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The use ofmesoporous silica materials as new hosts for stabilizing isothiazolinone-basedbiocides was investigated. Two types of porous matrices were synthesized:SBA-15 mesoporous silica and mesocellular siliceous foam (MCF). Thephysicochemical properties of the silicas (structure, textural properties) wereevaluated by SEM, TEM, XRD and adsorption/desorption of N2 in orderto determine their ability to encapsulate, stabilize and subsequently release acommercial biocide used for latex preservation (CMIT/MIT). CMIT/MIT consists ofan aqueous solution of the active ingredients CMIT (5-chloro-2-methyl-4-isothiazolin-3-one)and MIT (2-methyl-4-isothiazolin-3-one), present in a CMIT/MIT: 3/1 weightratio. It was observed that the biocide can be encapsulated in both silicaframeworks without suffering structural damage. The SBA-15 support exhibits alower adsorption capacity of biocide molecules than MCF, which may beattributed to both a greater MCF pore volume and pore size. MCF has lesshindered diffusion caused by a short channel length, which facilitates thebiocide access to the pores of the matrix. The long pore length of SBA-15 makesthe diffusion of CMIT/MIT mixture more difficult. Biocide release tests inaqueous media indicated that the CMIT/MIT concentration in the leachingsolution depends on the matrix nature, the smaller values being obtained whenthe ordered matrix was used. Additionally, biocide delivery could be delayed byincreasing the working pH from 7 to 9. Results showed that biocideencapsulation allows maintaining a long-lasting release, even under alkalineconditions (pH 9), at which the hydrolysis of non-supported CMIT occurs.Several release tests at different temperature (318, 323 and 328K), werecarried out for 20 days at pH 7. The biocide loading after the tests wasreflected in the IR spectra, and it has been corroborated that biocideencapsulation allows retarding the fast thermal decomposition of CMIT.