Aerogel: MGDA & EDC

Week #08: The New Chemicals For The Water Filter

Carlos Manuel Jarquín Sánchez
4 min readSep 23, 2022

Preface ✨

Hello everyone!

My intentions for writing these articles are:

  • Explain technical information about aerogels in simple terms (to the public)
  • Store information and habits for my future self and others (in <7 minutes)

Coolio? Sweet. Enjoy the series :-)

Why The New Changes? 📈

Alginate does have its setbacks.

There are two choices:

  • Make a filter that’s favorable to the effectiveness of heavy metal ion removal
  • Make a filter that’s favorable to the efficiency of the environment and people

Perhaps it’s best to be more efficient and environmentally friendly to nature & society… even if it means sacrificing a smidge of the filter's effectiveness.

Our previous chemical cannot degrade rapidly in the environment once the filter is disposed of.

The chemical is EDTA [Ethylenediaminetetraacetic Acid]

EDTA Raw Chemistry

This chemical has 4 oxygen atoms & 2 nitrogen atoms that could bond with heavy metal ions in the form of chelation. But the time to degrade in the environment and potable water is over 4 days. EDTA’s effects on the human body are reproductive damage and human development roadblocks when orally consumed.

EDTA would have been the base of the filter. EDTA would have to touch the water to remove the heavy metal ions. And that water would be consumed by the people using the filter. BIG NO-NO.

So what is the new chemical, Carlos?

Welcoming MGDA: The New Saviour 🌠

Methylglycinediacetic Acid Trisodium Salt [MGDA-Na3] is the new compound that will set the base for the filters!

It can target and adsorb heavy metal ions via chelation without environmental consequences. The chemical can withstand higher temperatures in the real world and maintain quality stability throughout the entire pH range.

MGDA-Na3 has a high rate of biodegradation at over 68% after approximately 12 days exposed to the environment.

MGDA-Na3 Raw Chemistry

This material has 3 oxygen atoms & 1 nitrogen atom that could bond with heavy metal ions in the form of chelation.

You may notice that EDTA has more atoms that can bond with heavy metal ions than MGDA-Na3. This is the reason why EDTA is more effective at the task of purifying water faster than MGDA-Na3.

EDTA vs. MGDA | The numbers indicate the probability of the heavy metal ion staying onto the chemical

But MGDA-Na3 is listed on EPA’s Safer Chemical Ingredients List in the United States. This means it will not affect an individual who drinks water filtered by MGDA-Na3!

But how is that possible?

Most of it comes down to its chemistry. Notice that MGDA-Na3 has a methyl group (CH3). This chemical group repels water from touching the chemical; It is hydrophobic. This creates the chemical to have water-repelling tendencies/behaviors.

MGDA-Na3 cannot affect the quality of the water if the chemical does not want to interact with the water.

MGDA-Na3 Wins.

What About EDC? ☑️

EDC is an abbreviation of the chemical compound:

1-Ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride

EDC Raw Chemistry

EDC will act as a coupling agent. It will bond the base material (MGDA-Na3) with Sodium Alginate & DETA (another cross-linker).

EDC is one of the few carbodiimides that is water-soluble (dissolves in water) and can create a new compound/material. Some of its advantages are that the pH range of EDC is between 4.0 to 6.0. This pH range is equivalent to the pH of most water on Earth.

EDC is also used as a carboxyl activating agent for the coupling/bonding of primary amines to yield amide bonds.

Sodium Alginate contains carboxyl groups (-COOH) & DETA contains amine groups (NH2) for EDC to combine and create amide bonds (C=O-NH2).

This can “supercharge” the adsorption of the filter and create a similar effectiveness rate of EDTA!

Primary Amide Groups

The letter “R” in the chemical means that the molecule is either a hydrogen atom or a hydrocarbon (like methyl, CH3).

The reaction functions perfectly at room temperature and yields >80% effectiveness when converting carboxylic acids + amines into amides.

EDC Is Go.

Connect →🔗



© 2023 by Carlos Manuel Jarquín Sánchez. All Rights Reserved.