Electrospinning Machine| Highly Flexible Oxide Ceramic Luminescent Membranes against Extreme Temperatures

On the track of "high-temperature luminescence" for flexible photoluminescent materials, the latest work by Zhang Kun's team from Xi’an Polytechnic University, published in Advanced Optical Materials, has pushed the high-temperature resistance limit for flexible visible luminescence to 375°C. For the first time, they used X-ray total scattering measurements to capture high-definition microstructural details of the "flexibility + high-temperature luminescence" mechanism in amorphous ceramic nanofibers. Master's student Mu Dan is the first author and has now joined Xianyang Normal University.

As a type of optical material adaptable to complex curved surfaces, flexible photoluminescent materials have irreplaceable application value in extreme environment monitoring, specialized equipment visualization, and high-temperature device labeling. However, the service performance of traditional flexible photoluminescent materials under extreme conditions has significant limitations, mainly in three aspects:

1. High-temperature resistance bottleneck of the substrate: Conventional flexible polymer substrates have poor high-temperature resistance; even specially designed organic polymers struggle to operate for extended periods above 300°C, unable to meet the demands of extreme scenarios such as aerospace.

2. Difficulty in controlling luminescence uniformity: Uneven dispersion of luminescent centers leads to poor luminescence uniformity at high temperatures.

3. High-temperature luminescence quenching effect: When temperatures exceed 200°C, traditional flexible luminescent materials often experience a sharp decline in luminescence intensity (quenching), severely limiting their luminescence applications in extreme environments.

Therefore, there is an urgent need for breakthrough progress in the field of flexible photoluminescent materials with extreme temperature stability to advance the development of flexible luminescent devices.

To achieve stable luminescence across an ultra-wide temperature range while maintaining excellent mechanical properties, the team employed electrospinning combined with subsequent calcination to successfully prepare flexible amorphous Sm₂O₃-La₂O₃-ZrO₂ (SLZ) nanofiber membranes, providing a new paradigm for the development of flexible high-temperature photoluminescent devices. The core advantages of this flexible luminescent nanofiber membrane are as follows:

Luminescence without fading across an ultra-wide temperature range: From low temperatures of -12°C to high temperatures of 375°C, the red light brightness and color remain almost unchanged, covering the temperature range of most extreme application scenarios.

Unaffected by high-temperature "baking" tests: After continuous heating at 375°C for 24 hours, the material showed no structural cracking or wrinkling, and no significant decline in luminescence brightness, addressing the weakness of traditional materials being prone to aging at high temperatures.

Stable luminescence after repeated bending: After multiple bending tests, the material’s excellent mechanical properties were maintained; even in folded or stretched states, the luminescence function remained completely unaffected, significantly outperforming most flexible luminescent materials.

The "hardcore" confidence of this membrane material comes from its unique amorphous nanofiber structure:

1. Short-range order—stable luminescent centers: Strong short-range order indicates the formation of [SmO] polyhedra and rigid local coordination structures, ensuring the environmental stability of luminescent centers (Sm³⁺), thus guaranteeing photoluminescence stability and laying the foundation for luminescence uniformity.

2. Medium-range order—luminescence and mechanical reinforcement: The continuous structure of [Sm₃]-O-[Sm₃] medium-range order inhibits the destruction of coordination environments at high temperatures, effectively reducing luminescence quenching; simultaneously, it enhances the toughness of amorphous oxides, improving mechanical strength and deformation resistance.

3. Long-range disorder—flexibility enhancement through amorphous structure: Long-range disorder avoids the "weak planes" (easily fractured atomic planes) formed by long-range ordered atomic arrangements in crystalline materials, significantly reducing brittleness and enhancing flexibility and fracture resistance, enabling adaptation to mechanical stress in extreme environments.

This study developed a luminescent membrane of amorphous oxide ceramic nanofibers resistant to extreme temperatures, overcoming the limitations of traditional photoluminescent materials and setting the highest visible luminescence temperature record for flexible photoluminescent materials. It is the first to reveal the critical role of short/medium-range ordered structures in amorphous ceramic nanofibers on performance. Amorphous ≠ chaotic; its amorphous structural design provides a new approach to solving the synergistic control challenge of "high temperature-flexibility-luminescence stability." The SLZ nanofiber membrane’s ultra-wide temperature range luminescence stability, high-temperature mechanical reliability, and excellent flexibility are expected to drive breakthroughs in applications of flexible optical devices in extreme environment monitoring, high-temperature device visualization labeling, and specialized protective equipment, providing important experimental basis and theoretical support for the functional expansion of flexible optoelectronic materials.

【Original link】D. Mu, W.-D. Han, X. Mao, C.-K. Liu, B. Ding, Y.-Y. Wang, Kun Zhang, Highly Flexible Oxide Ceramic Luminescent Membranes against Extreme Temperatures. Adv. Optical Mater. 2025, e01125. https://doi.org/10.1002/adom.202501125