Messi Biology states that a typical formulation challenge in composite disinfectants is that active oxygen oxidizers—such as hydrogen peroxide and peracetic acid—are supposed to be more stable under acidic conditions. However, once they coexist with acidic components for a long time, coupled with the presence of trace metal impurities, they undergo slow decomposition. This leads to the attenuation of active ingredients, gas generation resulting in bottle bloating, and a shortened shelf life. Nano-magnesium carbonate precisely plays a “multi-role” stabilizing part in this system.
Magnesium carbonate (MgCO3) is a weakly alkaline carbonate, slightly soluble in water, and only gradually dissolves upon encountering acid to release Mg2+ and CO2. This “slow-response” characteristic is what distinguishes it from strong alkalis (such as NaOH): it neither alters the system pH instantaneously nor fails to continuously neutralize excess free acid. Its nanoscale particle size (approximately 20–65 nm) provides an extremely high specific surface area and abundant pore structure, offering ample geometric space for encapsulation and adsorption.
Triple Stabilization Mechanism in Acidic/Oxidizing Disinfectants
First tier: Weakly alkaline buffering to stabilize the system pH. Hydrogen peroxide is most stable below pH 4.5; once the pH rises, its decomposition accelerates sharply. However, peracetic acid also suffers losses in a slightly acidic environment due to the hydrolysis equilibrium shifting toward acetic acid and hydrogen peroxide. Nano-magnesium carbonate acts like tiny “pH buffer capsules” in the system, dissolving slowly and adjusting precisely to maintain the system within the optimal range where peroxy bonds are not easily broken.
Second tier: Capturing metal ions to cut off the free radical chain decomposition. Trace transition metals such as Fe3+, Cu2+, and Mn2+
are the “number one killers” of active oxygen disinfectants. They catalyze the homolytic cleavage of peroxy bonds via Fenton-like reactions, generating ⋅OH free radicals and triggering self-accelerating decomposition. Mg2+
has been proven to inhibit the catalytic activity of iron and copper, capturing peroxy anion free radicals and interrupting the free radical chain reaction. The Mg2+ released by the dissolution of nano-magnesium carbonate performs this “chelation-inactivation” function, delaying the decomposition of active oxygen from the source.
Third tier: Porous encapsulation to physically isolate active components. By virtue of its high porosity, nano-magnesium carbonate can form a “protective microcapsule” layer on the surface of oxidant particles or droplets, weakening the direct contact interface between the acid and the oxidant, and reducing the cleavage rate of peroxy bonds. This shares the same logic as carriers in drug sustained-release systems—by regulating particle size and porosity, the release rhythm of active ingredients can be precisely controlled.
In practical formulation, the addition amount of nano-magnesium carbonate is not simply “the more, the better.” Too little is insufficient to capture metal impurities or neutralize free acids; too much may push the system pH past the threshold, triggering oxidant decomposition instead. It is recommended to start from the bench-scale stage with an increment of 0.1%–1% for screening, focusing on three indicators: the decay curve of available oxygen content over time, the pH drift magnitude of the system, and the gas pressure change during storage period. Meanwhile, surface modification requires attention—pretreatment with anionic dispersants such as sodium polyacrylate or sodium hexametaphosphate can enhance the suspension stability of nano-magnesium carbonate in acidic systems, preventing agglomeration and sedimentation.
The “weakly alkaline, slow-dissolving, high specific surface area, and ion-capturing” four-in-one characteristics of nano-magnesium carbonate make it an ideal stabilizer carrier for acidic/oxidizing composite disinfectants. Compared to the potential silica scale problems caused by traditional silicate stabilizers and the environmental burdens of organic chelating agents, magnesium carbonate can degrade into Mg2+ and CO2, making it green and safe. With the further maturation of nano-encapsulation and surface modification technologies, this material will have broader application prospects in solid disinfectants, sustained-release active oxygen formulations, and even high-end medical disinfection fields.