> wetting of the leaf surface that supports the hairs. > >> > >> Ted Held. > >> Detroit > >> > >> 2011/1/11 Geneviève Ferry <jpcferry2@wanadoo.fr>: > >> > Dear aroiders , > >> > > >> > Today, three students came looking leaves Colocasia fallax to understand > >> > the > >> > phenomenon of superhydrobicity (lotus effect). > >> > Do you have information on this phenomenon? > >> > (Experience, etc. ....) > >> > > >> > Thank you for your help. > >> > > >> > Best wishes , > >> > > >> > Geneviève Ferry > >> > _______________________________________________ > >> > Aroid-L mailing list > >> > Aroid-L@www.gizmoworks.com > >> > http://www.gizmoworks.com/mailman/listinfo/aroid-l > >> > > >> > > >> _______________________________________________ > >> Aroid-L mailing list > >> Aroid-L@www.gizmoworks.com > >> http://www.gizmoworks.com/mailman/listinfo/aroid-l > > > > _______________________________________________ > > Aroid-L mailing list > > Aroid-L@www.gizmoworks.com > > http://www.gizmoworks.com/mailman/listinfo/aroid-l > > > > > _______________________________________________ > Aroid-L mailing list > Aroid-L@www.gizmoworks.com > http://www.gizmoworks.com/mailman/listinfo/aroid-l --_aa692191-b8cf-4caa-b1b8-768e807972f4_-- --=============="25912303437619595=

From: Theodore Held <oppenhauser2001 at gmail.com> on 2011.01.21 at 18:16:29(21787) David, Yes, I find what you say is correct. In fact, if anyone would like to read about the phenomenon in depth, including the Pistia references, just Google >Barthlott Pistia< and you'll get a Google book page that describes what the Barthlott people found as well as quite a bit more information about superhydrophobicity. Thanks for the reference. Ted Held +More Detroit. On Tue, Jan 18, 2011 at 3:17 AM, david bröderbauer wrote: > Hi Ted, > > As far as I know it was the Barthlott-group in Germany who studied the > Pistia-leave under SEM. They showed that the hairs are coated with wax... > > David > >> Date: Sun, 16 Jan 2011 16:09:12 -0500 >> From: oppenhauser2001@gmail.com >> To: aroid-l@www.gizmoworks.com >> Subject: Re: [Aroid-l] lotus effect with Colocasia fallax >> >> David, >> >> I have no idea whether or not individual Pistia hairs are coated with >> some form of wax or whether the wetting by water of an individual hair >> is simply poor enough to provide a bridge for the droplet surface over >> to the next surface hair, which bridging prevents wicking of the water >> down into the hairy structure. >> >> This would be a good research topic: Dry some Pistia leaves and see >> what is extracted (meaning dissolved by some liquid, ordinarily >> followed by gentle drying to investigate the residual - Steve Lucas >> was right to insist on technical terms being defined) by solvent >> (hexane or toluene would be good solvent candidates for wax) and if it >> is indeed a waxy substance. If no one has done this I'll do it myself >> and report back to this forum. >> >> Another thing that might be of interest to aroiders is that the net >> result of Pistia hydrophobicity (which merely means its reluctance to >> be wetted by water, typically observed as a tendency for water on a >> hydrophobic surface to "bead up" into discrete droplets) is the >> extreme buoyancy of the species. Try to submerge one of these plants >> and it's almost like you are trying to submerge an air bubble. It is >> curious to me how insubstantial a Pistia leaf is. It looks big, but >> when compacted and dried there is almost nothing left. Much of the >> apparent volume is simply air. >> >> Ted Held >> Detroit. >> >> On Thu, Jan 13, 2011 at 7:53 AM, david bröderbauer >> wrote: >> > Hi Ted, >> > >> > Pistia is in fact a very beautiful example for a water-repellent >> > surface. It >> > has to be kept in mind - as you mention - that it generates this >> > superhydrophobic effect with hairs (not with papillate cells like in >> > Nelumbo >> > or Colocasia) that are covered with wax. So, the term 'lotus-effect' >> > describes the syndrom of superhydrophobicity (which means that the >> > contact >> > angle of a water droplet is at least 150°), but there are different >> > structures within the Araceae and other plant families, that produce >> > this >> > effect. >> > >> > David Broederbauer >> > >> >> Date: Wed, 12 Jan 2011 13:04:17 -0500 >> >> From: oppenhauser2001@gmail.com >> >> To: aroid-l@www.gizmoworks.com >> >> Subject: Re: [Aroid-l] lotus effect with Colocasia fallax >> >> >> >> Geneviève, >> >> >> >> The lotus effect is quite common in my experience. It has been getting >> >> a lot of attention in the popular press lately and there are a number >> >> of academic studies of the phenomenon using nano materials. A Google >> >> search will turn up many hits. >> >> >> >> One of the best displays can be seen on the humble aroid Pistia. >> >> Leaves of Pistia will support quite a large water droplet with no >> >> wetting of the leaf surface that supports the hairs. >> >> >> >> Ted Held. >> >> Detroit >> >> >> >> 2011/1/11 Geneviève Ferry : >> >> > Dear aroiders , >> >> > >> >> > Today, three students came looking leaves Colocasia fallax to >> >> > understand >> >> > the >> >> > phenomenon of superhydrobicity (lotus effect). >> >> > Do you have information on this phenomenon? >> >> > (Experience, etc. ....) >> >> > >> >> > Thank you for your help. >> >> > >> >> > Best wishes , >> >> > >> >> > Geneviève Ferry >> >> > _______________________________________________ >> >> > Aroid-L mailing list >> >> > Aroid-L@www.gizmoworks.com >> >> > http://www.gizmoworks.com/mailman/listinfo/aroid-l >> >> > >> >> > >> >> _______________________________________________ >> >> Aroid-L mailing list >> >> Aroid-L@www.gizmoworks.com >> >> http://www.gizmoworks.com/mailman/listinfo/aroid-l >> > >> > _______________________________________________ >> > Aroid-L mailing list >> > Aroid-L@www.gizmoworks.com >> > http://www.gizmoworks.com/mailman/listinfo/aroid-l >> > >> > >> _______________________________________________ >> Aroid-L mailing list >> Aroid-L@www.gizmoworks.com >> http://www.gizmoworks.com/mailman/listinfo/aroid-l > > _______________________________________________ > Aroid-L mailing list > Aroid-L@www.gizmoworks.com > http://www.gizmoworks.com/mailman/listinfo/aroid-l > > _______________________________________________ Aroid-L mailing list Aroid-L@www.gizmoworks.com http://www.gizmoworks.com/mailman/listinfo/aroid-l

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