Spray Drying Techniques for Particle Morphology Control

Spray drying has emerged as a versatile process for engineering particle morphology across food, pharmaceutical and advanced materials sectors. The technique relies on atomising a liquid feed into fine droplets, which are rapidly dried by a hot gas stream. Control over particle size, internal structure and surface characteristics is achieved by tuning parameters such as feed composition, droplet size distribution, inlet and outlet temperatures, and residence time. Fundamental mechanisms governing morphology include solute redistribution, skin formation, phase separation and capillary instabilities. The Péclet number quantifies the balance between convective transport of solute and diffusive relaxation within the droplet, predicting whether particles will be hollow, dense or wrinkled. Formulation variables such as polymer or protein concentration influence viscosity and glass transition behaviour, determining the moment at which the droplet “locks” into a given shape. Atomiser design and operating pressure affect initial droplet diameter and collision dynamics, while humidity and drying‐kinetic profiles steer internal porosity and surface roughness. Single‐droplet studies now underpin predictive models, linking laboratory‐scale observations to pilot‐scale and industrial applications. By combining mechanistic insight with advanced in situ characterisation—such as thermography, optical coherence tomography and high‐speed imaging—researchers can rationalise the development of agglomerates, spray‐dried granules and functional supraparticles. Optimised morphology yields powders with tailored flowability, solubility, release kinetics and compressibility, meeting stringent specifications in inhalable therapies, instant beverages, catalysts and sinterable ceramics.

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Spray Drying Techniques for Particle Morphology Control publication trend

The graph below shows the total number of articles in spray drying techniques for particle morphology control across all publications each year (not limited to Nature Index journals).

Technical terms

Atomisation: The process of converting a liquid feed into fine droplets using mechanical or pneumatic means, determining the initial droplet size distribution.

Péclet number: A dimensionless ratio expressing the relative rates of solute convection to diffusion within a drying droplet, predictive of particle internal structure.

Locking point: The moment during drying when the droplet surface vitrifies or gels, fixing the overall morphology and limiting further shape evolution.

Agglomeration: The formation of particle clusters through collision and adhesion of primary particles, influencing bulk flowability and reconstitution behaviour.

References

1. Single droplet drying with stepwise changing temperature-time trajectories: Influence on heat sensitive constituents. Food Research International (2024).
2. Particle structure development during spray drying from a single droplet to pilot-scale perspective. Journal of Food Engineering (2023).
3. Effect of the Addition of Diblock Copolymer Nanoparticles on the Evaporation Kinetics and Final Particle Morphology for Drying Aqueous Aerosol Droplets. Langmuir (2023).
4. High-resolution thermography and modelling allows for improved characterization of drying sessile single droplets. Journal of Food Engineering (2023).
5. Revealing how maltodextrin-containing droplets dry using optical coherence tomography. Food Research International (2022).