Gene/Protein
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Enzyme
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Pivot Concepts:
Gene/Protein
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Drug
Enzyme
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Target Concepts:
Gene/Protein
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Enzyme
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Query: UMLS:C0267964 (
PAA
)
2,561
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Calcium carbonate
was surface treated by acrylic acid monomer, its polymerization with varied mean molecular weight and PS/
PAA
copolymer. Coating efficiencies for these four series of surface-treated calcium carbonate were investigated. They differ from each other in many aspects. We hypothesize that the treating molecules bond to and align on the particle surface in different ways before and after monolayer coverage was reached. NIR spectra of surface-treated samples studied not only reflected the amount of bonded treating agents by means of the value of absorbance, but also gave rich structural information of surface layer. This gave us a powerful means to investigate the interface of particle surface.
...
PMID:The mechanical and NIR studies on ultrafine calcium carbonate treated by four surface modifiers. 1467 May 11
Calcium carbonate
(CaCO
3
) is one of the most abundant biominerals that is prevalent in rocks and often used as a structural material in marine animals. Many of these natural CaCO
3
-based materials display excellent mechanical properties that are difficult to reproduce by man-made counterparts. This difficulty arises from the incomplete understanding of the influence of processing conditions on the structure and composition of CaCO
3
. To gain a better understanding of the evolution of the structure and composition of amorphous CaCO
3
(ACC) particles during early stages, we introduce a new, organic solvent-free method that quenches this process with a high temporal resolution. We produce ACC particles inside small airborne drops that are formed with a microfluidic spray-dryer. These drops dry within 100 ms to 10 s and thereby arrest the formation of CaCO
3
particles on that time scale. Using the microfluidic spray-dryer, we demonstrate that the amount of mobile water contained in ACC particles increases with increasing formation time and hence with increasing particle size. As a result of the higher concentration of mobile water, larger particles are less stable against temperature-induced solid-state crystallization and electron beam-induced decomposition than smaller counterparts. The amount of mobile water contained in ACC can be substantially reduced, and hence their kinetic stability against solid-state transformations increased, if certain organic additives, such as poly(acrylic acid) (
PAA
), are incorporated. These insights might open up new opportunities to fabricate biomimetic CaCO
3
-based materials with tunable structures and hence with properties that can be adapted to the needs of specific applications.
...
PMID:Amorphous CaCO
3
: Influence of the Formation Time on Its Degree of Hydration and Stability. 3026 27
