8 research outputs found
<i>N</i>‑Vinylimidazole-Modified Post-Cross-Linked Resin with Pendent Vinyl Groups and Their Adsorption of Phenol from Aqueous Solution
Herein <i>N</i>-vinylimidazole (VIM) was employed as
the polar monomer in the polymerization, and a series of VIM-modified
post-cross-linked resins with vinyl groups were prepared by altering
the initial cross-linking degree and mass percentage of toluene in
the porogens. The results indicate that the initial cross-linking
degree and the porogens have great influence on the porosity and adsorption
performance. The resins with a higher initial cross-linking degree
and a higher mass percentage of toluene in the porogens possess higher
Brunauer–Emmett–Teller surface area and pore volume.
Moreover, the Friedel–Crafts alkylation reaction induces the
greater increased micropore area and micropore volume. HPDV-90%–50%
with the initial cross-linking degree of 90% and using 50% (w/w) toluene
and 50% (w/w) benzyl alcohol (TA) in the porogens has the largest
equilibrium capacity to phenol. The equilibrium data are well characterized
by the Freundlich model, and the isosteric heat of adsorption decreases
dramatically with increasing the fractional loading. The adsorption
can reach equilibrium within 80 min, and the intraparticle diffusion
is the rate-limiting step. HPDV-90%–50% exhibits a dynamic
capacity of 40.3 mg/mL wet resin at an initial concentration of 520
mg/L and a flow rate of 1.6 mL/min, and it can be completely regenerated
with an excellent regeneration property
Hydrogen Bonding of Acylamino-Modified Macroporous Cross-Linked Polystyrene Resins with Phenol
Hydrogen bonding plays an important
role in the adsorption of organic
compounds on polymeric adsorbents. Herein, three acylamino-modified
macroporous cross-linked polystyrene resins, namely, PMVBA, PVBA,
and PVBU, are synthesized and their adsorption of phenol is investigated
in detail from hexane. The results indicate that about 3.70 mmol/g
acylamino groups are uploaded on the resins, the adsorption of these
resins to phenol is efficient, and the equilibrium capacity has an
order of PVBU > PMVBA > PVBA. The isosteric enthalpy of adsorption
is calculated, and it possesses a similar order of PVBU (−63.38
± 9.2 kJ/mol) > PVBA (−55.81 ± 7.8 kJ/mol) >
PMVBA
(−39.87 ± 5.5 kJ/mol) at the zero fractional loading.
Analysis of the adsorption mechanism suggests that hydrogen bonding
is the main driving force for the adsorption, double hydrogen bonding
is involved for phenol adsorption on PVBA and PVBU, and an approximate
hexahydric ring is formed during this process
Synthesis of Triazine-Based Porous Organic Polymers Derived N‑Enriched Porous Carbons for CO<sub>2</sub> Capture
Porous
carbon with both high CO<sub>2</sub> uptake and CO<sub>2</sub>/N<sub>2</sub> selectivity is desired for reducing the cost of carbon
capture. Here, we report the preparation of N-enriched porous carbons
(NPCs) derived from the low-cost triazine-based porous organic polymers
using KOH as the activating agent under N<sub>2</sub>. The results
indicate that the nitrogen content and textural properties of the
NPCs can be effectively adjusted by the polymer precursors and the
carbonization temperature. Impressively, the NPCs have an enriched
N content (5.56–11.33 wt %) and abundant porosity (BET surface
area: 394–1873 m<sup>2</sup>/g, pore volume: 0.27–1.56
cm<sup>3</sup>/g), endowing them with high CO<sub>2</sub> uptake (120–207
mg/g at 273 K and 1.0 bar) and acceptable CO<sub>2</sub>/N<sub>2</sub> selectivity (Henry’s law: 14.3–16.8). In particular,
the ultra micropore volume (<i>d</i> ≤ 0.8 nm) is
proven a key factor for the CO<sub>2</sub> uptake, while both the
ultra micropore volume and N content contribute the CO<sub>2</sub>/N<sub>2</sub> selectivity. Our described work will provide a strategy
to initiate developments of rationally designed porous carbons for
various potential applications
Adsorption of Berberine Hydrochloride, Ligustrazine Hydrochloride, Colchicine, and Matrine Alkaloids on Macroporous Resins
This research aims at identifying
suitable resin adsorbents for
efficient separation and purification of alkaloids from plant materials.
The adsorption properties (equilibrium, kinetics, and column breakthrough)
of four alkaloid model compounds (berberine hydrochloride, ligustrazine
hydrochloride, colchicine, and matrine) on selected macroporous resins
were studied. The adsorption equilibrium capacities and desorption
ratios of the four model compounds on nine different macroporous resins
were measured and compared. It was observed that the resins with a
low polarity and high surface area offered a high adsorption capacity
for all alkaloids. The pseudo-second-order adsorption rate equation
fit well all the kinetic data, and the Langmuir and Freundlich isotherm
equations correlate well the adsorption isotherms on the four resins.
Among the nine resins studied in this work, the HPD300 resin was identified
as the most promising adsorbent for alkaloids separation and purification
because of its excellent adsorption and desorption properties for
all four alkaloid compounds. The adsorption breakthrough experiment
on the HPD300 resin using a mixture solution containing all four model
compounds further confirmed the effective separation of alkaloids
on the HPD300 resin
Controllable Synthesis of Polar Modified Hyper-Cross-Linked Resins and Their Adsorption of 2‑Naphthol and 4‑Hydroxybenzoic Acid from Aqueous Solution
We synthesized a series of polar
hyper-cross-linked resins, and
the porosity and polarity of these resins were effectively tuned by
feeding different amounts of glycidyl methacrylate (GMA). As the feeding
amount of GMA increased, the Brunauer–Emmett–Teller
surface area, pore volume, micropore area, and micropore volume sharply
decreased; the pore size distribution of the resins showed a large
population of pores in the microporous region extending to a higher
part of the mesoporous region, and the O content increased while the
static contact angle lowered. The adsorption experiments indicated
that these resins were efficient for adsorption of 2-naphthol and
4-hydroxybenzoic acid (4-HBA). The adsorption process was very fast,
and the kinetic data for the adsorption of 2-naphthol could be well-fitted
by a pseudo-second-order rate equation, while those for the adsorption
of 4-HBA could be characterized by a pseudo-first-order rate equation
Adsorption of CO<sub>2</sub>, CH<sub>4</sub>, and N<sub>2</sub> on Ordered Mesoporous Carbon: Approach for Greenhouse Gases Capture and Biogas Upgrading
Separation
of CO<sub>2</sub> and N<sub>2</sub> from CH<sub>4</sub> is significantly
important in natural gas upgrading, and capture/removal
of CO<sub>2</sub>, CH<sub>4</sub> from air (N<sub>2</sub>) is essential
to greenhouse gas emission control. Adsorption equilibrium and kinetics
of CO<sub>2</sub>, CH<sub>4</sub>, and N<sub>2</sub> on an ordered
mesoporous carbon (OMC) sample were systematically investigated to
evaluate its capability in the above two applications. The OMC was
synthesized and characterized with TEM, TGA, small-angle XRD, and
nitrogen adsorption/desorption measurements. Pure component adsorption
isotherms of CO<sub>2</sub>, CH<sub>4</sub>, and N<sub>2</sub> were
measured at 278, 298, and 318 K and pressures up to 100 kPa, and correlated
with the Langmuir model. These data were used to estimate the separation
selectivities for CO<sub>2</sub>/CH<sub>4</sub>, CH<sub>4</sub>/N<sub>2</sub>, and CO<sub>2</sub>/N<sub>2</sub> binary mixtures at different
compositions and pressures according to the ideal adsorbed solution
theory (IAST) model. At 278 K and 100 kPa, the predicted selectivities
for equimolar CO<sub>2</sub>/CH<sub>4</sub>, CH<sub>4</sub>/N<sub>2</sub>, and CO<sub>2</sub>/N<sub>2</sub> are 3.4, 3.7, and 12.8,
respectively; and the adsorption capacities for CH<sub>4</sub> and
CO<sub>2</sub> are 1.3 and 3.0 mmol/g, respectively. This is the first
report of a versatile mesoporous material that displays both high
selectivities and large adsorption capacities for separating CO<sub>2</sub>/CH<sub>4</sub>, CH<sub>4</sub>/N<sub>2</sub>, and CO<sub>2</sub>/N<sub>2</sub> mixtures
Engineering MMP‑2 Activated Nanoparticles Carrying B7-H3 Bispecific Antibodies for Ferroptosis-Enhanced Glioblastoma Immunotherapy
Administration of bispecific antibodies (biAbs) in tumor
therapy
is limited by their short half-life and off-target toxicity. Optimized
strategies or targets are needed to overcome these barriers. B7-H3
(CD276), a member of the B7 superfamily, is associated with poor survival
in glioblastoma (GBM) patients. Moreover, a dimer of EGCG (dEGCG)
synthesized in this work enhanced the IFN-γ-induced ferroptosis
of tumor cells in vitro and in vivo. Herein, we prepared recombinant anti-B7-H3×CD3 biAbs and constructed
MMP-2-sensitive S-biAb/dEGCG@NPs to offer a combination treatment
strategy for efficient and systemic GBM elimination. Given their GBM
targeted delivery and tumor microenvironment responsiveness, S-biAb/dEGCG@NPs
displayed enhanced intracranial accumulation, 4.1-, 9.5-, and 12.3-fold
higher than that of biAb/dEGCG@NPs, biAb/dEGCG complexes, and free
biAbs, respectively. Furthermore, 50% of GBM-bearing mice in the S-biAb/dEGCG@NP
group survived longer than 56 days. Overall, S-biAb/dEGCG@NPs can
induce GBM elimination by boosting the ferroptosis effect and enhancing
immune checkpoint blockade (ICB) immunotherapy and may be successful
antibody nanocarriers for enhanced cancer therapy
Oxygen Vacancy-Reinforced Water-Assisted Proton Hopping for Enhanced Catalytic Hydrogenation
Water-assisted
proton hopping (WAPH) has been intensively
investigated
for promoting the performance of metal oxide-supported catalysts for
hydrogenation. However, the effects of the structure of the metal
oxide support on WAPH have received little attention. Herein, we construct
oxygen vacancy-bearing, MoO3–x-supported
Pd nanoparticle catalysts (Pd/MoO3–x-R), where the oxygen vacancies can promote WAPH,
thereby facilitating catalytic hydrogenation. The experimental results
and theoretical calculations show that the oxygen vacancies favor
the adsorption of water, which assists the proton hopping across the
surface of the metal oxide, enhancing the catalytic hydrogenation.
Our finding will provide a potential approach to the design of metal
oxide-supported catalysts for hydrogenation