Alexium International Group Limited is taking a different route into the data center cooling conversation, focusing not on moving heat faster but on giving buildings greater capacity to absorb it. The specialty chemistry company is making its microencapsulated phase change material (mPCM) technologies available to U.S. data center developers, design-build contractors and engineering firms as a passive thermal buffer integrated into building materials. The approach matters as AI infrastructure pushes thermal management beyond conventional equipment sizing and into the building envelope itself. Rather than treating walls, ceilings and support-room surfaces as passive boundaries, Alexium is positioning them as distributed thermal storage. The company offers three microencapsulation platforms under its NexTek, VivTek and Micronal brands, with formulations designed around different melting points and application requirements.

AI Data Centers Need More Thermal Headroom

The underlying engineering problem is becoming harder as AI racks increase the amount of heat concentrated inside increasingly dense computing environments. A cooling interruption no longer represents simply a temporary reduction in mechanical efficiency; it can quickly become a race between stored thermal energy and the time required to restore cooling. Schneider Electric has analyzed temperature behavior during cooling outages and found that dense data halls can experience temperature increases of roughly 5°C per minute, potentially reaching unacceptable conditions within minutes if cooling does not return. That creates a narrow operating window for chillers, pumps and other cooling equipment to resume service. Electrical rooms, UPS spaces, battery rooms and telecommunications areas face related requirements, while support spaces can experience substantial daily thermal swings.

Alexium’s technology approaches that problem through latent heat rather than conventional sensible thermal mass. Its mPCM technology places a proprietary phase-change core inside a cross-linked microcapsule shell, allowing the material to mix into familiar construction products without fundamentally changing installation practices. When surrounding air reaches the material’s phase-change temperature, the encapsulated material melts and absorbs heat. As conditions subsequently cool, the material solidifies and releases that stored thermal energy. This cycle allows a wall, ceiling, plaster layer or architectural coating to act as a thermal buffer without requiring a separate mechanical storage vessel. The distinction is important because the technology does not remove heat from the building. Instead, it delays the point at which rising temperatures become operationally significant, potentially creating additional time for cooling systems to recover.

Microencapsulated Phase Change Materials Move Into Construction

The Micronal platform gives Alexium a route into this market because BASF originally developed the material for construction applications. Alexium added Micronal to its portfolio through its December 2025 acquisition of Microtek Laboratories and now manufactures the material in the United States. The company says its broader microencapsulated PCM portfolio spans melting points from 6°C to 43°C, creating scope for different thermal environments rather than a single building-wide specification. That flexibility could become important for data center designers because the ideal switching temperature differs between a data hall, electrical room, battery space and active cooling system. A material designed to change phase too early could spend too much of its operating life charged, while one selected too high may provide little protection during a critical temperature excursion. The engineering question therefore shifts from simply adding thermal mass to choosing where and when that thermal mass becomes active.

Alexium cites a 15 mm gypsum board containing 3 kg/m² of Micronal as an example of the technology’s potential. According to the company, that configuration can store approximately 330 kJ/m² at its switching point, which it compares with the thermal-storage capacity of about 9 cm of concrete. The practical appeal comes from achieving that thermal capacity without constructing significantly heavier walls or floors. The company also says its capsules have undergone 10,000 thermal cycles without notable performance changes, representing roughly three decades of daily cycling. Such characteristics are particularly relevant to modular facilities, where designers have fewer opportunities to add substantial structural mass. The value proposition is therefore not simply higher thermal capacity but thermal capacity that can travel with a standardized construction system.

Where mPCM Could Fit Inside Data Centers

Alexium is targeting three broad application areas across data center infrastructure. In electrical, UPS, battery and telecommunications rooms, as well as network operations centers and offices, Alexium is positioning PCM-loaded board and plaster as potential thermal buffers, with Micronal grades available across switching temperatures that include the 23°C to 26°C range.The proposed application is intended to moderate temperature peaks and provide additional thermal buffering during cooling interruptions. In data halls, Alexium has specifically cited a 26°C phase-change grade for the data-hall envelope, positioning it as a material that can add latent thermal capacity as temperatures rise during a cooling interruption. Under normal conditions, the material would remain largely charged while providing latent thermal capacity as temperatures rise during a cooling interruption. Modular and edge facilities represent another potential application because lightweight construction generally provides less inherent thermal mass than conventional heavy structures.

The modular opportunity deserves particular attention as AI infrastructure becomes more distributed. Prefabricated facilities often prioritize transportability, rapid deployment and repeatable construction, which can constrain the amount of conventional thermal mass incorporated into the structure. An mPCM board could introduce additional heat-storage capacity in a lightweight construction system, while Alexium compares the thermal-storage capacity of a 15 mm PCM-loaded gypsum board with that of approximately 9 cm of concrete. That does not make the material a replacement for chillers, cooling distribution units or backup systems. Instead, it creates another layer between a cooling failure and an unacceptable operating condition. In a resilient architecture, that distinction matters because every additional layer can alter the amount of time available to diagnose an event and restore service.

Thermal Storage Becomes A Design-Stage Decision

Alexium is also opening a co-development program aimed at PCM-based thermal energy storage for peak-load management and ride-through applications. The program invites data center developers, MEP firms, cooling and thermal-storage OEMs, and manufacturers of boards and ceilings to develop applications around different physical formats and melting points. The company’s materials can be formulated into slurries, plates and cassettes for active thermal storage applications. SINTEF research has documented cases in which PCM-based thermal storage achieves greater compactness than conventional hot-water storage, including a specific system described as four times more compact. That potential changes the conversation for facilities where space, structural loading and deployment speed constrain conventional thermal storage.

The strategic significance extends beyond emergency ride-through. A thermal buffer can also influence how designers approach short-duration load changes, support-space HVAC sizing and the interaction between mechanical systems and building materials. If the building can absorb part of a temporary thermal surge, mechanical equipment does not necessarily need to respond to every short-lived fluctuation at the same intensity. That does not automatically translate into smaller cooling equipment because engineers must account for the duration, recharge requirements and operating envelope of the PCM system. It does, however, create another design variable for facilities where peak conditions increasingly determine infrastructure requirements. Thermal storage consequently moves closer to the front end of engineering decisions rather than remaining an add-on considered after the mechanical architecture has been established.

Alexium Wants Engineers Involved Before Construction

Alexium’s executives are framing the opportunity as an engineering discussion rather than a standalone materials sale. Billy Blackburn, CEO and Managing Director of Alexium, said: “The data center industry is asking a building-materials question – how can active temperature management solutions help minimize peak energy demand during extreme daily temperature swings. Alexium’s suite of PCMs are designed to meet these challenges and now vertically integrated for global manufacturing & distribution. We’re putting it in front of the developers, engineers and manufacturers who are building the data center & AI campuses of the next decade.”

Randall Lane, Alexium COO, emphasized the importance of tuning the material to the environment rather than treating PCM as a generic product. “Our microencapsulation platform is what lets us tune the melt point to the room – a 26°C grade for a data hall envelope, a custom point for a chilled-water loop,” he said. “That’s the conversation we want to have with engineers and OEMs now, while these facilities are still on the drawing board.”

That final point may determine whether mPCM becomes a meaningful component of AI infrastructure. Thermal storage works best when designers account for its operating temperature, charging conditions, discharge period, location and interaction with mechanical systems from the beginning. Alexium’s proposition is therefore less about replacing established cooling architecture and more about adding thermal inertia to an infrastructure stack increasingly defined by short response times and concentrated heat. For developers, the question is no longer simply how quickly cooling equipment can recover after a failure. It is also how much thermal capacity the building can provide before that recovery occurs.