Viologen-unit grafted organic-framework (iVOFm) by IISER

About  iVOFm-

• It can swiftly clean polluted water by soaking up sinister contaminants. 
• In general, commonly utilised sorbent materials often trap these pollutants through ion-exchange strategy to purify water but suffer from poor kinetics and specificity. 
• To mitigate this issue, our group prepared a newly engineered material called viologen-unit grafted organic-framework (iVOFm).
• The material employs amalgamation of electrostatics driven ion-exchange combined with nanometer-sized macropores and specific binding sites for the targeted pollutants. 

• The size and number of tunable macropores along with the strong electrostatic interaction of iVOFm can quickly remove various toxic pollutants from water.

• To develop this unique material, this team employed a make-and-break strategy to grow a charged porous organic polymer (POP) as a sponge-like infinite framework on silica nanoparticles that is used as a template. 
• Following this, the silica nanoparticles were strategically removed to create ordered hierarchical interconnected macro/microporosity throughout the material. 
• This material features inherent cationic nature and macroporosity to allow fast diffusion of pollutants. 
• When tested for a wide array of water pollutants, it showed ultrafast capture of all the pollutants — both organic and inorganic — with over 93% removal in just 30 seconds. 
• Among all the tested pollutants, the new material showed ultrafast removal of sulfadimethoxine antibiotic from water almost completely. 
• Even in the presence of other co-existing anions such as nitrates, chloride, and bromide, the removal of sulfadimethoxine antibiotic was extremely high within a minute. 
• The engineered material could remove sulfadimethoxine antibiotic with high efficiency when tested using different real water samples. 
• The fast pollutant trapping capacity is attributed to faster diffusion of pollutants through the ordered interconnected presence of macropores in the material. 
• They also found this material to be very selective toward toxic pollutants in presence of co-existing ions present in waste water even at low concentration. 
• It can also be used several times to clean contaminated water just like a bath sponge can be utilised to tackle multiple water spills. 
• This cationic compound is adaptable for sequestering various pollutants and is a possible solution to the water pollution problem.

Water pollutants-

Systematic studies have identified various organic (organic dyes, antibiotics, pesticides, etc.) as well as inorganic toxic pollutants such as iodides, oxo-pollutants like perrhenate that are carcinogenic in fresh water sources and can pose direct threat to humanity and living organisms.