13 research outputs found
Naphthalene-Based Microporous Polyimides: Adsorption Behavior of CO<sub>2</sub> and Toxic Organic Vapors and Their Separation from Other Gases
Naphthalene was selected as a building
block to prepare three polyimide
networks with different topological structures via one-pot polycondensation
from naphthalene-1,4,5,8-tetracarboxylic dianhydride with tetrakisÂ(4-aminophenyl)Âmethane,
trisÂ(4-aminophenyl)Âamine, and 1,3,5-trisÂ(4-aminophenyl)Âbenzene. The
resultant polymers have moderately large BET surface areas with narrow
pore size distribution at around 6 Ă
. Interestingly, it is found
that they can uptake 90.5 wt % benzene vapor (298 K, 0.8 bar), and
the separation factors of benzene over nitrogen, water, and cyclohexane
are as high as 759.3, 40.3, and 13.8, respectively. The high adsorption
capacity and selectivity of benzene vapor are attributed to the incorporation
of large amount of naphthalene groups in the network since naphthalene
is highly hydrophobic in nature and has strong Ï-electron-delocalization
effect. On the other hand, the CO<sub>2</sub> uptakes in polymers
reach 12.3 wt % (273 K, 1 bar), and the adsorption curves are reversible.
Moreover, the separation factors of CO<sub>2</sub>/N<sub>2</sub> and
CO<sub>2</sub>/CH<sub>4</sub> are 88.6 and 12.9, respectively, superior
to many other microporous organic polymers. The above experimental
results were analyzed and explained with respect to the kinetic diameters,
polarity, critical temperature of the vapors and gases, and the stereoconfiguration
of net nodes, porous characteristics, and hydrophobic/hydrophilic
nature of the pore walls of the microporous polyimides
Facile Synthesis of Fluorinated Microporous Polyaminals for Adsorption of Carbon Dioxide and Selectivities over Nitrogen and Methane
Monoaldehyde compounds, benzaldehyde,
4-methylÂbenzaldehyde,
4-fluoroÂbenzaldehyde, and 4-trifluoroÂmethylÂbenzaldehyde,
were utilized to react with melamine respectively to yield four hyper-cross-linked
microporous polyaminal networks, PAN-P, PAN-MP, PAN-FP, and PAN-FMP,
via a facile âone-stepâ polycondensation without adding
any catalyst. It is found that relative to non-fluorinated polymers
the fluorinated ones show the increased BET specific surface areas
from 615 to 907 m<sup>2</sup> g<sup>â1</sup>. Moreover, the
incorporations of methyl and trifluoromethyl on the phenyl rings can
effectively tailor the pore sizes from 0.9 to 0.6 nm. The polar CâF
bond and nitrogen-rich polyaminal skeleton result in high CO<sub>2</sub> adsorption enthalpies (38.7 kJ mol<sup>â1</sup>) and thereby
raise the CO<sub>2</sub> uptake up to 14.6 wt % (273 K, 1 bar) as
well as large CO<sub>2</sub>/N<sub>2</sub> and CO<sub>2</sub>/CH<sub>4</sub> selectivities of 78.1 and 13.4 by the ideal adsorbed solution
theory, respectively. The facile and scalable preparation method,
low cost, and large CO<sub>2</sub> adsorption and selectivities over
N<sub>2</sub> and CH<sub>4</sub> endow the resultant microporous polyaminals
with promising applications in CO<sub>2</sub>-capture from flue gas
and natural gas
Tetraphenyladamantane-Based Polyaminals for Highly Efficient Captures of CO<sub>2</sub> and Organic Vapors
Tetraphenyladamantane-based polyaminals
with ultrasmall pore, large
specific surface area and abundant CO<sub>2</sub>-philic aminal groups
are successfully synthesized, which exhibit simultaneously high CO<sub>2</sub> adsorption capacity of 17.6 wt % (4.0 mmol g<sup>â1</sup>, 273 K/1.0 bar) and high adsorption selectivities of CO<sub>2</sub>/N<sub>2</sub> (104) and CO<sub>2</sub>/CH<sub>4</sub> (24). Especially,
at the low pressure, e.g., 0.15 bar, the CO<sub>2</sub> uptake at
273 K can reach 8.7 wt % (1.97 mmol g<sup>â1</sup>). The adsorption/selectivity
properties are superior to most of microporous organic polymers (MOPs)
reported in the literature. Besides the outstanding CO<sub>2</sub>-capturing ability, the polymers also possess high uptakes of benzene
and cyclohexane vapors up to 72.6 and 52.7 wt %, respectively. In
addition, the effects of reaction activity and type of amino groups
as well as the size and shape of building blocks on porous architecture
of microporous polyaminals are studied. The disclosed results are
helpful for the deep understanding of pore formation and interconnecting
behavior in MOPs and therefore are of significant importance for the
synthetic control of MOPs for a specific application in gas storage
and capture of organic vapors
Summary statistics of <i>P. olivaceus</i> transcriptome sequencing and assembly.
<p>Summary statistics of <i>P. olivaceus</i> transcriptome sequencing and assembly.</p
Length distribution of the assembled (blue) and the annotated unigenes (red) of <i>P. olivaceus</i>.
<p>Length distribution of the assembled (blue) and the annotated unigenes (red) of <i>P. olivaceus</i>.</p
Gene ontology (GO) annotations of the annotated unigenes.
<p>12,503 unigenes were assigned to three GO categories containing 52 functional subcategories.</p
Immune pathways annotated in the <i>P.olivaceus</i> spleen transcriptome.
<p>Immune pathways annotated in the <i>P.olivaceus</i> spleen transcriptome.</p
Quantitative Real-time PCR (qRTâPCR) validation of the expressed genes in transcriptome sequencing.
<p>IRAK4: interleukin-1 receptor-associated kinase 4; IRF7: interferon regulatory factor 7; INFAR: interferon receptor 1; NFKB1: nuclear factor NF-kappa-B p105 subunit; TRAF6: TNF receptor-associated factor 6; AKT: RAC serine/threonine-protein kinase; IRAK1: interleukin-1 receptor-associated kinase 1; F2: coagulation factorII; TNFA: tumor necrosis factor superfamily. Values are presented as means ± standard deviationïŒn = 5ïŒand the error bars indicate the standard deviation.</p
Venn diagram showing the comparison among <i>P. olivaceus</i> transcriptomic sequences with the known sequences from <i>D. rerio</i> and <i>P. olivaceus</i> EST deposited in the NCBI database.
<p>Venn diagram showing the comparison among <i>P. olivaceus</i> transcriptomic sequences with the known sequences from <i>D. rerio</i> and <i>P. olivaceus</i> EST deposited in the NCBI database.</p