Preparation of weather-resistant and heat-resistant waterborne acrylic coatings in high-temperature and high-humidity environments

In this paper, high-performance silica aerogel (SiO2 aerogel) thermal insulation coatings were obtained and profited from the excellent thermal insulation capability of SiO2 aerogel. The comprehensive properties and thermal insulation mechanism of the coatings were investigated via Scanning Electron Microscope (SEM), Fourier Transform Infrared Spectroscopy (FT-IR), contact angle, and temperature difference tests. Results showed that there was a contradiction between thermal insulation and mechanical property in this coating after the addition amount and proportion of silica aerogel, hollow glass microsphere, glass fibers, aqueous acrylic emulsion, and dispersing agents were optimized carefully. When the mass ratio of hollow glass to SiO2 aerogel microspheres was 1:1, the overall performance of the coating was the best with thermal conductivity of 0.050 W/(m·K) and adhesive strength of 1024 kPa.

SiO2 aerogel-embedded carbon foam composite with Co-Enhanced thermal insulation and mechanical properties

Thermal insulation of 3D printed complex and miniaturized SiO2 aerogels at medium-high temperatures

Improving thermal insulation of TC4 using YSZ-based coating and SiO2 aerogel

Electrospun SiO2 aerogel/polyacrylonitrile composited nanofibers with enhanced adsorption performance of volatile organic compounds

PurposeThe purpose of this study is to improve the mechanical properties, thermal insulation properties and flame retardant properties of polyethylene terephthalate (PET), the organic montmorillonite (OMMT)/SiO2 aerogel/PET composites and fibers were prepared, and the effects of the OMMT/SiO2 aerogel on the structure, thermal conductivity and flame retardance of the OMMT/SiO2 aerogel/PET composites and their fibers were systematically investigated.Design/methodology/approachThe OMMT/SiO2 aerogel/PET composites and fibers were prepared by in-situ polymerization and melt spinning using SiO2 aerogel as thermal insulation filler and OMMT (DK2) as comodified filler.FindingsThe experimental results showed that OMMT improved the crystallization properties of PET. Compared with the crystallinity of SiO2 aerogel/PET composites (34.8%), SiO2 aerogel/PET composites and their fibers reached 45.1% and 49.2%, respectively. The breaking strength of the OMMT/SiO2 aerogel/PET composite fibers were gradually increased with the OMMT content. When the content of OMMT was 0.8 wt.%, the fracture strength of the composite fibers reached 4.40 cN/dtex, which was 54% higher than that of the SiO2 aerogel/PET fiber. In addition, the thermal insulation properties of the composites and their fibers were improved by addition of fillers, and at the same time reached the flame retardant level. The thermal conductivity of the 0.8 wt.% OMMT/SiO2 aerogel/PET composites was 101.78 mW/(m·K), which was 49.3% and 58.8% lower than that of the SiO2 aerogel/PET composites and the pure PET, respectively. The thermal conductivity of the fiber fabrics woven from the 0.8 wt.% OMMT/SiO2 aerogel/PET composites was 28.18 mW/(m·K), which was 29.0% and 44.6% lower than that of the SiO2 aerogel/PET composite fiber fabrics and PET fiber fabrics. The flame retardancy of the composites was improved, with an limiting oxygen index value of 29.2% for the 0.8 wt.% OMMT/SiO2 aerogel/PET composites, which was 4.1% higher compared to the SiO2 aerogel/PET composites, and achieved the flame retardant level.Research limitations/implicationsThe SiO2 aerogel/PET composites and their fibers have good mechanical properties, flame retardant properties and thermal insulation properties, exhibited good potential for application in the field of thermal insulation, such as warm clothing. Nowadays, as the energy crisis is becoming more and more serious, it is very important to improve the thermal insulation properties of PET to reduce energy losses and mitigate the energy crisis.Originality/valueIn this study, PET based composites and their fibers with excellent mechanical properties, thermal insulation properties and flame retardant property were obtained by using three-dimensional network porous silica aerogel with low density and low thermal conductivity as the thermal insulation functional filler and two-dimensional layered OMMT as the synergetic modified filler.

SiO2 aerogel is a three-dimensional network structure solid materials, with the characteristics of low density, low thermal conductivity, high light transmittance, high porosity, high specific surface area and so on, but also has the excellent performance of fireproof and waterproof. It is a rare light, environmental protection, multifunctional material, which has great application prospects in the broad field of building thermal insulation. With the objective of building energy saving, this paper briefly describes the research on SiO2 aerogels, discusses the possibility of large-scale production from preparation of diverse raw materials, raw materials and drying cost reduction and so on, focuses on the application progress in building insulation of SiO2 aerogel glass and SiO2 aerogel thermal insulation coatings; then, from the point of view of the excellent characteristics, this paper presents the application of a SiO2 aerogel material in building energy saving technology, and from the SiO2 aerogel materials in thermal insulation, waterproof, fireproof and simplifying the construction process and other advantages, constructs the application system that SiO2 aerogel materials replace the current thermal insulation material in building energy saving. At last, it makes a conclusion and expectation of the SiO2 aerogel materials application prospect in building thermal insulation.

The hygroscopicity of building materials directly influences their thermal insulation performance, which is critical for achieving energy efficiency. Conventional materials, however, are limited by high moisture absorption, flammability, and poor thermal stability, rendering them inadequate for modern energy-saving needs. In this study, hydrophobic SiO 2 aerogel was incorporated into cement-based matrices to fabricate SiO 2 aerogel cement-based insulation boards (AIC) with enhanced thermal insulation properties. The investigation focused on how varying hydrophobic SiO 2 aerogel (SA) concentrations (0–50 vol%) affect the hygroscopic behavior of AIC under relative humidity (RH) conditions ranging from 0% to 95%. Furthermore, an isothermal adsorption model for moisture in SA cement-based materials was also established. Experimental results showed that under low to moderate humidity (RH ≤ 50%), the hygroscopicity of AIC was proportional to the SA concentration. At RH 30%, the water content increased from 1.25% in AIC0 (0 vol% SA) to 1.46% in AIC50. When RH exceeded 50%, 30 vol% SA marked the threshold between moisture absorption and hydrophobicity. When SA concentration was below 30 vol%, the hygroscopicity of AIC increases. At RH 70%, AIC20 had a water content of 6.67%, a 21% increase over AIC0 (5.51%). When SA concentration was above 30 vol%, the hydrophobicity of AIC is enhanced. At RH 95%, AIC40 showed a water content of 10.85%, a 20% reduction compared to AIC0 (13.5%). In addition, the hygroscopic equilibrium process of AIC was divided into three stages: the slow growth of monomolecular layer adsorption, the steady-state growth of multimolecular water film formation, and the rapid growth of capillary adsorption. For the first time, the Lewicki model is validated for hydrophobic composites, achieving exceptional accuracy (R 2 > 99%, SSE: 0.001–0.204, RMSE: 0.0002–0.2032) by integrating SA-induced pore coarsening and hydrophobic effects. These findings provide a theoretical foundation and data support for the application of AIC in diverse humidity environments.

ABSTRACTThe thermal insulation composite were prepared by blending aqueous polyurethane and modified SiO2 aerogel, and then coating to the surface of fabric. The influence of the content of SiO2 aerogel and polyurethane, crosslinking temperature and the particle size of SiO2 aerogel on thermal insulation rate of the composite fabric were detail analysis, the heat insulation, breathable, IR, SEM surface morphology of the composite fabric were evaluated. The thermal insulation rate of the SiO2 aerogel composite fabric is 28.97%, which is twice that of the original fabric. SiO2 aerogel composite fabric will have a wide range of application in the thermal insulation clothing, curtains, shoe materials, industrial equipment and building insulation, etc.

Thermal and acoustic performance evaluation of 3D-Printable PLA materials

Comparison of Dynamic Mechanical Properties and Thermal Conductivity of Unsaturated Polyester Composites Filled With Plain SiO2 Aerogel and Core-Shell SiO2 Aerogel

To prepare a base layer of thermal insulation for the surface of wind turbine blades, we utilized SiO2 aerogel material with a nanoporous structure as the thermal insulation layer of an inorganic composite photothermal de-icing coating. We further investigated the influence of raw material ratio and process on the thermal insulation layer’s performance. By adjusting the process parameters, the microstructure and characteristics of the SiO2 aerogel thermal insulation coating were controlled. Microstructure scanning and EDS analysis were employed to assess the results. The results of the experiment suggest that, as opposed to brush coating, atomized spraying is a better technique for creating SiO2 aerogel thermal insulation coating. The coating possesses excellent mechanical stability and applicability, maintaining a coating wear rate within 5% after 20 wear cycles under a load of 1734 N/m2, and the coating achieves the highest class 0 surface adhesion to the substrate surface. The coating exhibits exceptional heat insulation performance, reaching a temperature of 32.7 °C after five spraying cycles, which is 20.0 ∼ 29.4 °C higher than the surface without producing a complete heat insulation layer. The SiO2 aerogel aqueous slurry has a viscosity of 31.3 ∼ 36.9 mPa∙s, which is capable of forming a uniform membrane surface when sprayed at a 60° angle at 0.95 MPa pressure. Consequently, this paper’s design of photothermal thermal insulation offers strong anti-abrasion and excellent thermal insulation, presenting a new avenue for scientific investigation into coating photothermal de-icing.

Thermal stable, fire-resistant and high strength SiBNO fiber/SiO2 aerogel composites with excellent thermal insulation and wave-transparent performances

The unusually formation of porous silica nano-stalactite structure by high temperature heat treatment of SiO2 aerogel synthesized from rice hull

Thermal properties of carbon nanofibers enhanced lightweight cementitious composite under high temperature