Construction of N-Rich Aminal-Linked Porous Organic Polymers for Outstanding Precombustion CO2 Capture and H2 Purification: A Combined Experimental and Theoretical Study.

A large number of scientific investigations are needed for developing a sustainable solid sorbent material for precombustion CO2 capture in the integrated gasification combined cycle (IGCC) that is accountable for the industrial coproduction of hydrogen and electricity. Keeping in mind the industrially relevant conditions (high pressure, high temperature, and humidity) as well as good CO2/H2 selectivity, we explored a series of sorbent materials. An all-rounder player in this game is the porous organic polymers (POPs) that are thermally and chemically stable, easily scalable, and precisely tunable. In the present investigation, we successfully synthesized two nitrogen-rich POPs by extended Schiff-base condensation reactions. Among these two porous polymers, TBAL-POP-2 exhibits high CO2 uptake capacity at 30 bar pressure (57.2, 18.7, and 15.9 mmol g-1 at 273, 298, and 313 K temperatures, respectively). CO2/H2 selectivities of TBAL-POP-1 and 2 at 25 °C are 434.35 and 477.93, respectively. On the other hand, at 313 K the CO2/H2 selectivities of TBAL-POP-1 and 2 are 296.92 and 421.58, respectively. Another important feature to win the race in the search of good sorbents is CO2 capture capacity at room temperature, which is very high for TBAL-POP-2 (15.61 mmol g-1 at 298 K for 30 to 1 bar pressure swing). High BET surface area and good mesopore volume along with a large nitrogen content in the framework make TBAL-POP-2 an excellent sorbent material for precombustion CO2 capture and H2 purification.

Recent Developments on the Catalytic and Biosensing Applications of Porous Nanomaterials.

Nanoscopic materials have demonstrated a versatile role in almost every emerging field of research. Nanomaterials have come to be one of the most important fields of advanced research today due to its controllable particle size in the nanoscale range, capacity to adopt diverse forms and morphologies, high surface area, and involvement of transition and non-transition metals. With the introduction of porosity, nanomaterials have become a more promising candidate than their bulk counterparts in catalysis, biomedicine, drug delivery, and other areas. This review intends to compile a self-contained set of papers related to new synthesis methods and versatile applications of porous nanomaterials that can give a realistic picture of current state-of-the-art research, especially for catalysis and sensor area. Especially, we cover various surface functionalization strategies by improving accessibility and mass transfer limitation of catalytic applications for wide variety of materials, including organic and inorganic materials (metals/metal oxides) with covalent porous organic (COFs) and inorganic (silica/carbon) frameworks, constituting solid backgrounds on porous materials.

When Task is Huge but Time is Short! An Interesting Case of Stroke Thrombolysis.

A 64-year-old gentleman, diabetic, and smoker attended the emergency room (ER) with acute stroke. He had expressive aphasia with right upper limb weakness. His blood pressure was extremely high, and he presented in the final half an hour of the permissible window period for thrombolysis. Bringing down his blood pressure to make him eligible for the procedure within the available time was a real challenge for us. Fortunately, we succeeded in our attempt and he gradually improved. Truly, the maximum blood pressure allowable in his case to make him still eligible for thrombolysis was not clear to us. He had an explainable intracranial arterial stenosis and was probably auto-regulating during his acute presentation. Hence, we could have been more lenient in bringing down his blood pressure and thrombolyzed him earlier. A modified guideline will help us to handle these special situations more confidently and allow more patients to get the benefit of thrombolysis.

Role of polymer template in crystal structure and photoactivity of Cu-TiO2 heterojunction nanostructures towards environmental remediation.

Exploring porous heterojunction nanomaterials as a photocatalyst for water depollution strategies towards environmental restoration is exceedingly difficult in the perspective of sustainable chemistry. Herein, we first report a porous Cu-TiO2 (TC40) heterojunction by using microphase separation of a novel penta-block copolymer (PLGA-PEO-PPO-PEO-PLGA) as a template through an evaporation induced self-assembly (EISA) method having nanorod-like particle shape. Furthermore, two types of photocatalyst were made with or without polymer template to clarify the function of that template precursor on the surface and morphology, as well as which variables are the most critical for a photocatalyst. TC40 heterojunction nanomaterial displayed higher BET surface area along with lower band gap value viz.2.98 eV compared to the other and these features make it a robust photocatalyst for wastewater treatment. In order to improve water quality, we have carried out experiments on the photodegradation of methyl orange (MO), highly toxic pollutants that cause health hazards and bioaccumulate in the environment. Our catalyst, TC40 exhibits the 100% photocatalytic efficiency towards MO dye degradation in 40 and 360 min at a rate constant of 0.104 ± 0.007 min-1 and 0.440 ± 0.03 h-1 under UV + Vis and visible light irradiation, respectively.

Understanding the mechanism of the energy transfer process from non-plasmonic fluorescence bimetallic nanoparticles to plasmonic gold nanoparticles.

Understanding the fundamentals behind the photophysical response of a fluorescing species in the vicinity of plasmonic nanoparticles is of great interest due to the importance of this event in various applications. The present work has been carried out to throw light on how plasmonic nanoparticles electronically interact with non-plasmonic nanoparticles. Specifically, in this work, the excitation energy transfer (EET) from fluorescence bimetallic silver capped gold (F-AgAu) to gold nanoparticles (AuNPs) and how this process can be modulated by cetyltrimethylammonium bromide (CTAB) have been investigated at both ensemble average and single particle levels. Steady-state and time-resolved fluorescence studies have revealed that the fluorescence intensity and lifetime of F-AgAu in the presence of AuNPs are significantly quenched. Cyclic voltammetry (CV) and polarity-dependent studies have ruled out the possibility of an electron transfer mechanism. The increased non-radiative decay rate has substantiated that the photoluminescence quenching is due to excitation energy transfer from F-AgAu to AuNPs. Interestingly, investigations have revealed that the energy transfer efficiency is reduced from 87% to 28% in the presence of CTAB due to the formation of a CTAB bilayer over AuNPs. Analysis of the data by conventional EET, nano surface energy transfer (NSET), and stretched exponential models have firmly established that the EET process follows a 1/d4 distance dependence (NSET) rather than conventional 1/d6 distance dependence as predicted with the Förster resonance energy transfer model. Additionally, single particle level measurements through fluorescence lifetime imaging microscopy (FLIM) studies have clearly demonstrated that the surfactant (CTAB) can play an important role in controlling the EET process from non-plasmonic to plasmonic nanoparticles. The outcome of the present EET between two different classes of nanoparticles is expected to be useful in developing nanoscale systems for various optoelectronic applications.

Computational assessment of growth of connective tissues around textured hip stem subjected to daily activities after THA.

Longer-term stability of uncemented femoral stem depends on ossification at bone-implant interface. Although attempts have been made to assess the amount of bone growth using finite element (FE) analysis in combination with a mechanoregulatory algorithm, there has been little research on tissue differentiation patterns on hip stems with proximal macro-textures. The primary goal of this investigation is to qualitatively compare the formation of connective tissues around a femoral implant with/without macro-textures on its proximal surfaces. This study also predicts formation of different tissue phenotypes and their spatio-temporal distribution around a macro-textured femoral stem under routine activities. Results from the study show that non-textured implants (80 to 94%) encourage fibroplasia compared to that in textured implants (71 to 85.38%) under similar routine activity, which might trigger aseptic loosening of implant. Formation of bone was more on medio-lateral sides and towards proximal regions of Gruen zones 2 and 6, which was found to be in line with clinical observations. Fibroplasia was higher under stair climbing (85 to 91%) compared to that under normal walking (71 to 85.38%). This study suggests that stair climbing, although falls under recommended activity, might be detrimental to patient compared to normal walking in the initial rehabilitation period.