Materials with controlled porosity have found diverse applications in separation, catalysis, energy storage, sensors and actuators, tissue engineering and drug delivery. Multiple methods have been developed to fabricate well-defined porous materials with the pore sizes ranging from nanometers to millimeters.
For example, the introduction of sacrificial templates can impart porosity to the materials encapsulating them after the removal of embedded materials. Alternatively, procedures involving phase separation, direct templating and chemical reaction have demonstrated fabrication of hierarchical porous structures. These methods inherently require multiple steps, and are limited in the attainable complexity of the fabricated structures.
Recent advances in digital fabrication, represented by 3D printing, has enabled fabrication of porous 3D structures consisting of polymeric materials with porosity, yet limited by materials applicable to the process.
For example, solvent-casting 3D printing (SC3DP)--direct 3D printing of polymer inks with in situ evaporation of solvents--has allowed fabrication of 3D porous structures with stringent requirement of rheological properties of the printing ink (e.g. high viscosity and high vapor pressure).
Researchers from the Singapore University of Technology and Design's (SUTD) Soft Fluidics Lab developed a novel 3D printing method to fabricate 3D porous models in one step, which was termed immersion precipitation 3D printing (ip3DP). In the newly developed approach, inks containing polymers were directly printed in a bath of a non-solvent, and the printed ink solidified rapidly via immersion precipitation.
Spontaneous solidification via immersion precipitation generated porosity at micro-to-nano scales. The porosity of the 3D printed objects is easily controlled by the concentrations of polymers and additives, and the types of solvents. A wider selection of solvents permitted a wider range of thermoplastics to be printed. To highlight this capability, fabrications of centimeter-scale models in 13 polymers dissolved in six solvents was demonstrated.
"This work is the first demonstration of three-dimensionally controlled immersion precipitation based on digitally controlled depositions of materials," said lead author of the paper Dr Rahul Karyappa.
The principal investigator, Assistant Professor Michinao Hashimoto stated that "the wide selection of printable materials, and ability to tailor their morphologies and properties, make ip3DP a novel approach for 3D printing to fabricate functional structures."
This work has been published online on July 8, 2019 in Materials Horizons, a leading journal that encourages exceptionally high quality, innovative materials science research. Akihiro Ohno, a research assistant at SUTD also participated in this research project.
Melissa Koh | EurekAlert!
A remote control for neurons
04.06.2020 | College of Engineering, Carnegie Mellon University
Smart textiles made possible by flexible transmission lines
03.06.2020 | Ecole Polytechnique Fédérale de Lausanne
Humans rely dominantly on their eyesight. Losing vision means not being able to read, recognize faces or find objects. Macular degeneration is one of the major...
In meningococci, the RNA-binding protein ProQ plays a major role. Together with RNA molecules, it regulates processes that are important for pathogenic properties of the bacteria.
Meningococci are bacteria that can cause life-threatening meningitis and sepsis. These pathogens use a small protein with a large impact: The RNA-binding...
An analysis of more than 200,000 spiral galaxies has revealed unexpected links between spin directions of galaxies, and the structure formed by these links...
Two prominent X-ray emission lines of highly charged iron have puzzled astrophysicists for decades: their measured and calculated brightness ratios always disagree. This hinders good determinations of plasma temperatures and densities. New, careful high-precision measurements, together with top-level calculations now exclude all hitherto proposed explanations for this discrepancy, and thus deepen the problem.
Hot astrophysical plasmas fill the intergalactic space, and brightly shine in stellar coronae, active galactic nuclei, and supernova remnants. They contain...
In living cells, enzymes drive biochemical metabolic processes enabling reactions to take place efficiently. It is this very ability which allows them to be used as catalysts in biotechnology, for example to create chemical products such as pharmaceutics. Researchers now identified an enzyme that, when illuminated with blue light, becomes catalytically active and initiates a reaction that was previously unknown in enzymatics. The study was published in "Nature Communications".
Enzymes: they are the central drivers for biochemical metabolic processes in every living cell, enabling reactions to take place efficiently. It is this very...
19.05.2020 | Event News
07.04.2020 | Event News
06.04.2020 | Event News
05.06.2020 | Life Sciences
05.06.2020 | Physics and Astronomy
05.06.2020 | Life Sciences