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This work provides fascinating insights into NIR fluorophore design and methods to effectively alter the photophysical and morphological properties of the nanoaggregates for bio-imaging purposes.

The unique and highly organized three-dimensional structure of metal–organic frameworks (MOFs) formed by self-assembled organic chromophores with metal ions emerges as next-generation luminophores ...

The present study investigates the impact of biomass origin on the properties of biochar and its interaction with different treatment conditions, CO2 adsorption, and regeneration ability. The bioch...

This study represents a successful approach toward employing polycaprolactone-polyamidoamine (PCL-PAMAM) linear dendritic block copolymer (LDBC) nanoparticles as small-molecule carriers in NIR imaging and photothermal therapy. A feasible and robust synthetic strategy was used to synthesize a library of amphiphilic LDBCs with well-controlled hydrophobic-to-hydrophilic weight ratios. Systems with a hydrophobic weight ratio higher than 70% formed nanoparticles in aqueous media, which show hydrodynamic diameters of 51.6 and 96.4 nm. These nanoparticles exhibited loading efficiencies up to 21% for a hydrophobic molecule and 64% for a hydrophilic molecule. Furthermore, successful cellular uptake was observed via trafficking into endosomal and lysosomal compartments with an encapsulated NIR theranostic agent (C3) without inducing cell death. A preliminary photothermal assessment resulted in cell death after treating the cells with encapsulated C3 and exposing them to NIR light. The results of this work confirm the potential of these polymeric materials as promising candidates in theranostic nanomedicine.

A NIR II emissive dye was synthesized by the C–H bond functionalization of 1-methyl-2-phenylindolizine with 3,6-dibromoxanthene. The rhodindolizine (RhIndz) spirolactone product was nonfluorescent;...

The design of visible light absorbing organic dyes as strong photoinduced oxidants is needed for many potential applications in energy production and storage. To access more positive potentials, th...

Shortwave infrared (SWIR) emission has great potential for deep-tissue in vivo biological imaging with high resolution. In this article, the synthesis and characterization of two new xanthene-based RosIndolizine dyes coded PhRosIndz and tolRosIndz is presented. The dyes are characterized via femtosecond transient absorption spectroscopy as well as steady-state absorption and emission spectroscopies. The emission of these dyes is shown in the SWIR region with peak emission at 1097 nm. TolRosIndz was encapsulated with an amphiphilic linear dendritic block co-polymer (LDBC) coded 10-PhPCL-G3 with high uptake yield. Further, cellular toxicity was examined in vitro using HEK (human embryonic kidney) cells where a >90% cell viability was observed at practical concentrations of the encapsulated dye which indicates low toxicity and reasonable biocompatibility.

The present study examined the effect of pyrolysis temperature on the physicochemical properties of biochar, activation process and carbon capture. Two different categories of biochars were synthesized from herbaceous (miscanthus and switchgrass) or agro-industrial (corn stover and sugarcane bagasse) feedstock under four different pyrolysis temperatures- 500, 600, 700 and 800 oC. The synthesized biochars underwent sono-amination activation comprising low-frequency acoustic treatment followed by amine functionalization to prepare adsorbents for CO2 capture. As per the elemental analysis, the elevated pyrolysis temperature resulted in increased %C and %ash contents and reduced %N contents of biochar. The textural analysis exhibited almost 3-times enhancement of micro surface area and pore volume upon increasing the pyrolysis temperature from 500 to 700 oC, though further increase to 800 oC reduced the micro-porosity and the surface area. The intermediate temperatures of 600 and 700 oC revealed the highest interactions with ultrasound-amination, which significantly intensified CO2 adsorption. Accordingly, the CO2 capture capacity of sono-aminated biochars synthesized at 600 and 700 oC were almost 200% greater than that of raw biochars. There were 127-159% and 115-151% increases in adsorption capacity of biochars synthesized at 800 and 500 oC upon ultrasono-amine functionalization. Miscanthus biochar synthesized at 700 oC and treated sono-chemically demonstrated the highest adsorption ability of 2.89 mmol/g at 70 oC and 0.10 atm partial pressure, which is 211% higher than its pristine condition. The superior adsorption capacity of miscanthus (at 700 oC) can be attributed to its large surface area (324.35 m2/g), high carbon content (84%), and low ash content (4.9%), as well as its %N content after sono-amination that was twice that of raw char.

Interfacial properties of cellulose nanocrystals (CNC) and surfactants were studied in high ionic strength (I) brines and correlated to the stability of dodecane/brine Pickering emulsions. Bis-(2-h...

Magnetization facilitates the separation and reuse of adsorbents, but significantly reduces the adsorption capacity. In this study, a double layer magnetized/functionalized biochar composite was synthesized through a hybrid post-pyrolysis magnetization which sustained and even significantly increased the adsorption capacity of microporous carbonaceous biochar (BC). The developed process included i) structural modification of biochar under ultrasound waves, ii) magnetization with magnetite (Fe3O4) nanoparticles, and iii) functionalization with 3-aminopropyltriethoxysilane (TES). Ultrasound irradiation exfoliates and breaks apart the irregular graphite layers of biochar, and creates new, or opens blocked, micropores, thus enhancing the BC’s porosity. For its part, TES stabilizes the magnetic nanoparticles on the biochar surface, while it participates in water decontamination through the strong chelation ability of its amino groups toward metal ions. Scanning electron microscopy demonstrated the stable and uniform distribution of Fe3O4 nanoparticles on the surface of microporous biochar, and Fourier-transform infrared spectroscopy indicated effective surface functionalization. In addition, although magnetization usually reduces the porosity of carbonaceous adsorbents, the ultraviolet–visible spectroscopic analysis showed that double layer magnetic biochar composite exhibited a much greater ability to remove Ni(II) and Pb(II), with 139 % and 38 % higher adsorptions than raw biochar. Almost complete removal of Pb (91 %) was observed by magnetic-BC and the adsorbent could easily be separated using a neodymium magnet. This high performance can be attributed to the synergistic effect of ultrasound activation on increasing the porosity and surface area of biochar along with enhanced chelation imparted by amine functionalization. The developed technique can be used for synthesizing advanced adsorbents for removal of nuclear waste-related metal ions from aqueous environments.

Conventional carbon activation requires heating carbon at a temperature greater than 700 °C for over 3 h, consuming 18,600 kcal/kg of activated biochar. In contrast, the ultrasound treatment method is conducted at ambient condition for a very short duration (∼30 s, which requires about 1135 kcal/kg of activated BC produced. The advanced low-temperature acoustic-based surface modification method not only increases the porosity and surface functionality of raw biochar, but also is economically feasible and environmentally friendly. As a sequel of our previous works, this study aims to investigate the interaction between ultrasonic-structural modification with four different pre-treatments including i) control with no pretreatment, ii) EDC/HBOt, iii) alkali using KOH, iv) acid using HNO3 or H3PO4. The process was then followed by amine functionalization with DEA (diethanolamine) for nickel removal. The results demonstrated that all acoustic-based amine-functionalized biochar samples, without any exception, had more amine- and oxygen-containing functional groups as well as micro porosity, compared to those aminated without acoustic-activation, particularly in samples pretreated with HNO3 and H3PO4. Despite an increase in porosity by ultrasonication, metal leaching from US-only samples and those activated with EDC/HOBt was observed during longer adsorption durations. However, the synergism created by the combined effect of ultrasound and KOH and H3PO4, not only enhanced the adsorption capacity of biochar but also significantly reduced the adsorption duration from 8 to 3 h. The highest nickel adsorptions were observed for ultrasonic-amine samples activated with H3PO4 > HNO3 ∼ KOH, which were far higher (60 %, 49 %, and 46 % more adsorption, without any leaching) than raw or US-biochar, or biochar aminated with EDC/HOBt or without pretreatment.