Nano-porous structure

Introduction In today’s world where energy conservation and carbon emission control are increasingly valued, thermal insulation materials play a crucial role in both industrial and civil applications. Among a wide range of insulation materials, fumed silica—with its unique nanostructure, ultra-high specific surface area, and exceptional thermal insulation performance—is gradually becoming an indispensable core material in the thermal insulation industry. Moreover, vacuum insulation panels (VIPs) and high-performance insulation boxes made from fumed silica are demonstrating broad application prospects across multiple fields, including cold chain logistics, biopharmaceuticals, and fresh food preservation.   I. The Thermal Insulation Mechanism of Fumed Silica Fumed silica is an amorphous nano-scale powder material produced through the high-temperature hydrolysis and condensation of silicon halides. Its primary particle size is only 7–40 nm, and its specific surface area can reach as high as 400 m²/g. Its excellent thermal insulation performance mainly stems from the following aspects: First, the nano-porous structure. Fumed silica particles are connected by hydrogen bonds and van der Waals forces, forming a stable three-dimensional dendritic network structure. A large number of micro- and nano-scale air pores exist within and between the particles. Air itself is a poor conductor of heat, and these tiny pores effectively disrupt the continuity of heat conduction pathways, thereby significantly reducing the material‘s thermal conductivity Second, the interfacial scattering effect. Numerous interfaces are formed between fumed silica nanoparticles and the base material. These interfaces scatter heat flow, effectively increasing thermal resistance and impeding heat transfer. Third, infrared radiation blocking. The particle size of fumed silica is close to the wavelength of infrared thermal radiation, enabling strong scattering of infrared photons and blocking heat transfer through radiation. This infrared scattering effect is particularly significant in medium-to-high temperature environments.   II. Vacuum Insulation Panel (VIP): The Star Application of Fumed Silica Vacuum insulation panel (VIP) is one of the most important application forms of fumed silica in the thermal insulation field. VIP primarily consists of three parts: the core material, the high-barrier envelope, and the getter. The choice of core material is the key factor determining VIP performance. Compared to traditional core materials such as glass wool and microsilica, fumed silica offers clear advantages in terms of manufacturing cost, production efficiency, thermal stability, and service life. VIPs with fumed silica as the core material can achieve a thermal conductivity as low as 0.004–0.005 W/(m·K) (i.e., 4–5 mW/m·K), offering 5 to 10 times better thermal insulation performance compared to conventional insulation materials such as polyurethane foam. At the same time, VIPs are only 1/5 to 1/10 the thickness of traditional insulation materials, achieving a thinner, lighter product that provides a slimmer insulation layer, larger usable space, and lower overall weight for insulated chambers. More notably, even if a VIP loses its vacuum under extreme circumstances, the fumed silica core material itself still provides good thermal insulation performance, outperforming most other insulation materials. This means that VIPs using fumed silica cores offer higher reliability and longer service life—some high-quality fumed silica core VIPs can last for 50 years or more.   III. Application Scenarios: From Cold Chain Logistics to Pharmaceutical Transport Thanks to the exceptional thermal insulation performance of VIPs, fumed silica is widely used in various thermal insulation scenarios. In the field of cold chain logistics, insulation boxes using fumed silica VIPs as the core insulation material are gradually replacing traditional EPS (expandable polystyrene) foam boxes and are becoming the new benchmark in the industry. Taking cold chain insulation boxes as an example, with VIPs (using nano-scale fumed silica as the core material) as the insulation material, less dry ice is needed to achieve longer temperature retention under the same conditions, effectively reducing energy consumption and costs. Meanwhile, the internal temperature inside the box is more stable and evenly distributed, ensuring product quality and safety during transport. In the pharmaceutical cold chain field, the application of fumed silica VIPs is particularly significant. Temperature-sensitive biopharmaceuticals such as mRNA COVID-19 vaccines require storage and transport under extremely low temperatures of -70°C. VIP insulation boxes containing fumed silica use passive cooling methods without the need for external power, achieving precise temperature control and preventing temperature fluctuations, thus becoming a key link in ensuring the integrity of the vaccine supply chain. The core advantages of fumed silica VIPs in low-temperature transport include: Reliable passive cooling without external energy supply Reduced energy consumption and CO₂ emissions Slim-wall design increases transport and storage capacity by up to 20% Lightweight for easy portability Service life exceeding 30 years, offering sustainability In addition, fumed silica VIPs are widely used in household refrigerators, yacht refrigerators, car refrigerators, deep freezers, electric water heaters, vending machines, building wall insulation, LNG storage and transport, and many other fields. It can be said that wherever efficient thermal insulation and energy saving are required, fumed silica is present. IV. Market Trends and Prospects The global fumed silica market is experiencing steady growth. According to market research data, the global fumed silica market is expected to grow from USD 1.80 billion in 2025 to USD 2.14 billion by 2030, at a compound annual growth rate (CAGR) of approximately 3.46%. Meanwhile, the fumed silica vacuum insulation panel (VIP) sub-market is performing particularly well: the global fumed silica VIP market was valued at approximately USD 296 million in 2024 and is projected to reach USD 536 million by 2031, with a robust CAGR of 9.2%. The main drivers of this growth include:   Growing global emphasis on energy efficiency and sustainable development Increasingly stringent mandatory standards for building energy efficiency imposed by governments worldwide Rapid development of cold chain logistics, especially in the biopharmaceutical sector Rising demand for efficient thermal management materials in the new energy vehicle industry V. GESEE‘s Product Solutions Zhengzhou Gesee New Materials Co., Ltd. (GESEE) has been deeply engaged in the field of fumed silica for many years, committed to providing high-quality fumed silica products and solutions to customers worldwide. GESEE’s fumed silica products are divided into hydrophilic and hydrophobic types to meet the diverse needs of different application scenarios. GESEESIL-200 is GESEE‘s flagship hydrophilic fumed silica product, with a specific surface area of 200 m²/g and a silica content exceeding 99.8%. It features small particle size, large specific surface area, good thermal stability, and low moisture content, and is widely used in rubber, sealants, plastics, resins, paints, inks, pharmaceuticals, cosmetics, food, and many other industries.   In the field of thermal insulation, GESEE‘s fumed silica products, with their excellent thermal insulation performance and stable quality, serve as ideal raw materials for high-end insulation products such as thermal insulation coatings, vacuum insulation panels, and nano-porous insulation materials. GESEE also has its own branded line of insulation boxes, combining its high-quality fumed silica with advanced vacuum insulation technology to provide efficient and reliable thermal insulation solutions for applications such as cold chain logistics, pharmaceutical transport, and fresh food delivery. Conclusion With its unique nanostructure and exceptional thermal insulation performance, fumed silica is profoundly transforming the landscape of the thermal insulation industry. From vacuum insulation panels to cold chain insulation boxes, from building energy conservation to pharmaceutical transport, this “industrial seasoning“ is increasingly entering our production and daily life. GESEE will continue to deeply cultivate the fumed silica field, contributing to the high-quality development of the thermal insulation industry and playing its part in the global cause of energy conservation and emission reduction, through high-quality products and professional services. This article is contributed by Zhengzhou Gesee New Materials Co., Ltd. (GESEE). For more product information, please feel free to contact us.