Dear Sanghyun,

We did sillver nanowires mixing with SU8 which worked very well. In principle silver nanoparticles should work too. If you consider transparent conducting films, definitely you should use silver nanowires.

Hope it helps

Xuhua

Thanks madam, can I give you one more question?

I bought Ag Nanoparticle (

You can use IPA and aceton using centrifuges to wash away PVP. Once you did it, you need to get the nanoparticles immediately to disperse in a solvent. Not allow to dry out. Otherwise it clumps together. It is difficult to disperse into a solvent.

Xuhua Wang

After I discussed this issue with my team, we decided to follow your suggestion. Therefore, Can I give you two more miscellaneous question, madam?

1. Did your team purchase silver nanowire from other company or synthesize it by yourself? As far as I found, most of papers dealing with AgNW-polymer nanocomposite synthesized it by themselves.

2. You said centrifuges may help to remove PVP from AgNP. If I use ethanol to wash away PVP, then the process would be as follow???

AgNP(PVP coated) + ethanol -> centrifuge -> remove suspension(PVP) -> move precipitation(AgNP) directly into solvent where I'm going to mix with polymer resin

It would be also thankful if you forward me the your published paper dealing with SU-8 & AgNW composite

Sanghyun,

Firstly, we used commercial samples from Cambrios in USA. Late on i synthesize my own AgNWs. There are a lot of publications you can follow. It is not very difficult. If you want to save time, you can buy some. So many companies supply AgNWs.

The work i did was not published. I did give a talk in an international conference. If you need more details, please feel free to ask.

Secondly, i would suggest to use IPA to wash PVP if possible because of high boiling point. Wash at least twice. I normally wash three times and then mix with SU8. U may need to add some compatible solvent to SU8.

Hope it helps

Xuhua

Xuhua Wang

Thanks so much. You helped me a lot. With following your suggestion, I wanna ask you two more details.

1) In washing process,

AgNP+IPA -> Vortexing -> Centrifuge

After Centrifuge, should I remove supernatant and refill with clean IPA? What if I keep using the IPA and mix it with polymer. Do you think that it would show critical problem?

2) When SU-8 is dissolved in IPA and dried, isn't threre any malfunction on its photo-sensitive characterisitc?

Hi

Go for Ag nano wire.

Dear Sanghyun,

In principle, for a conductive filled polymer composites, according to percolation theory, at a minimum concentration conductive filler that can form percolative conductive network is needed. Then, a higher aspect ratio ( the ratio of length/diameter for 1D, or lateral size/thickness in case of 2D) will be more easy to form a conductive network than 0D materials at the same concentration. It is therefore, in order to lower the necessary amount of conductive filler, the highest aspect ration filler should be the best. Then AgNW seems to be better to achieve the lowest concentration for percolation. I recommend you to try to use extremely high aspect ratio AgNW at relative low price which is commercialized online at https://ldmtpro.com/producs/ . A 16nm in diameter AgNW with length up to 80um which is dispersed in IPA or EtOH are available. For removing PVP, I re-command you to use hot ID water (60C) then, vortexing and than add an equal amount of acetone and centrifuge. AgNP+IPA -> Vortexing -> Add acetone-> Centrifuge : Repeat 3 times seems to be enough to remove most of PVP. If your photo curable resin is sensitive to water than use hot ethanol instead of water by a similar procedure.

Best