A novel freeze-dissolving approach has been devised that offers greater efficiency and sustainability compared to the classic freeze-drying process to make superfine powder or nanoparticles.
In the research published in the journal ACS Sustainable Chemistry & Engineering, sphere-shaped ice particles were formed in an aqueous mixture of NH4H2PO4 or NaHCO3 to produce their respective nanoparticles.
What is the Freeze-Drying Method?
Due to their significant specific areas and strong reactivity, nanomaterials and superfine powders are gaining popularity in fields such as sustainable and environmental applications.
Nanoparticles (NPs) and superfine powders are often produced using freeze-drying techniques. The initial stage in the freeze-drying technique is a cryogenic procedure that freezes target particles or molecules in an aqueous mixture.
In the aqueous mixture, water molecules solidify quickly via the fast-freeze stage, generating a framework of crystallized ice. This step is also referred to as ice templating or freeze-casting. The crystallized ice framework forces the targeted dissolved molecules or components to produce a nanoscale scaffolding architecture, which results in substances with nanoscale or microscale pores.
The freezing stage defines the architecture of the scaffolding and the ice template, as well as the crystal architecture of the targeted substances inside the ice templates or scaffolds, based on the freezing settings.
The second phase is a drying procedure that uses the process of sublimation to separate water as ice templates. The ice melts throughout the drying phase, but the targeted substances, particles, or molecules stay within the ice. From inside the ice, freeze-cast NPs or porous substances with identical architecture and characteristics may be retrieved.
Schematic diagram of experimental setup for the freeze-dissolving method (top) and the freeze-drying method (bottom). © Yu, Q., Wang, Y., Luo, J., & Yang, H. (2022).
Limitations of Freeze-Drying
Due to the cooler temperatures employed in the drying phase, sublimation speeds are sluggish, and batch drying periods for common pharmacological items can take up to multiple days. The production speeds of such batch-based technologies are constrained by poor freeze-drying speeds and extended cycle operation durations.
Some drawbacks may be mitigated by purchasing a bigger freeze-dryer. Unfortunately, it takes much more time to establish perfect vacuum settings, and temperature and pressure are less consistent throughout the container, which could influence output quality. As a result of the cold temperatures and the vacuum arrangement, the drying phase consumes a lot of energy.
How is the Freeze-Dissolving Method Better?
The initial stage in freeze-dissolving is identical to that of freeze-drying, that is, freeze-casting to create ice containing the target components within and build an ice scaffold target architecture.
The ice is then dissolved at a cold temperature, such as a sub-zero temperature in an additional solvent having a low freezing point in the subsequent phase of the freeze-dissolving process. This additional solvent, like ethanol, acts as an antisolvent for the targeted components yet shows miscibility with water.
As a result, the ice scaffold will dissipate fast in the additional solvent, leaving just the targeted components in a solid-state in the mixture, and the architecture of the targeted components produced within the ice will be conserved.
Fire suppression chemicals, baking soda, ammonium dihydrogen phosphate (NH4H2PO4), and sodium bicarbonate (NaHCO3) are water-soluble but do not dissolve in ethanol.
In this work, various quantities of sodium bicarbonate or ammonium dihydrogen phosphate, dissolved in water, were employed to manufacture NPs via the freeze-dissolving technique, which were then evaluated against NPs produced by freeze-drying.
Schematic diagram of the freeze-dissolving and freeze-drying mechanisms for the formation and isolation of NaHCO3 nanoparticles. © Yu, Q., Wang, Y., Luo, J., & Yang, H. (2022).
Important Findings
To extract superfine powder and NPs from ice templates within frozen particles, the proposed freeze-dissolving process offers greater efficiency and sustainability compared to the conventional freeze-drying approach.
Particles of sodium bicarbonate and ammonium dihydrogen phosphate aqueous mixtures were quickly frozen to produce sphere-shaped ice particles, which were then filled with NPs and superfine powder of NaHCO3 or NH4H2PO4.
The frozen components were dispersed in ethanol for 5 minutes at 10 °C using the freeze-dissolving procedure to separate the ice scaffold. The freeze-drying approach, on the other hand, needed 1400 minutes to separate the ice scaffold via the process of sublimation. In identical experimental settings, the dimensions of the end products generated by the freeze-dissolving approach were comparatively small as opposed to those produced by the freeze-drying approach.
The freezing-dissolving approach reported in this study is approximately 100 times quicker and consumes roughly 100 times lesser energy as compared to the freeze-drying approach, without the need for a large facility or a vacuum. As a result, the freeze-dissolving process is likely to be used on an industrial scale with less time, energy, and footprint.
News
Scientists Find a Berry Compound That Helps Muscle Cells Burn Fat
Pterostilbene, a compound found naturally in some foods, affects how skeletal muscles process fats by stabilizing a protein called PPARδ and increasing its signaling activity. Pterostilbene, a natural compound found in blueberries, grapes, and [...]
Two Hidden Forces Help Build the Human Brain Before Birth
Scientists have uncovered two surprising forces that help guide how the human brain forms before birth. Before birth, the human brain is shaped in large part by an unusual class of stem cells known [...]
Researchers Uncover a Hidden Trigger Behind Chronic Inflammation
The findings offer new insights that could help guide the development of future therapies. A protein called human resistin may help flip on one of the immune system’s most powerful inflammatory switches. Researchers at [...]
Scientists Have Uncovered Previously Hidden Microbial Activity on Human Skin
The most abundant microbes on your skin may not be the ones doing most of the work. Human skin supports vast communities of bacteria, fungi, and viruses that can influence its protective barrier, immune [...]
Brazilian Tree Compounds Fight COVID-19 on Multiple Fronts
Scientists found compounds in a Brazilian tree that hit SARS-CoV-2 on multiple fronts, revealing a promising new lead in the search for COVID-19 treatments. Researchers have found that galloylquinic acids extracted from the leaves [...]
Cutting Two Amino Acids Slowed Prostate Cancer in Mice
A newly identified link between amino acid metabolism and cholesterol production may help prostate tumors adapt to hormone therapy. Prostate cancer can find ways around treatments designed to deprive tumors of the hormones they [...]
Largest-Ever Physics Survey Raises New Doubts About Our Model of the Universe
Physicists around the world remain deeply divided on key mysteries of the universe, from dark matter to quantum gravity. The standard cosmological model failed to gain majority support, and no leading theory dominated the [...]
Scientists Just Overturned a 100-Year-Old Belief About Bacteria in the Lungs
New findings raise questions about the role of microbes living in the lungs. More than 35 trillion bacteria live throughout the human body, forming microbiomes in the gut, mouth, lungs, skin, and urogenital tract. [...]
GHCE Concept
From the preface of the book Global Health Care Equivalency in the Age of Nanotechnology, Nanomedicine and Artificial Intelligence, Edited by Frank Boehm: Since the publication of my first book (Nanomedical Device and Systems [...]
Novartis, Ionis drug failure spurs questions
Pelacarsen didn’t protect heart health despite lowering levels of a protein particle, “Lp(a),” in a large clinical trial — a result with important implications for cardiovascular drug research. Dive Brief: An RNA drug from [...]
New injectable treatment helps the brain rebuild after stroke
Biomedical engineers at Duke University have created an injectable biomaterial that may help the brain recover from damage left behind by an ischemic stroke. In experiments with mice, the material transformed the cavity created [...]
Scientists Discover a Hidden “Immune Organ” Inside the Skull
Researchers discovered lymph node-like immune hubs inside skull bone marrow that appear to act as rapid-response centers for the brain. For decades, the brain was thought to operate largely apart from the immune system. [...]
Engineered tRNAs and lipid nanoparticles target nonsense mutation cystic fibrosis
Researchers have developed a potential new approach for treating a form of cystic fibrosis caused by so-called nonsense mutations, combining chemically modified transfer RNAs with lipid nanoparticles designed to deliver the therapy directly to [...]
New pancreatic cancer drug carries a $39,800 monthly list price
A groundbreaking treatment for one of the most common forms of pancreatic cancer has been approved in pill form by the FDA. Revolution Medicines’ oral tablet daraxonrasib, branded as Rasonque, reduced the risk of [...]
Researchers Have Discovered a New Way To Reduce Chronic Nerve Pain
A cancer-linked protein called BRAF may help drive chronic nerve pain, and existing cancer drugs targeting it reduced pain sensitivity in preclinical models. Chronic nerve pain can persist long after an injury and often [...]
Our books now available worldwide!
Online Sellers other than Amazon, Routledge, and IOPP Indigo Global Health Care Equivalency in the Age of Nanotechnology, Nanomedicine and Artifcial Intelligence Global Health Care Equivalency In The Age Of Nanotechnology, Nanomedicine And Artificial [...]
