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A designed type-II heterojunction photocatalyst, NiSe2/Cd0.5Zn0.5S (NiSe2/CZS), was successfully synthesized and it exhibits outstanding photocatalytic hydrogen evolution performance. The optimal loading amount of NiSe2 on Cd0.5Zn0.5S is 13 wt %, and the corresponding hydrogen production rate is approximately 121.01 mmol g−1 h−1 under visible light. The heterojunction structure between Cd0.5Zn0.5S and NiSe2 promoted the separation of photogenerated electron-hole pairs, effectively suppressed the photogenerated carrier recombination and endowed the material with excellent interfacial charge transfer properties, thus improving the photocatalytic performance.

It is difficult to recycle photocatalysts for water purification when they are in aqueous suspension. Cellulose aerogels with porous structure and biodegradability are promising carriers for photocatalysts that can be used to solve many environmental problems. In this study, a 3D recyclable g-C3N4@cellulose aerogel for photocatalytic degradation of pollutants was synthesized using a facile chemical cross-linking method. g-C3N4@cellulose aerogel (30% loading) exhibited excellent photocatalytic activity up to 99.0% degradation. In addition, the g-C3N4@cellulose aerogel exhibited high recyclability and structural stability while the photocatalytic efficiency is not significantly reduced in cycling tests. The photocatalyst was optimized using high temperature calcination, resulting in 95.35 m2 g−1 actual surface determined from Brunner–Emmet–Teller measurements. Therefore, aggregation of the photocatalyst can be avoided by the cellulose aerogel support whilst the photocatalytic property remained as efficient as its powder form. Such composites may become attractive material for practical applications.

Ni/porous g-C3N4 was prepared by high temperature thermal polymerization process using carbon dots as soft template and photodeposition. With nickel nanoparticles supported as co-catalyst, the hydrogen evolution reaction (HER) activity of the photocatalyst has been significantly enhanced under visible light, which is up to 1273.58 μmol g−1 h−1, superior to pristine g-C3N4 (4.12 μmol g−1 h−1). This is attributed to the inhibited recombination of photogenerated electron-hole pairs and the much better electron transport efficiency. The formed porous structure of carbon nitride could facilitate light utilization and together with nickel nanoparticles, better charge separation can be realized which are proved by the photoluminescence, time-resolved photoluminescence spectra, transient photocurrent measurements and electrochemical impendence spectroscopy. This work provides a useful route to obtain less expensive and efficient photocatalyst containing no noble metals for hydrogen production.

Massive hemorrhage is a frequent cause of human death in the operating room and other emergency situations. Therefore, effective hemostatic wound dressings are essential to save lives. Here we show that, calcium functioned carboxymethylated cotton fabric (MCF-Ca) conveniently prepared by carboxymethylation of cotton fabrics followed by treatment with calcium chloride solution could serve as an effective hemostatic wound dressing. The calcium content of MCF-Ca was determined as 18.11 ± 0.44 mg/g, and the calcium ions were released into a saline solution, a process that reached near-equilibrium within about 2 min. The biocompatible MCF-Ca promoted hemostasis via forming complexes with blood cells, and it showed lower blood clotting index as well as shorter blood clotting time comparing with unmodified CF in vitro. In addition, MCF-Ca exhibited better hemostatic efficiency than CF in vivo, resulting in much shorter hemostasis time and less blood loss in rat liver injury model and femoral artery animal model. In conclusion, MCF-Ca shows good potential to be used as wound dressing for patients with uncontrolled or massive hemorrhage.

Multifunctional cotton fabric with adjustable color was simply fabricated by anchoring solid solution BiOBrxI1−x nanosheets on the surface of carboxymethylated cotton fabric for self-cleaning, UV protection, and near infrared reflection. The structure and morphology of prepared multifunctional cotton fabrics (BiOBrxI1−x-CCF (0 ≤ x ≤ 1)) were characterized by X-ray powder diffraction and scanning electron microscopy. Color, self-cleaning, UV protection, near infrared reflection, and acid and alkali resistance of these multifunctional cotton fabrics were systematically studied. With the increase of iodine content, the BiOBrxI1−x nanosheets with an average thickness of 40–50 nm and a size of 1–2 μm in the other two dimensions loaded on the cotton fabrics can extend the absorption edge of BiOBrxI1−x-CCF (0 ≤ x ≤ 1) from 430 nm to 630 nm, giving cotton fabric color and excellent UV protection property. Interlaced solid solution nanosheets on cotton fabric surface give BiOBrxI1−x-CCF hydrophobicity (contact angle: 139°–143°) and ability to photodegrade stain under the visible light irradiation. The near infrared reflectance of BiOBrxI1−x-CCF (0 ≤ x ≤ 1) is higher than that of the raw cotton, which gives it infrared reflection thermal isolation. BiOBrxI1−x-CCF (0 ≤ x ≤ 1) has a certain acid and alkali resistance in solution (pH 2.3–11.2). Thus, BiOBrxI1−x-CCF has great potential to be used as multifunctional fabric in self-cleaning and outdoor protection.

Achieving effective hemostasis is significant to ensure the survival of the people with acute massive bleeding in the battlefield or daily life in pre-hospital care. In this work, modified cotton fabric with asymmetric wettability (Janus) was prepared using a fast and simple spray-coating strategy, where, one side of the fabric was sprayed with carboxymethyl chitosan solution to achieve hydrophilicity (0°) while the other side with hydrophobicity (152°) was built using paraffin. The hydrophilic surface could provide blood absorption and promote hemostasis, while the hydrophobic surface prevented the excessive blood absorption. The hemostatic efficiency of fabrics was tested in vitro and in vivo. Here, the carboxymethyl chitosan coated carboxymethylated cotton (CS-MCF) and Janus showed better hemostatic capacity than the cotton fabric (CF) in vitro with the lower blood clotting index. Furthermore, the Janus had better hemostatic performance than CF in rat liver animal model, and prolonged the survival time of the rats in carotid artery animal model. Therefore, Janus, with superior hemostatic efficiency over the cotton fabric, has a bright application prospect as hemostatic wound dressing.

A multi-responsive chromic textile was conveniently fabricated by screen-printing with a covalent organic polymer of viologen (COP2+) on the surface of cotton fabric, which was endowed with ammonia sensing, photochromic and thermochromic capabilities. The COP2+ coated fabric (CCF) were characterized by Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy. The coating treatment endowed the fabric with fast response to ammonia gas, ultraviolet light and heat without compromising its breathability, flexibility, and comfortability. The color of CCF turned from yellow to green instantly when exposed to ammonia gas and quickly returned yellow when removed from the stimulus. The reversible color transition process can also be induced by UV light (exposure for 10 s) or heat (110 °C) and is cyclable. This durable multi-responsive textile has great potential to be used as flexible sensor for environmental monitoring.

High-performance textile electrodes are promising electronic components that can meet the growing demand for wearable applications. In this study, woven and knitted fabrics, such as cotton, wool, silk, and polyester, were transformed into metal-free conducting electrodes by an improved in situ polymerization method. The method improved the conjugate length of the polypyrrole (PPy) molecule and doping levels and provided a thin and dense conductive polymer coating on the fabric surface. The sheet resistance of the resulting textile electrodes was less than 10 Ω sq−1. The PPy-coated textile electrodes contained superior electrical conductivity, without compromising the textiles breathability, flexibility, and comfortability. The tensile strength and wet crease recovery angles of the fabric were significantly improved after the incorporation of PPy onto its surface. The textile electrodes were more stable to organic solvent washing than to water washing. Their conductivities were nearly unchanged after washing in dichloromethane with 20 laundering cycles. The high conductivity of the PPy coating provided textile electrodes with good electrical heating properties. The PPy-coated textile electrodes (knitted cotton) demonstrated the highest specific capacitance of 4848 mF cm−2 at 1 mA cm−2, good cycling stability, and excellent flexibility. This study provided a simple and effective method to transform a commercial textile into wearable electronic components.

The Biginelli multicomponent reaction has been used as an effective and model method to efficiently prepare a library of cellulose derivatives based on cellulose acetoacetate (CAA). Various cellulose derivatives containing 3, 4-dihydropyrimidin-2(1 H)-ones (DHPMs) with different functional groups (carboxyl, methoxyl, and nitro) are synthesized. The entire reaction process is followed using FT-IR, 1H NMR. The results demonstrate that more than 80% of the acetoacetyl groups are converted within four hours. Additionally, all the cellulose derivatives are confirmed to have favorable thermostability and good solubility in selected solvents. Furthermore, polymers (in this case, poly (ethylene glycol) monomethyl ether (mPEG)) can also be anchored to the cellulose backbone via this facile modular approach. Therefore, the Biginelli multicomponent reaction offers a straightforward method for diverse and large-scale cellulose derivatization. These results are expected to prompt broader study of this multicomponent reaction in interdisciplinary fields.

A multifunctional cotton fabric was prepared by immobilizing bismuth oxyiodide (BiOI) nanosheets on the surface of cotton treated to briefly dissolve surface molecules with upon the low-temperature addition of NaOH and urea (cotton micro-dissolution). Immobilization was accomplished by successive adsorption and reaction (SILAR) at the temperature (~ 25 °C). The morphology, structural characteristics, photodegradation ability for organic pollutants, UV shielding, and self-cleaning of the treated fabric were studied. The growth rate and uniformity of the BiOI nanosheets were compared between the treated fabrics and the untreated fabrics. The absorption wavelength of the cotton fabric with BiOI nanosheets was extended to the visible light (~ 630 nm) region. Under visible light irradiation, cotton fabric containing BiOI nanosheets (BiOI > 8.4 wt%) showed remarkable photocatalytic ability for degrading rhodamine B (RhB) with a degradation rate of 99% (C0 = 20 mg/L) and 95% after the first and sixth cycle, respectively. The ultraviolet protection factor (UPF) of cotton fabric with BiOI nanosheets was > 50, and its transmittance of ultraviolet A (T(UVA)) was

Herein, a PVA (polyvinyl alcohol)-based multi-responsive hydrogel was prepared by introducing the dynamic and reversible supramolecular complexation between polyvinyl alcohol acetoacetate (PVAA) and Fe3+ ions within 20 s at room temperature. PVAA-Fe hydrogels could be achieved by the simple mixing process of a PVAA aqueous solution with FeCl3 aqueous solution. The soluble PVAA was synthesized by the reaction of PVA with tert-butyl acetoacetate (t-BAA) via transesterification in dimethyl sulfoxide (DMSO). The chemical structure of PVAA was systematically characterized by FT-IR and 1H NMR spectroscopy. The resulting hydrogel showed excellent self-healing behavior without other external stimuli. It was also demonstrated that the PVAA-Fe hydrogel exhibited multi-responsive properties, such as responsiveness to pH, redox, light irradiation and temperature. In addition, the presence of Fe3+ ions and Cl- ions in the gel imparted the PVAA-Fe hydrogel with favorable conductivity. Therefore, the strategy for the facile preparation of the hydrogel in this work could provide a benign and versatile method for achieving multi-functional soft materials for various applications such as smart devices, logic gates, and sensors.

Environmental-friendly cellulose-derived sponges were employed as porous templates to achieve uniform Ag deposition via a facile and economical electroless plating method. SEM and BET results confirmed an Ag layer was deposited on cellulose composite sponges without damaging the porous structure. XPS and XRD analysis demonstrated substantial interactions between porous substrates and Ag particles. When utilized as electromagnetic interference (EMI) shielding materials, a 3.2 mm thick silver-plated sponge exhibited a total shielding effectiveness (SEtotal) value of as high as 120.85 dB in the frequency range of 10–1500 MHz when the plating time was 120 min. Moreover, the conductive sponges displayed absorption-dominant mechanism to alleviate secondary radiation, making them promising candidates as high EMI shielding materials. Keywords: Cellulose-derived sponges, Electroless Ag plating, Electromagnetic interference shielding

This work aims to develop a facile two-step method for the fabrication of superamphiphobic and chemical repellent aramid fabrics. The aramid fabrics were coated with a formula consisting of waterborne polyurethane, poly(vinylidene fluoride-co-hexafluoropropylene) and fluoroalkyl silane via both a blade-coating process and an immersion technique. The wettability, surface morphology, thermal stability, chemical composition and chemical protective behaviors of the aramid fabrics were characterized. The coated fabrics showed contact angles of 157 ± 4° and 140 ± 2° for water and sunflower seed oil, respectively. No penetration was observed in coated fabrics stained with H2SO4, NaOH, and N,N-dimethylformamide for up to 150 min. The excellent repellent properties were retained after 10 washing cycles and 200 crocking cycles. Additionally, the coated fabrics showed superb restorable superamphiphobicity, demonstrating good potential to be used for chemical protective clothing.

Covalent grafting of gentamicin to nanocellulose-based sponge was realized for the first time. The named sponge was prepared by initially multi-crosslinking among cellulose nanofibers (CNF), cellulose acetoacetate (CAA) and 3-aminopropyl(triethoxy)silane (APTES) followed by surface modification with gentamicin via the formation of enamine bond. The structure and mechanical performances of the obtained gentamicin-functionalized CNF sponge were characterized with FT-IR, XPS, EDX, SEM, Nitrogen adsorption-desorption measurement, and compressive test. Its antibacterial activity against E. coli and S. aureus was evaluated using disc diffusion and colony forming units (CFU) count methods. The results showed that gentamicin was successfully grafted on the surface of CNF sponges without significant change in morphology and slight improvement in mechanical performance. The superior lightness of the sponge (0.0174 g cm−3) was demonstrated by showing the sponge could be supported by a flower branch without crushing it. Gentamicin-functionalized CNF sponges showed excellent antibacterial performance against E. coli and S. aureus, with bactericidal rates of over 99.9%.

A simple and convenient method for preparing a porous bio-absorbent for treating reactive dyeing effluents was developed. Chitosan adsorbent reinforced with citric acid modified β-cyclodextrin (CA-CD) was prepared via room temperature amidation followed by freeze-drying. Using reactive blue 49 as the model adsorbate, optimum adsorption (up to 500 mg g−1) was achieved with the adsorbent containing 20 wt% CA-CD. The adsorption process was pH-adjustable, so that more efficient dye removal could be achieved by decreasing the pH and regeneration was possible vice versa. Salts and surfactants commonly used in reactive dyeing were found to have moderate negative influence on the adsorption efficiency. The adsorbent was also demonstrated to be generally effective for common reactive dyes including C.I. Reactive Blue 49, Reactive Yellow 176, Reactive Blue 14, Reactive Black 5, and Reactive Red 141, which varied in size and structure. The removal rate of C.I. Reactive Blue 49 was almost 80% even after six adsorption-desorption cycles, confirming the reusability of the adsorbent. Owing to the use of simple and mild preparation conditions, and bio-based chemicals, we believe that this work provides a foundation for the development of environment friendly bio-absorbents for the treatment of reactive dyeing effluents.

The effect of the degree of substitution (DS) on the aqueous solubility of cellulose acetoacetates (CAA) was investigated by molecular dynamics simulations and density functional theory calculations. Using average non-covalent interaction and the electrostatic potential analyses done on cellobiose as the model, it was showed both polar and non-polar areas of the system increased as the more hydroxyls were replaced by acetoacetate groups. Analyses of the solvation free energies of a celludecose (glucan containing 10 monosaccharide sugar units) at constant pressure and temperature showed the polar solvation free energies and the number of decose-water hydrogen bonds increased as DS was varied from 0.3 to 0.8, which contributes to higher solubility in water. When the DS of CAA increased from 0.8 to 1.5, it became insoluble again because the plateaued increase in solvation free energy could no longer compensate for the decreasing CAA-water hydrogen bonding interactions. The growing van der Waals interactions among CAA molecules as the molecule grows bigger with each attached AA group also contributes to the decreasing water solubility.

Waterborne bio-based polymer pigments are promising environmentally friendly coloring materials. In this work, novel colored cellulose suspensions applicable for coloring, labelling and anti-counterfeiting were prepared from waste cotton fabrics. It was demonstrated that cellulose regenerated from a phosphoric acid solution of waste cotton fabrics could be conveniently colored by reacting with reactive dyes. The high specific surface area of the regenerated cellulose (RC) allowed for high color build-up of up to 210 mg/g dye fixation and K/S value of up to 31. The resulting colored regenerated cellulose (CRC) suspension had typical characteristics of regenerated cellulose and was used to color polyurethane (PU). The resulting colored PU films exhibited excellent color fastness/resistance to leaching when soaked in water. This study demonstrated a way of alleviating the environmental burden of waste cotton fabrics by converting them to high value-added colored waterborne cellulose suspension. Preparation and application of CRC suspensions from waste cotton fabrics

Recyclable reactive dyeing of cotton fabrics was achieved in a heterogeneous non-aqueous binary solvent system. Ethyl octanoate (EO) and dimethyl sulfoxide (DMSO) were selected as exhaustion medium and solvating medium respectively. The solvents were immiscible at room temperature but formed a continuous phase upon heating and agitation, allowing for simple separation after dyeing. Sufficient swelling of the cotton fabric and excellent dye substantivity could be achieved by tuning ratio of the DMSO and EO. Compared with conventional aqueous dyeing, the solvent-based process required up to 40% less amount of dye and no inorganic salts. The dyeing sequence could be repeated 10 times. At the end of each dyeing cycle, 98.5 v% each of EO and DMSO was recovered and reused. The process was generally applicable to commercial monochlorotriazine dyes with consistently good shade build-up and colorfastness. Therefore, the heterogeneous DMSO/EO dyeing system provides a promising solution to the environmental problems associated with reactive dyeing of cotton in a source-controlled manner.

Waterborne acrylic latex has been widely used for its decent performance and less emission of volatile organic compounds. In the present study, regenerated nanocellulose suspension from microcrystalline cellulose (MCC) and wood pulp toward improving waterborne polyacrylate (PA) latex sag resistance was evaluated. Rheology behavior of PA latex-regenerated nanocellulose (RC) was investigated. PA latex-RC displayed a “gel-like” behavior and had a desirable shear thinning property. Moreover, sag resistance of PA latex was evaluated by creep behavior. Results showed that deformation of PA latex at constant stress obviously decreased with an increase of the RC concentration. Meanwhile, PA latex showed high recovery of strain (>90%) with 2% RC concentration after removal of stress, which may be related to the reinforcement from the RC entanglements and their interaction. In addition, the properties of dry PA film with RC were also evaluated. The tensile strain, tensile stress and thermal stability of the films were slightly improved, while optical transparency slightly compromised with 2% RC concentration. Overall, the results suggested that RC is a promising biomass material for improving the sag resistance of waterborne acrylic latex.

Dually self-reinforced Poly(e-caprolactone) (PCL) composites were prepared to broaden its load-bearing applications as tissue engineering scaffolds. The composites were prepared from bi-component PCL yarns composed of self-nucleated PCL drawn fibers and PCL matrix by a combined process of yarns winding and hot pressing. Differential Scanning Calorimetry (DSC) results showed that incorporating of self-nucleating agents can improve the melting points of the fibers, creating a process temperature window for hot pressing. The orientation parameters of the fibers were accurately measured by Confocal Raman microscopy (CRM) and the results showed that the orientation parameter of the fibers could be up to 0.9 after drawn. Tensile tests showed that the self-nucleated drawn fibers had stronger mechanical properties than the control fibers with the same draw ratios. The hot pressing parameters (temperature and pressure) were also optimized during hot-pressing. The Young's modulus and break strength of the dually self-reinforced composites in longitudinal direction could be up to 118% and 400% higher than that of pristine PCL although their elongation at break decreased. Decline of mechanical properties of the composites in transverse direction was not observed, indicating good adhesion between the fibers and the matrix, which was confirmed by scanning electron microscope analysis.

It is desirable for catalyst supports to be biodegradable, easily-modifiable, and possessing high surface area. In this work, thiolated nanocellulose sponge was prepared from hydrolytic silane condensation of cellulose nanofibrils (CNF) and used as a green support to immobilize copper cations via in situ CuII to CuI reduction and complexation. The sponge featured high porosity (90.5%) and low density (29.4 mg/cm3) with regular morphology. The sponge easily recovered 94% of its original shape in water after experiencing 80% deformation under stress of 95 kPa. When used in catalyzing hydroboration of alkynes, excellent conversion and up to 99% regioselectivity were achieved with the copper-loaded sponge. The sponge-supported catalysts worked well in the absence of additional ligands, had a broad substrate scope, and retained 93% of their activity after six catalytic cycles. This simple and scalable strategy offers an efficient route for immobilizing metal catalysts on porous supports.

A readily modifiable cellulose sponge was prepared from cellulose acetoacetate (CAA). Facile postsynthetic modification with primary amino-containing modifiers such as octadecyl amine (ODA), cysteine (CYS), and l-glutamic acid (GLU) could be achieved demonstrating the ease of anchoring a broad selection of functional groups to the surface of the sponges. This postsynthetic modification process was systematically characterized by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy, which confirmed the formation of the enamine bonds. Besides, the microstructures and mechanical properties of the sponges were well preserved throughout the postsynthetic modification process. The enamine bonds, as one of the dynamic covalent bonds, were easily formed under mild and neutral conditions and broken under exposure to a low pH stimulus. The enamine bonds were used to modify the CAA sponges, which can achieve the versatility and recycling of cellulose porous materials. Therefore, the resulting...

Self-powered electronic sensors and devices are suitable for use in applications such as health monitoring and information collection under battery-free conditions. Thermoelectric (TE) materials can utilize the temperature difference between the body and environment to achieve self-power. In this work, a flexible cellulose-based TE sponge (CP:PP sponge) was prepared via the electrostatic assembly of poly(3,4-ethylenedioxythiophene):poly (styrene sulfonate) (PEDOT:PSS) on cellulose sponges crosslinked with branched polyethylenimine (CP sponge). X-ray photoelectron spectroscopy (XPS) confirmed the adsorption of the PEDOT:PSS onto the CP sponge. The 3D structures, which were composed of thin sheets, typical of cellulose sponges, were maintained within the CP:PP sponges. These CP:PP sponges exhibited reasonable piezoresistive characteristics and excellent flexibility. Upon the application of several press-release cycles, the resistance varied without attenuation. It was demonstrated that the electrical conductivity of the sponge could be enhanced from 2 mS/cm to 6.7 mS/cm via further assembly of the PEDOT:PSS using an immersive layer-by-layer (LbL) strategy, and the thermal conductivity was maintained as 0.0449 W/mK. The maximum figure-of-merit (ZT) value was 1.88 × 10−6 at 310 K. A TE generator was fabricated by sandwiching the as-prepared CP:PP sponge, with enhanced electric conductivity and inherent low thermal conductivity, between commercial cotton fabrics. At an ambient temperature of 291 K, the device was shown to generate a voltage of 0.3 mV when one side of the device was attached to forearm skin (307 K). Such CP:PP sponges could potentially be used in artificial intelligence products or remote medical monitoring devices as general, flexible thermal energy harvesting materials.

Thiol-functionalised cellulose sponges were conveniently synthesised by reacting (2,2,6,6-tetramethylpiperidin-1-yl)oxyl oxidised cellulose nanofibrils (CNF) with (3-mercaptopropyl)-trimethoxysilane (MPTMS) at room temperature. The sponges, whose structures resemble honeycombs, were systematically characterised using Fourier transform infrared spectroscopy, solid-state 13C nuclear magnetic resonance spectroscopy, elemental analysis, scanning electron microscopy, energy-dispersive X-ray spectroscopy and compression tests. It was shown that the sponges could be used to selectively remove Hg2+ from an aqueous solution containing other metal ions and had excellent adsorption capacities of up to 700 mg/g. The sorption isotherm followed the typical Langmuir model and the adsorption kinetics fit a pseudo-second-order model. X-ray photoelectron spectroscopy was applied to confirm that sulfur and oxygen had significant roles in the adsorption of Hg2+. The sponges also showed high reusability after three adsorption–desorption cycles. This paper provides a simple method to prepare highly efficient adsorbents for the adsorption of Hg2+ from aqueous solutions.

Durable flame retardant and antibacterial hybrid coatings were developed for cotton fabrics via simultaneous polymerization of dopamine and hydrolytic condensation of N3P3[NH(CH2)3Si(OC2H5)3]6. Silver nanoparticles were also introduced to the coatings by in situ reaction of AgNO3 with catechol moieties on polydopamine (PDA) in the absence of any external reducing agents. Energy dispersive spectrometer (EDS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) were employed to study the morphology and constitution of the coatings. Thermal stability and combustion behaviors were characterized with thermogravimetric analysis (TGA) and vertical flammability tests. Considerable flame retardancy was obtained for the modified cotton fabrics, which also exhibited decent antibacterial activities (99.99%) against Gram-positive bacteria S. aureus and Gram-negative bacteria E. coli. The modification was durable with largely intact flame retardancy and antimicrobial properties after 30 washing cycles.

In this study, cellulose nanofiber (CNF) sponges were successfully prepared and modified with temperature-responsive poly-(N-isopropylacrylamide) (PNIPAM) via surface-initiated atom transfer radical polymerization (SI-ATRP). The structure and properties of the obtained CNF-g-PNIPAM sponges were characterized with FTIR, SEM, TGA and compression tests. Water permeation experiments were carried out to investigate the temperature-sensitivity of the sponge, excellent water flow manipulation could be achieved. The CNF-g-PNIPAM sponge holds great potential in applications such as temperature-trigged microfluidic devices, water/oil separation and filtration.

Bismuth oxychloride (BiOI) has a good visible light responsive property due to their relatively narrow band gap, and its photocatalytic performance was further improved by doping ytterbium ions (Yb3+). This may be due to strong optical absorption in UV–visible light, effective separation of the photoinduced electron-hole pairs, and the capacity to up-convert Near-IR light into visible-light of Yb3+ ions. In this study, a facile solvothermal method was adopted to synthesize Yb3+ ions doped BiOI photocatalysts. The doped photocatalysts with molar ratios of 0, 0.5, 1, 1.5, 2 and 2.5% Yb3+ ions were prepared. The 2% Yb3+ ions doped BiOI exhibited the highest photocatalytic degradation efficiency on degrading Rhodamine B, which was two times higher than that of pure BiOI. Also Yb3+ ions doped BiOI showed high photocatalytic degradation on herbicide isoproturon. The prepared photocatalysts were characterized by SEM, XRD, UV–vis DRS. It indicated that the doping ions entered the lattice of BiOI crystals and improved the photocatalytic performance. The photocatalytic mechanism was also studied. This work provided the potential application of Yb3+ doped BiOI for the degradation of organic contaminants.

An injectable polysaccharide hydrogel based on cellulose acetoacetate (CAA), hydroxypropyl chitosan (HPCS), and amino-modified cellulose nanocrystals (CNC-NH2) was prepared under physiological conditions. CNC-NH2 acted as both physical and chemical cross-linker. The effects of CNC-NH2 loading on the mechanical properties, internal morphology and gelation time were investigated; the maximum storage modulus was observed for a gel containing 0.80 wt% of CNC-NH2. The structure and properties of the polysaccharide hydrogel were characterized by Fourier-transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, scanning electron microscopy, Raman spectroscopy and rheology testing. The polysaccharide hydrogel exhibited pH- responsive properties and excellent stability under physiological conditions. The hydrogel also exhibited self-healing behavior under acidic conditions via enamine bond exchange. In addition, CCK-8 cytotoxicity study with fibroblast L929 cells demonstrates good biocompatibility of CNCs reinforced hydrogels.

A robust and flexible cellulose nanofiber (CNF)-supported cryogel was prepared by chemical crosslinking method using γ-glycidoxypropyltrimethoxysilane (GPTMS) and branched polyethylenimine (PEI). FT-IR, elemental analysis, EDS and solid state 13C NMR analysis revealed that the PEI had been successfully modified on cellulose via reacting with GPTMS. The obtained flexible cryogel displayed a three-dimensional structure composed of thin sheet. The maximal shape recovery of the CNF-supported cryogel from a 50% compression strain was up to 93% of its original thickness. The cryogel contained abundant amino groups and proved to be efficient in removing Cu2+ from solution with a maximum Cu2+ uptake of 138 mg/g. The adsorption kinetics curve fitted the pseudo-second-order model and the equilibrium absorption capacity fitted the Langmuir model. Moreover, adsorption capacity of the cryogel was up to 75% after four adsorption–desorption cycles (15 days).

The CQDs-Bi20TiO32 photocatalysts exhibited high visible-light responsive photocatalytic activity. To achieve the cyclic utilization of CQDs-Bi20TiO32, the novel flexible CQDs-Bi20TiO32/PAN fiber membranes were prepared by a simple coaxial electrospinning technique. It was found that the CQDs-Bi20TiO32 photocatalyst could be firmly and uniformly fixed on the surfaces of electrospun fibers and the composite fiber membranes possessed the hierarchical macro- and mesoporous structure. The loaded CQDs-Bi20TiO32 endowed the composite fiber with an obvious photocatalytic activity for the degradation of the herbicide isoproturon under visible light irradiation. Among these samples, S3 at photocatalyst dosage 15 w/v% had the highest degradation efficiency for isoproturon. Meanwhile, the core-shell structured inorganic-organic hybrid fiber membranes have a significant advantage in the recyclability for photocatalyts. The flexible CQDs-Bi20TiO32/PAN electrospun fiber membranes would have potential applications in efficient removal of organic contaminants.

Preparation of cellulose nanofibril (CNF)-reinforced, biodegradable polymer composites is challenging in that it’s hard to achieve good dispersion of the hydrophilic cellulose fibers in a hydrophobic polymer matrix. In this work, we developed a surfactant-free and efficient process to prepare CNF-reinforced poly (lactic acid) (PLA) composites from an aqueous dichloromethane Pickering emulsion self-emulsified by CNFs. CNF/PLA composites of homogeneous dispersion were obtained upon evaporation of CH2Cl2, filtration, drying and hot-pressing. Differential scanning calorimetry measurement revealed an enhanced crystallization capacity of the CNF/PLA composites. Thermogravimetric analysis indicated an increase of onset degradation temperature. The composites displayed an enhanced storage modulus compared with neat PLA throughout the testing temperature range, and especially in the high-temperature region (>70 °C). Enhancements of the flexural modulus and strength were also achieved.

A novel low add-on dyeing process of cotton fabric with C.I. Reactive Black 5 has been implemented successfully with the assistance of dye-jet ejector units to produce precise wet pick-up ranging from 20% to 50%. The steaming process of the low add-on technology was investigated through evaluating the effects of relative humidity, steaming temperature, steaming time and water ratio on the surface temperature of the wet fabric and their influence on the dye properties, as well as the effect of the wet pick-up on dye properties. The optimal dyeing process was also conducted, including build-up properties and the concentrations of the alkaline agent and the electrolyte via the evaluation of the color strength ( K/ S value) and dye fixation rate. A comparison was made between the novel low add-on dyeing process and conventional dyeing process by assessing the dye properties, color shade and color levelness. The results indicated that the fabric dyed with the low add-on process had excellent washing fastness, rubbing fastness, a similar color shade and superior levelness in comparison with conventional one-bath pad-steam dyeing.

The visible light-responsive photocatalyst Ag-AgBr@Bi 20 TiO 32 exhibited both high photocatalytic activity and antibacterial activity. To achieve the efficient immobilization of Ag-AgBr@Bi 20 TiO 32 , coaxial electrospinning technology was adopted to fabricate the novel multifunctional PAN/Ag-AgBr@Bi 20 TiO 32 electrospun fiber mats. The characterization results indicated that the surface of each electrospun fiber was uniformly covered with the Ag-AgBr@Bi 20 TiO 32 photocatalyst. The loaded Ag-AgBr@Bi 20 TiO 32 endowed the composite fiber mats with an excellent photocatalytic activity and recyclability for the degradation of the herbicide isoproturon under visible light irradiation. Meanwhile, it showed efficient antibacterial activity against both the Gram-positive bacteria S. aureus and Gram-negative bacteria E. coli due to the synergistic effect between the silver, which has innate antibacterial activity, and active species, which have a strong oxidation ability, generated on the surface of the photocatalyst. Given the above research results, the flexible PAN/Ag-AgBr@Bi 20 TiO 32 electrospun fiber mats would have potential applications in the water/air purification field and biochemical protective clothing.

In this work, aluminum hydroxide aerogel was successfully assembled on polysulfonamide fabrics by sol–gel forming method to improve the thermal insulation and flame resistance properties. The presence of aluminum hydroxide aerogels assembled on the surface of polysulfonamide fabrics was verified by the scanning electron microscopy. The aerogel was crystalized in γ-AlOOH boehmite form characterized by X-ray powder diffraction. The heat insulation and flame resistance of polysulfonamide fabrics were improved by coating aluminum hydroxide aerogels. When the molar ratio of propylene oxide to aluminum chloride hexahydrate was 4:1, the prepared aluminum hydroxide aerogel marked as SAl-2 had the largest pore volume with the value of 2.33 cm3/g, the corresponding apparent density was 0.172 g/cm3, the specific surface area was 392 m2/g, the average pore diameter was 18.6 nm, and it gave the best thermal insulation property. Compared with the original polysulfonamide fabric, the thermal conductivity of the composite fabric was decreased from 0.0513 to 0.0301 W/(m·K). When the molar ratio of propylene oxide to aluminum chloride hexahydrate was 3:1, the prepared aluminum hydroxide aerogel marked as SAl-1 had the smallest pore volume with the value of 0.72 cm3/g, the corresponding apparent density was 0.645 g/cm3, the specific surface area was 293 m2/g, the average pore diameter was 10.9 nm, and it gave the best flame resistance property. Compared with the original polysulfonamide fabric, the vertical burning damage length was shorted from 4.90 to 1.30 cm.

To achieve the efficient utilization of solar light energy, novel carbon quantum dots (CQDs) modified Bi 20 TiO 32 photocatalysts were prepared with different CQDs contents. The obtained photocatalysts were characterized by XRD, FT-IR, XPS, SEM, HRTEM, photoluminescence (PL) spectra, transient photocurrent and electrochemical impedance spectroscopy (EIS). The results showed that the CQDs were uniformly deposited on the surface of Bi 20 TiO 32 . The as-prepared CQDs/Bi 20 TiO 32 composites were capable of utilizing both the visible and near-infrared light due to the active role of the carbon nanodots as up-converting photo-sensitizers. By the LC–MS-MS analysis, the herbicide isoproturon molecular could be firstly degraded to several intermediates and then completely mineralized. The CQDs/Bi 20 TiO 32 photocatalysts with a CQDs content of 1% exhibited the optimum photocatalytic activity and could degrade 98.1% of isoproturon within 48 h. Its degradation rate constant was approximately 4.3 times higher than that of pure Bi 20 TiO 32 . The main active species in the photo-degradation process was h + and O 2 − . To further study the recycle ability of CQDs/Bi 20 TiO 32 photocatalyst, the PAN supported CQDs/Bi 20 TiO 32 nanofiber mat was prepared by coaxial electrospinning method. The composite nanofiber materials showed good photocatalytic activity and recyclability, which had potential applications in water/air purification field and biochemical protective clothing.

Thiol–ene click reaction was employed to synthesize a flexible hydrophilic cellulose sponge. The reactive vinyl group was introduced by silanization treatment with vinyl-trimethoxysilicane (VTMO), and the resulting silylated cellulose sponge (SCS) can be subsequently functionalized with various thiol-containing compounds such as 3-mercaptopropionic acid, via temperature induced thiol–ene reactions. The hydrophilic cellulose sponge thus prepared displayed an excellent mechanical strength of 70 KPa at 80% compression strain. The prepared sponge features hydrophilic and underwater oleophobic properties and was used in gravity-driven removal of oil from oil-in-water emulsions and oil/water mixtures with a high separation efficiency. The separation efficiency remained 100% after 10 cycles for an oil/water mixture and 95% after 6 cycles for an oil-in-water emulsion.

A simple two-step impregnation method was used to prepare copper nanoparticles coated cotton fabric. In which, dopamine firstly self-polymerized to polydopamine membrane on the cotton fabric surface, then copper nanoparticles were obtained and bound onto the cotton fabric using polydopamine as a reductant and binder. Field emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS) and Inductively Coupled Plasma Optical Emission Spectrometer (ICP-OES) were used to observe the surface morphology and analyze the elemental composition as well as their surface chemical states of all samples. The results confirmed the formation of polydopamine film and copper nanoparticles. The results of contact angle measurements and antibacterial tests showed that the modified cotton fabrics had durable sticky superhydrophobicity and considerable antibacterial activity.

Accurate real-time determination of each dye in combination dyeing is critical to the control of dyeing process, which plays an important role in upgrading the dyeing techniques of textile. In this work, Raman spectroscopy was applied to dyeing baths containing multiple dye species of varying structures to quantitatively monitor the dyeing process of each individual dye. Quantitative models were successfully established by partial least squares (PLS) for all combinations of the nine commonly used reactive dyes studied. The correlation coefficients were greater than 0.99, the root mean squared errors of calibration (RMSEC) were less than 0.2650 and the root mean squared errors of prediction (RMSEP) were less than 0.1340, even for the three-component mixture of Reactive Red 239 (RR239), Reactive Yellow 176 (RY176) and Reactive Blue 194 (RB194), which are similar in structures. The model was shown to be valid in the presence of added electrolytes (sodium sulfates). Real-time adsorption monitoring based on the model revealed that the dyes interacted with one another and competed for active sites. The adsorption kinetics obtained by Raman analysis shed light on dye compatibility and could be used to guide the design of dyeing recipe and dyeing process for optimum color reproduction. In addition, in situ monitoring by Raman spectroscopy maybe integrated with real-time on line control of dyeing parameters for fully automated production of dyed fabrics.

In this study, ultra-thin and easily dispersible g-C3N4 nanosheets were obtained by a simple wet ball-milling process. Morphological and structural analysis showed that increasing ball-milling speed resulted in a decrease in both particle size and the number of stacked layers in g-C3N4 nanosheets, hence improving their dispersion stability. Thinner nanosheets obtained by ball milling at 150 rpm also had higher photocatalytic capacity, with up to 2.2 times enhancement comparing with untreated g-C3N4. The feasibility of the g-C3N4 nanosheets for photodegradation of aqueous organic contaminants was demonstrated using polluted water sampled from Jingyue Lake in Donghua University, a local lake.

The photocatalytic performance of pure Bi20TiO32 was restricted by the fast charge recombination. Considering the high carrier mobility of reduced graphene oxide (rGO), a series of rGO/Bi20TiO32 composites were successfully fabricated by a facile in suit method with the aim to promote the charge separation. Inspiringly, 2% rGO/Bi20TiO32 composite showed much higher photocatalytic activity for the degradation of non-biodegradable Rhodamine B (RhB) under visible-light irradiation, which was 10 times higher than that of pure Bi20TiO32. The enhanced photocatalytic performance of rGO/Bi20TiO32 composites could be attributed to their stronger optical absorption in the visible-light region and rapider separation efficiency of the photogenerated electron-hole pairs. The underlying photocatalytic mechanism was revealed through the Photoluminescence spectra and free radical capture experiment. This work provided a rational design for the development of high efficient visible-light photocatalysts.

The organosilicon functionalized cyclotriphosphazene (N3P3[NH(CH2)3Si(OC2H5)3]6) was synthesized and characterized by nuclear magnetic resonance (NMR) and Fourier transform infrared spectra (FTIR), then it was applied to cotton fabrics through a convenient pad-dry-cure process to fabricate flame retardant coating with different add-on values. The coating on cotton fabrics was confirmed by the scanning electron microscopy (SEM). Excellent flame retardancy was found from limited oxygen index (LOI) and vertical burning test. The coating induced an earlier decomposition of cellulose, enhanced the formation of the stable char and significantly reduced the heat release rate. Moreover, flame retardancy of the coated fabrics did not change significantly after 30 soaping cycles.

A novel triazine oligoimides containing silicone charring agent (TSCA) was prepared and used as charring agents in poly(ethylene terephthalate) (PET)/hexakis (4-phenoxy) cyclotriphosphazene (PNCP) flame retardant system. Limited oxygen index, microscale combustion calorimetry, thermogravimetric analyses, and environment scanning electron microscopy tests were used to study the flame retardance and mechanism of samples. The results revealed that there was a good synergistic effect between TSCA and PNCP in flame retardant PET. The new flame retardant system induced the acid catalytic charring at higher temperature range, enhanced the formation of the integrity and stable char layer, and significantly reduced heat release capacity. Moreover, the prepared PET/PNC/TSCA composites exhibited improved thermal stability and desirable mechanic properties. POLYM. COMPOS., 2016. © 2016 Society of Plastics Engineers

The aggregation behaviors of methylcellulose (MC) in aqueous solution were investigated using all-atom molecular dynamic simulations (MD). The interactions between MC chains and water molecules at different temperatures were investigated by a series of MD analyses, such as the solvent accessible surface area, number of hydrogen bonds, radial distribution functions and the interaction energies. Constant temperature simulations and heating simulations of MC aqueous solution were carried out in this work. In the simulations at three constant temperatures (25 °C, 50 °C and 75 °C), the aggregation behaviors of MC chains were affected by the temperature. In the heating simulation (25 °C ∼ 75 °C), temperature increases were accompanied by decreases in interactions between MC and water molecules, and by increases in interactions between MC chains, which led to the aggregation of MC chains. The degree of aggregation of MC chains increased with the rise of temperature.

Herein, the acetoacetyl group was directly anchored on the surface of cotton fabric (Cotton-acac) via heterogeneous transesterification. This surface modification strategy was systematically characterized by Fourier transform infrared spectroscopy, solid-state 13C nuclear magnetic resonance spectroscopy, X-ray diffraction, and thermogravimetric analysis, which confirmed it was a mild and efficient process. Besides, Cotton-acac was used as the versatile intermediate post-modified with gentamicin (Gen) and octadecyl amine (ODA) molecules to impart cotton fabric dual functions with hydrophobic and antibacterial properties. The resulting cotton fabric showed dual and outstanding hydrophobic and antibacterial performance against E. coli and S. aureus, with the bactericidal rates of over 99.99% and the water contact angle of 145°even after 10 cycles of standard washing. Therefore, the heterogeneous modification provided a benign and versatile method for regulating the interfacial properties of the cellulosic materials, with the possibility of post modification for various applications through the acetoacetyl chemistry.

Various metal-organic frameworks (MOF) are highly effective catalysts for detoxifying chemical warfare agents (CWAs). In this study, we reported a MOF-loaded cellulose sponge for fast degradation of CWAs simulant. In situ growth of UiO-66-NH2 onto γ-Glycidoxypropyltrimethoxysilane (GPTMS) modified cellulose sponge was achieved. This sponge featured high porosity (88%), high specific surface area (310.5 g/m2) and low density (36 mg/cm3). The UiO-66-NH2 functionalized cellulose sponge showed excellent catalytic activity for detoxifying 4-Nitrophenyl Phosphate (DMNP) and the half-life was as short as 9 min.

In this paper, we demonstrated an efficient continuous flow reactor packed with nanocellulose sponges made from the sustainable wood pulp. The key component of such reactor, a wood pulp derived nanocellulose sponge loaded with metal catalysts, exhibited high porosity and interconnected porous structure, providing low flow resistance and long-term stability to the flow reactors. The packing material showed good performance in Huisgen cycloaddition in both batch and continuous flow systems. Key comparisons between two systems including reaction kinetics, operating conditions and safety were particularly discussed. Various triazoles have been afforded with >99% conversion, even for gram scale reaction in flow systems. The continuous flow reactors we developed were easily derivatized, thus forming a general, economic and readily scalable platform as promising synthesis tools.

A novel organic-inorganic hybrid polyphosphazene modified manganese hypophosphite (PZS-MnHP) shuttles was facilely fabricated and applied in enhancing the flame retardance and anti-dripping behavior of PET. The PET containing 5 wt% PZS-MnHP shuttles (PET/FR5.0) possessed a LOI value of 25.3% and corresponding melt-dripping was greatly restricted with few droplets. Incorporating 5 wt% PZS-MnHP shuttles also brought about dramatic decrease in the fire hazard of PET, for instance, 57.0% maximum reduction in heat release rate. Moreover, the tensile strength of PET/FR5.0 composite was gradually increased from 50.87 MPa to 55.68 MPa, relevant elongation at break was enhanced by 7.2% compared with that of PET. The flame-retardation mechanism of PZS-MnHP shuttles in PET was also systematically investigated. The results showed PZS-MnHP shuttles extremely accelerated the formation of intumescent char, cutting off the supply of external oxygen and heat. Moreover, inflammable gases including SO2 and NH3 released from PZS-MnHP shuttles efficiently diluted combustible organic volatiles in burning area, further blocking the spread of fire.

A general way to prepare bio-based polymer colorant by reactive dyeing of regenerated cellulose (RC) in dimethyl sulfoxide (DMSO) was established. Up to 40% higher dye utilization was achieved compared with aqueous reactive dyeing of RC for two reasons. 1. Lower liquor ratio of 1:9 could be applied for the concentrated RC suspensions in DMSO was less viscous. 2. Dye loss from solvolysis was turned off in DMSO. The method was generally applicable to RCs made from wood pulp, waste cotton, and bamboo pulp. The dyeing process has minimum influence on the morphological, rheological, and thermal properties of RC. The colored RCs thus prepared were used to prepare colored polymer composites via a Pickering emulsion approach, and to color cotton, cotton blend, and viscose fabrics via a printing approach. Therefore, it holds great potential as renewable and biodegradable pigments for making colorful composites, ink, textile dyeing and finishing.