2. http://www.ilexikon.com/images/2/2b/Vitamin_B12.png Background: Effective size: 2.09 nm 2.09 nm Obtaining large bio-compounds: separation and purification process is very important Problems of commercial adsorbents: disordered pore structure Consequence: No optimal absorbing

3. Mesoporous carbon adsorbents: CMK-n (n: 1 to 9) Advantages on adsorbing: 1. High specific surface area: around 1300 m 2 /g. Large pore volume: around 0.8 cm 3 /g 2. Ordered nano porous structure (around 3 nanometres). Synthesis of mesoporous carbon: Hard template method: employing mesoporous silicate as a template. Mesoporous silicate: synthesized by sol-gel method employing tri-block co-polymer as a template. Background: Zhao DY, Feng JL, Huo QS, Melosh N, Fredrickson GH,Chmelka BF, et al. Science 1998;279(5350):548–52. Ryoo R, Joo SH, Jun S. J Phys Chem B 1999;103(37):7743–6.

4. Points worth mention: Coating of polymer PMMA (polymethyl methacrylate) on the surface of mesoporous channels to increase the compatibility between adsorbent and guest molecule. Factors matters to capacity of adsorbents Physical: right pore size and big pore volume and specific surface area. Chemical: proper surface chemical properties for guest molecules http://www.jergym.hiedu.cz/~canovm/polymery/polymera/pmma.gif Their idea:

5. Points worth mention:

6. Structural characteristics of the different carbons tested

7. Points worth mention: They controlled the coating of PMMA on mesoporous carbon to be same.

8. Points worth mention:  Adsorption of VB12 on the different adsorbents as a function of contact time.

9. IR spectra of (b) PMMA, (c) CMK-3-PMMA, (e) CMK-3-PMMA-VB12 in the C=O stretching region between 2100 and 1400 cm1. Points worth mention:  Justification of hydrogen bond between B12 and PMMA:

10. Conclusions: The VB12 adsorption capacities of the adsorbents depended on the BET surface area as well as mesoporous volume and pore diameter of the adsorbents. After coating with PMMA, they all exhibited higher adsorption than their initial mesoporous carbons. That was due to the formation of hydrogen bonding between PMMA on the mesoporous carbons surface and VB12 molecules. The adsorption properties were mostly influenced by the surface properties and the pore structure.