In this study, carbon dots (CD)-embedded film was successfully fabricated for Fe
3+
sensing via a one-pot process. The carbon dots for Fe
3+
ion detection were synthesized using the cellulose/ionic ...liquid solution for different treatment times. With the increase of the treatment time, the N-doped graphitic structure in the core and the functional groups on the surface were highly developed in the carbon dots. The properties and structures of the carbon dots were characterized using TEM, UV–Vis spectroscopy, XPS, IR, TCSPC, and PL spectroscopy. The carbon dots prepared by 12 h treatment showed a high quantum yield of 28.4%, and the superior stability for long-term storage, UV exposure, ionic strength, and pH change. The carbon dots in the film, as well as in the aqueous dispersion, revealed highly selective detection toward Fe
3+
. The CD-embedded cellulose film can be used as a Fe
3+
indicating film with good reusability, outstanding transparency, and high photostability.
Graphic abstract
The effect of the anion type, in an ionic liquid, on the transition of the crystalline structure when lignocellulose was pretreated in 1-ethyl-3-methylimidazolium acetate (EmimOAC) or ...1-ethyl-3-methylimidazolium chloride (EmimCl) was studied. The influence of the pretreatment on the composition, the molecular structure, and the crystalline structure was observed using Fourier-transform infrared (FT-IR) compositional analysis, thermogravimetric analysis (TGA), rheological behavior, and X-ray diffraction (XRD). Compared to EmimCl, EmimOAC pretreatment substantially decreased the lignin and hemicellulose contents. The pretreatment also significantly changed the entanglement or crosslinking state of polymer chains in the lignocellulose solution. The changes in lignin content and the transformation from cellulose I to II were dependent on the anion type of the ionic liquid. The pretreated samples were recrystallized to cellulose II only in EmimOAC, whereas the samples pretreated with EmimCl had both cellulose I and II structures present at the same time.
•Two types of ionic liquids were applied to lignocellulosic biomass pretreatment.•Different ionic liquids significantly influenced the characteristics of biomass.•The removal efficiency of non-cellulosic components depended on type of ionic liquid and temperature.•Well-dissolved biomass was more hydrolyzed than heterogeneous dissolution.•Improvement of molecular mobility dramatically changed the crystalline structure.
Metal-free photocatalyst was synthesized by attaching carbon dots (CDs) to cellulose nanofibers (CNFs) via simple
in-situ
synthesis. The graphitic core and functional groups of CD on CNF was ...controlled along the precursor concentration, while the fibrous structure of CNF was intact. The optical property of the samples was profoundly analyzed focusing on the electron recombination pathway. It revealed that the excited electrons in the CD transferred to the CNF and delayed the radiative recombination. The electron–hole pairs were efficiently separated in the composite where abundant amide group and sulfide bonding existed. The CDs on the CNF surface improved the morphological stability of CNF under UV irradiation as well. As a result, the composite showed superior photocatalytic performance to degrade 98% of MB molecules within 25 min. The aerogel synthesized from CDCNF had good re-usability without sacrificing its photocatalytic effect. The synthesized CDCNF composites showed superior possibility for applying cellulose nanofiber to sustainable metal-free photocatalyst.
Graphic abstract
In this study, cellulose flexible film was used as a supporting substrate for the development of an eco-friendly graphene gas sensor. The flexible cellulose substrate was fabricated by the method ...reported in the previous study. Graphene was grown on Cu foil using a conventional CVD method and directly transferred onto the cellulose substrate via a wet-transfer method. The results of conductivity, Raman spectroscopy, and SEM images confirmed that graphene was well-transferred onto the cellulose substrate without noticeable cracks. The performance of graphene gas sensors was measured by monitoring the current change according to the periodic injection of NO
2
target and N
2
purging gases. The graphene gas sensor built on cellulose film exhibited superior sensing performance compared to graphene on SiO
2
, mainly due to the functional groups in cellulose film. In addition, the incorporation of halloysite nanotube into cellulose film enhanced the sensitivity of the graphene sensor much more because the surface area of the transferred graphene became larger. This study demonstrates that the highly sensitive graphene gas sensor could be fabricated by the use of ecofriendly cellulose film as a supporting substrate.
This research focused on the preparation of carbon dots (CDs) using cellulose hydrolysis in ionic liquid (IL) at a low temperature of 65 °C without additional treatments. The morphologies of the CDs ...were observed by TEM. The chemical structures and the optical properties were characterized by XPS, FT-IR, UV-vis and PL spectroscopies. As the cellulose was incubated longer in the IL, the size of the CDs was reduced. Besides, the core of the CD was simultaneously nitrogen-doped more with graphitic N, resulting in the increase of the quantum yield up to ∼33 %. For the easier application of the CD in solid state, the CD embedded cellulose film was simply prepared via the one-pot dissolution. The prepared cellulose film showed excellent photoluminescence behaviors as well as the superior transparency of over 97 % in the visible light region.
In this study, three different saccharides (glucose, β-cyclodextrin, and kraft pulp) were hydrothermally carbonized for the synthesis of hydrochar with excellent adsorption capacity, and their ...adsorption behaviors were studied. Glucose and β-cyclodextrin were successfully converted into hydrochars, whereas kraft pulp was not. This study on the morphology and the chemical structure of the hydrochars revealed that the structures of the hydrochars were significantly influenced by the precursor type. The macropore and negatively charged surface of the glucose-based hydrochar were highly beneficial for the organic pollutant adsorption. Methylene blue was adsorbed monolayerly on the hydrochar surfaces via chemisorption. The macropore contributed the intra-particular diffusion of methylene blue, which improved the adsorption capacity of the hydrochar. The glucose-based hydrochar showed remarkable adsorption capacity and could be reused four times.
In this study, the physical states of cellulose in 1-allyl-3-methylimidazolium chloride (AmimCl) were analyzed via rheological observations under three different conditions: namely, steady state, ...small amplitude oscillatory shear, and large amplitude oscillatory shear conditions. The physical state of the solution changed from an isotropic phase to a gel structure via a liquid crystalline (LC) phase as the concentration increased. The rheological analysis showed that the 16 wt% solution was physically gelled in the anisotropic phase. This instantaneous gelation at the LC phase markedly enhanced the mechanical performance of the film obtained from the solution. This study provides a fundamental strategy for significant improvement in the mechanical properties of cellulose fibers or films.
Graphic abstract
Psoriasis is a chronic inflammatory skin disease characterized by the rapid abnormal growth of skin cells in the epidermis, driven by an overactive immune system. Consequently, a complex interplay ...among epidermal cells, immune cells, and sensory neurons contributes to the development and progression of psoriasis. In these cellular contexts, various ion channels, such as acetylcholine receptors, TRP channels, Ca
release-activated channels, chloride channels, and potassium channels, each serve specific functions to maintain the homeostasis of the skin. The dysregulation of ion channels plays a major role in the pathophysiology of psoriasis, affecting various aspects of epidermal cells, immune responses, and sensory neuron signaling. Impaired function of ion channels can lead to altered calcium signaling, inflammation, proliferation, and sensory signaling, all of which are central features of psoriasis. This overview summarizes the pathophysiological roles of ion channels in epidermal cells, immune cells, and sensory neurons during early and late psoriatic processes, thereby contributing to a deeper understanding of ion channel involvement in the interplay of psoriasis and making a crucial advance toward more precise and personalized approaches for psoriasis treatment.
In this study, carbon dot (CD) was
in-situ
synthesized on cellulose nanofiber (CNF) surface by simple one-step hydrothermal carbonization. Based on the analyses of chemical structure and ...photoluminescence characteristics, we changed the electron pathway of carbon dot by controlling the CNF concentration in the composite. The electronic stabilization of CNF was observed in the composites from low CNF concentrations. Meanwhile, with high CNF concentrations, electrons were barely transferred to CNFs but recombined radiatively. Aggregation-induced blue-shifted emission occurred in the solid-state composite films without significant changes in the electron relaxation pathways. This study provides valuable insights into the electron relaxation pathway of the fabricated composite, which may be helpful in the design and economical fabrication of CD-based advanced optical devices.
Lipids from Chlorella vulgaris were successfully extracted using an ionic liquid, BmimMeSO₄. BmimMeSO₄ dissolved C. vulgaris, leaving the lipids insoluble. The undissolved lipids could easily be ...recovered due to the lower density of the lipid phase. Furthermore, ultrasound irradiation highly enhanced the extraction rate and yield with BmimMeSO₄. The total amounts of lipid extracted from C. vulgaris by the Soxhlet method and the Bligh and Dyer's method were 21 and 29 mg/g dry cell weight (DCW), respectively, whereas it was 47 mg/g DCW with BmimMeSO₄. Additionally, the amount of lipid extracted using BmimMeSO₄ was 1.6 times greater with ultrasound irradiation. The rate of extraction of lipids from C. vulgaris with BmimMeSO₄ was also 2.7 times greater with ultrasound irradiation. The fatty acid profiles of the lipids extracted using BmimMeSO₄ were very similar to those of the lipids obtained by Bligh and Dyer's method.
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