Balancing Hydrophobicity and Water-Vapor Transmission in Sol–Silicate Coatings Modified with Colloidal SiO2 and Silane Additives

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21110%2F25%3A00386767" target="_blank" >RIV/68407700:21110/25:00386767 - isvavai.cz</a>

Result on the web

<a href="https://doi.org/10.3390/surfaces8040088" target="_blank" >https://doi.org/10.3390/surfaces8040088</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3390/surfaces8040088" target="_blank" >10.3390/surfaces8040088</a>

Result language

angličtina

Original language name

Balancing Hydrophobicity and Water-Vapor Transmission in Sol–Silicate Coatings Modified with Colloidal SiO2 and Silane Additives

Original language description

This study investigates the optimization of sol–silicate façade coatings modified with colloidal silica and a silane-based hydrophobizing additive to enhance hydrophobicity while maintaining a high water-vapor transmission rate (V). The effects of the binder ratio between potassium water glass (WG) and colloidal silica (CS), the type of colloidal silica (unmodified or epoxy-silanized), and the concentration of the hydrophobizing additive (HA) were systematically evaluated. Water-vapor transmission was determined according to EN ISO 7783, and surface wettability was measured before and after accelerated UV-A aging. Dynamic viscosity was monitored for two years to assess long-term storage stability. The optimized formulation contained 7 wt % potassium water glass, 15 wt % colloidal silica, and 1 wt % hydrophobizing additive. It exhibited stable viscosity over time (~19,000 mPa.s after six months), high water-vapor transmission (V > 6700 g.m-2.d-1, class V1), and an initial contact angle of 118°, which decreased only moderately after UV-A exposure. Coatings containing epoxy-silanized colloidal silica showed slightly lower transmission but still remained within the high V range suitable for vapor-open façade systems. The results confirm that balanced sol–silicate systems can combine durable hydrophobicity with long-term rheological and functional stability.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

20506 - Coating and films

Project

<a href="/en/project/GA24-10395S" target="_blank" >GA24-10395S: Essential oils as new biocides in construction coatings</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2025

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Surfaces

ISSN

2571-9637

e-ISSN

—

Volume of the periodical

8

Issue of the periodical within the volume

4

Country of publishing house

CH - SWITZERLAND

Number of pages

19

Pages from-to

1-19

UT code for WoS article

001648592100001

EID of the result in the Scopus database

2-s2.0-105026069996