Amine-Based Latex Coatings for Indoor Air CO₂ Control in Commercial Buildings

Abstract

High levels of indoor air CO2 in commercial buildings can lead to various health effects, commonly known as sick building syndrome. Passive control of indoor air CO2 through solid adsorbents incorporated into the paint offers a high potential to handle CO2 without utilizing much energy. This study focuses on incorporating silica-supported aminopolymers into a polyacrylic-based latex that could be used as a buffer material for the passive control of CO2 in enclosed environments. To maximize the effect of the pigment (adsorbent), paints were all prepared at critical pigment volume concentration (CPVC) levels. CO2 at 800 and 3000 ppm were used to asses both low and high level contaminations. The removal efficiency of the surface coatings was evaluated within typical time frames (10 h for adsorption and desorption). Our laboratory-scale chamber results indicated that the silica-tetraethylenepentamine-based paint with 70 wt % loading exhibits the best adsorption performance, comparable to that of the powder-based sorbent, with only a ∼20% decrease in the adsorption efficiency. Our results also revealed that the optimization of paint formulation is critical in passively controlling indoor air CO2. The findings of this study highlight the potential of amine-based adsorbents as pigments in high PVC paints for indoor CO2 control in commercial buildings.

Passive Control of Indoor Formaldehyde by Mixed-Metal Oxide Latex Paints

“…The latex coatings were then used for passive control of indoor CO 2 , and the results demonstrated the efficacy of this buffering approach in offsetting high levels of indoor CO 2 in commercial buildings. 30 One of the significant challenges associated with this "smart paints" development approach is reduced kinetics of adsorption as a result of potential pore blockage by the latex. Thus, latex formulation should be optimized to minimize such kinetics barriers.…”

“…Each MMO-latex paint was synthesized using the methods described in our previous work. 30 The thickener, Cellosize QP 4400, was added to a mixture of propylene glycol and water. A basic pH was maintained by adding AMP 95.…”

“…Notably, relative to the adsorbent powders, the surface area and the pore volume of the coatings decreased by almost 90% for all samples, which could be attributed to the intrusion of latex into the silica pores and pore blockage by latex particles. 30 Nevertheless, despite such a dramatic reduction in pore volume and surface area, the MMO-latex paints were still considered to possess sufficient porosity and surface area for formaldehyde adsorption. Figure 3 depicts the OA and the corresponding CPVC values of the four MMO-latex paints.…”

Indoor CO2 Control through Mesoporous Amine-Functionalized Silica Monoliths

“…The concentration control of CO 2 at a safe level for a certain time, such as controlling it within 0.1% for 30 min, has been rarely discussed. 24 In this perspective, we developed an aminated silica monolith with a controlled mesoporous structure for lowconcentration CO 2 removal in the high humid condition. The amine-modified silica monolith (PEI x -silica) was prepared via a sol−gel method using PEI as a template agent.…”

“…Although a great advancement has been achieved on CO 2 adsorption using amine-modified silica, the research has mainly focused on the saturated CO 2 adsorption capacity of adsorbents. The concentration control of CO 2 at a safe level for a certain time, such as controlling it within 0.1% for 30 min, has been rarely discussed …”