Colloquium: Nanotechnology in Civil Engineering - Questions/Discussions

Replies

• 

  CIVILPRINCESS

  hello every one 😁
  
  why no queries or comments in this paper...?:neutral:
  
  i am waiting for your questions.....
  
  if no questions, i would appreciate it if you left a feedback on the presentation...... :smile: :smile: :smile:
  
• 

  madhumurundi

  hi,
  Field you took for Seminar is So good 😛
  Now a days every where Nanotechnology is adopting.. these things are still in research.. but when it comes to the your presentation.. you covered almost all part how Nano Technology can be used ??
  my question is: 1. Is it so Affordable 😕 😕
  2. Which Type of the Carbon nano tubes(CNT's) you are using .. Single or MultiWalled 😕 😕
• 

  CIVILPRINCESS

  madhumurundi

  hi,
  Field you took for Seminar is So good 😛
  Now a days every where Nanotechnology is adopting.. these things are still in research.. but when it comes to the your presentation.. you covered almost all part how Nano Technology can be used ??

  Yes the nano technology is gaining momentum throughout the world.:smile:
  And my paper is just covering its uses in the field of civil engineering.
  
  

  2. Which Type of the Carbon nano tubes(CNT's) you are using .. Single or MultiWalled 😕 😕

  i have already mentioned this in my ppt in slide #13.
  Oxidized multi-walled nanotubes (MWNT’s) show the best improvements both in Compressive strength (+ 25 N/mm2) and flexural strength (+ 8 N/mm2) .It is theorized the high defect concentration on the surface of the oxidized MWNTs could lead to a better linkage between the nanostructures and the binder thus improving the mechanical properties of the concrete.
  
  
  
  

  1. Is it so Affordable 😕 😕

  the cost varies with the fields it is used in....
  CONCRETE:
  The cost of adding CNT’s to concrete may be prohibitive at the moment (carbon nanotubes cost 20-1000€/gram), but work is being done to reduce their price and at such time the benefits offered by their addition to cementitious materials may become more palatable.
  
  STEEL
  As far as the steel industry is concerned the products (MMFX2 steel) now available at the markets are at a comparatively lower price.
  
  GLASS
  as far as the glass industry is taken into account it is a little costlier compared to the conventional glass but the research in the nanotechnology field promises to make these products available at a lower prices .
  
  WOOD INDUSTRY
  In the broader sense, nanotechnology represents a major opportunity for the wood industry to develop new products, substantially reduce processing costs, and open new markets for biobased materials.
  
  FIRE RESISTANCE
  nano technology as a method of increasing fire resistance is a cheaper option than conventional insulation.
  
  
  hope i have satisfied all your questions.....😁
  
  do leave more queries if any.........
• 

  CIVILPRINCESS

  @madhumurundi have i cleared your doubt?
  
  and others this paper is not restricted to civil engineers awaiting questions from you people.... 😁
  
  and where are the civil engineers?........waiting to have a good discussion with you guys in this topic..... 😁
  
  cheers
• 

  madhumurundi

  hi,
  I am very much happy you answered my all the queries in Very Elegant way and also your answers filled with full explanation... Good Man..
  Keep Walking in a Good Way
  
• 

  cooltwins

  hey civil princess,
  
  nice presentation...... 😛
  a rare topic i should say....😀
  and justice done to the topic...
  
  and my question is :
  what is the practical use of a steel that can resist a temperature of 1000 degree. any way the temperature of a building is not going to be so much....
  and this is for the civil field only i don't want answers regarding furnaces.....😉
  looking forward to your reply
  forgive my ignorance
• 

  just2rock

  for CNT or related articles etc ou may can step down to my blog
• 

  CIVILPRINCESS

  cooltwins

  what is the practical use of a steel that can resist a temperature of 1000 degree. any way the temperature of a building is not going to be so much....
  and this is for the civil field only i don't want answers regarding furnaces.....😉

  Nano materials are making the skyscrapers safer.😁
  
  The problem for the World Trade Center was that regular steel:
  Above 750 F, steel starts to lose its structural integrity, and at 1100 F, steel loses 50 percent of its strength.
  
  A new formula infuses steel with nanoscale copper particles, this formula could maintain structural integrity at temperatures up to 1000 degrees F.
  
  if this technology had then existed then,the world trade center would not have collapsed like a pack of cards.....the damage would be restricted to the top floors which suffered the strike and the rest of floors would not have collapsed.... that would have caused less damage..
  
  hope i have cleared your doubt......
  do leave questions if any....😀
• 

  cooltwins

  good explanation...😁
  
  and in slide no.29 you have mentioned about carbon monolithic aerosols.....
  could you explain its production and how do you dispose it off(in the sense would the aerosol be stuck with the pollutants?) .....😕
• 

  CIVILPRINCESS

  cooltwins

  and in slide no.29 you have mentioned about carbon monolithic aerosols.....
  could you explain its production and how do you dispose it off(in the sense would the aerosol be stuck with the pollutants?) .....😕

  the production of the aero gels is as follows:
  

  • Production of Aero gels is done by sol-gel process.
  • the principle involved is
    
    First a gel is created in the solution and then the liquid is carefully removed to leave the aero gel intact.​
  • The first step is the creation of the colloidal solution of solid particles known as “sol”. Carbon Aero gel is made by the creation of colloidal carbon.
  • The process starts with a liquid alcohol like ethanol, which is mixed with a silicon alkoxide precursor, for example tetramethyl orthocarbonte (TMOS) or tetraethyl orthocarbonte (TEOS).
  • The oxide suspension begins to undergo condensation reaction which results in creation of metal oxide bridges linking the dispersed colloidal particles.
  • When this interlinking has stopped the flow of liquid within the material, this is known as gel.
  • Basic catalysts tend to produce more transparent with less shrinkage. The removal of the liquid from a true aero gel involves special processing.
  • By increasing the temperature and pressure the liquid is forced into a supercritical fluid state where by dropping the pressure it could instantly gasify and remove the liquid inside the aero gel, avoiding damage to delicate three-dimensional network.
  • While this can be done with ethanol, the high temperatures and pressures lead to dangerous processing conditions. A safer, lower temperature and pressure method involves a solvent exchange.
  • The end result of either process removes all liquid from the gel and replaces it with gas, without allowing the gel structure to collapse or lose volume.
• 

  CIVILPRINCESS

  The main advantage of using a carbon aero gel is adsorption properties of hydrophobic Carbon aero gel remain stable even after 20 adsorption/desorption cycles.
  
  Self indicating Carbon gels when become saturated can be regenerated by heating at 100-120oC until they return to their original colours. The heating literally drives off the adsorbed moisture. Regeneration can be carried out repeatedly, although eventually the crystals will lose their colour. When regenerating self indicating Carbon gel sachets, only the minimum necessary heat can be used. This will prevent the sachet material from deteriorating. Although non-indicating Carbon gel can be regenerated in exactly the same way, it is not apparent when the Carbon gel is regenerated other than by checking its weight-it will return to its original dry weight when completely regenerated.
  
  THE PROCESS:
  
  
  (1) Carbon Aero gels are heated to a temperature of 100-120oC and return back to their original colour.
  (2) washing with an extract of organic compounds and removing volatile organic materials remaining thereafter,
  (3) Oxidation to oxidize organic compounds remaining and, preferably, bleach the material;
  (4) Washing with an acid to remove soluble inorganic matter;
  (5) Heating to dry the material and combust any remaining organic compounds present and recovering the regenerated material.
  
  
  Hope i have answered all your questions.....
  do leave more questions if any.😁