Dynamic Poly(dimethylsiloxane) Brush Coating Shows Even Better Antiscaling Capability than the Low-Surface-Energy Fluorocarbon Counterpart.

Scale formation is a significant problem in a wide range of industries, including water treatment, food processing, power plants, and oilfield production. While surface modification provides a promising methodology to address this challenge, it has generally been believed that surface coatings with the lowest surface energy, such as fluorocarbon coatings, are most suitable for antiscaling applications. In contrast to this general knowledge, here we show that a liquid-like coating featuring highly mobile linear poly(dimethylsiloxane) (LPDMS) brush chains can bring an even better antiscaling performance than conventional perfluoroalkylsilane coatings, despite the fact that the former has much higher surface energy than the latter. We demonstrate that the LPDMS brush coating can more effectively inhibit heterogeneous nucleation of scale on a substrate compared with common perfluoroalkylsilane or alkylsilane coatings, and the dynamic liquid-like characteristic of the LPDMS brush coating is speculated to be responsible for its excellent nucleation inhibiting ability by reducing the affinity and effective interface interaction between the substrate and the scale nucleus. Our findings reveal the great prospect of using liquid-like coating to replace environmentally hazardous fluorine-containing organic ones as a green and cost-effective solution to address the scale problem with enhanced antiscaling performance.

Effect of chronic exposure to microplastic fibre ingestion in the sea cucumber Apostichopus japonicus.

Microplastics (MPs) in the form of microfibres (MFs) are of great concern because of their size and increasing abundance, which increase their potential to interact with or be ingested by aquatic organisms. Although MFs are the dominant shape of MPs ingested by sea cucumbers in habitats, their effect on sea cucumbers remains unclear. This study examined the effect of dietary exposure to MFs on the growth and physiological status of both juvenile and adult Apostichopus japonicus sea cucumbers. MFs were mixed into the diet of sea cucumbers for 60 d at environmentally relevant concentrations of 0.6 MFs g-1, 1.2 MFs g-1 and 10 MFs g-1. Dietary exposure to MFs, with concentrations at or above those commonly found in the habitats, did not significantly affect the growth and faecal production rate of either juvenile or adult sea cucumbers. However, a disruption in immunity indices (acid phosphatase and alkaline phosphatase activity) and oxidative stress indices (total antioxidant capacity and malondialdehyde content) was observed in juvenile and adult sea cucumbers, indicating that these indices might be useful as potential biomarkers of the exposure to MF ingestion in sea cucumbers. This study provides insights into the toxicity mechanism of MF ingestion in a commercially and ecologically important species.

A deposit-feeder sea cucumber also ingests suspended particles through the mouth.

Although the sea cucumber Apostichopus japonicus has been characterised as a deposit feeder, nutrients sourced from the water column have been recorded in the intestines of this species. However, the mechanisms whereby nutrients in the water enter the intestinal tract of A. japonicus, and whether other suspended particles can be ingested via the mouth of A. japonicus adults, remain unknown. Here, we reveal how A. japonicus ingests suspended particles through the mouth. We used synthetic particles and video recording to confirm the suspension uptake by the sea cucumber. Apostichopus japonicus continued to ingest suspended particles (if present) over time, and the particle ingestion rate was positively correlated with the concentration of suspended particles (Pearson correlation: r=0.808). Additionally, clearance rates of the suspended particles ranged from 0.3 to 0.9 l h-1 The findings of this study thus provide evidence of a previously undescribed particle uptake mechanism in a commercially important species.

Cellulose-Based Strips Designed Based on a Sensitive Enzyme Colorimetric Assay for the Low Concentration of Glucose Detection.

High-purity cellulose membranes prepared via a green pathway were used to attempt to enhance their performance of glucose detection compared with that of traditional filter paper. In this work, cellulose-based strips (CBS) for the low concentration of glucose detection have been designed based on a fast, sensitive, and easy enzyme colorimetric assay from porous and high-purity cellulose membranes (CM). Different from the traditional paper-based sensors that were made of commercially available filter paper, the cellulose-based membranes matrix was fabricated by a "green" route in that cellulose was dissolved in an aqueous NaOH/urea solution, and then modified by the sodium periodate oxidation method to immobilize the glucose oxidase (GOX) and horseradish peroxidase (HRP) with Schiff-base reaction. The structure and properties of CM and CBS were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray mapping (EDS), Fourier-transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), etc. SEM images showed a porous, interpenetrating structure of CM, which benefited the enzyme immobilization and enzymatic reaction. When glucose solution was dropped onto the CBS, the color change from colorless to blue was only 5 min. The limit of detection (LOD) is 0.45 mM in the linear range of glucose from 1 to 11 mM. Moreover, the CBS had also been successfully used for glucose determination in real urine samples, and the color changes can be easily recorded by a simple camera to achieve the semiquantitative detection of glucose. This work provided a new design strategy for the cellulose-based functional materials which could be applied in biosensors, drug carriers, and biomedicine.

Upgraded cellulose and xylan digestions for synergistic enhancements of biomass enzymatic saccharification and bioethanol conversion using engineered Trichoderma reesei strains overproducing mushroom LeGH7 enzyme.

Crop straws provide enormous lignocellulose resources transformable for sustainable biofuels and valuable bioproducts. However, lignocellulose recalcitrance basically restricts essential biomass enzymatic saccharification at large scale. In this study, the mushroom-derived cellobiohydrolase (LeGH7) was introduced into Trichoderma reesei (Rut-C30) to generate two desirable strains, namely GH7-5 and GH7-6. Compared to the Rut-C30 strain, both engineered strains exhibited significantly enhanced enzymatic activities, with ß-glucosidases, endocellulases, cellobiohydrolases, and xylanase activities increasing by 113 %, 140 %, 241 %, and 196 %, respectively. By performing steam explosion and mild alkali pretreatments with mature straws of five bioenergy crops, diverse lignocellulose substrates were effectively digested by the crude enzymes secreted from the engineered strains, leading to the high-yield hexoses released for bioethanol production. Notably, the LeGH7 enzyme purified from engineered strain enabled to act as multiple cellulases and xylanase at higher activities, interpreting how synergistic enhancement of enzymatic saccharification was achieved for distinct lignocellulose substrates in major bioenergy crops. Therefore, this study has identified a novel enzyme that is active for simultaneous hydrolyses of cellulose and xylan, providing an applicable strategy for high biomass enzymatic saccharification and bioethanol conversion in bioenergy crops.

A Nature-Derived, Hetero-Structured, Pro-Healing Bioadhesive Patch for High-Performance Sealing of Wet Tissues.

Tissue adhesives are promising alternatives to sutures and staples to achieve wound closure and hemostasis. However, they often do not work well on tissues that are soaked in blood or other biological fluids, and organs that are typically exposed to a variety of harsh environments such as different pH values, nonhomogeneous distortions, continuous expansions and contractions, or high pressures. In this study, a nature-derived multilayered hetero-bioadhesive patch (skin secretion of Andrias davidianus (SSAD)-Patch) based on hydrophilic/hydrophobic pro-healing bioadhesives derived from the SSAD is developed, which is designed to form pressure-triggered strong adhesion with wet tissues. The SSAD-Patch is successfully applied for the sealing and healing of tissue defects within 10 s in diverse extreme injury scenarios in vivo including rat stomach perforation, small intestine perforation, fetal membrane defect, porcine carotid artery incision, and lung lobe laceration. The findings reveal a promising new type of self-adhesive regenerative SSAD-Patch, which is potentially adaptable to broad applications (under different pH values and air or liquid pressures) in sutureless wound sealing and healing.

Water-in-water emulsion stabilized by cellulose nanocrystals and their high enrichment effect on probiotic bacteria.

HYPOTHESIS: The effect of the molecular weight and polymer concentration on the partition behavior of aqueous two-phase systems (ATPs) is significant for constructing water-in-water (W/W) emulsions. Hence, a long-term stable W/W emulsion system might be obtained through selecting the appropriate stabilizer and component phases, which could be a possible carrier for probiotics. EXPERIMENTS: Compared with the reported molecular weight difference between polyethylene oxide (PEO) and dextran (DEX) systems, PEO and dextran with lower molecular weight had been used for constructing the water in water (W/W) emulsion system. The W/W emulsions were stabilized using cellulose nanocrystals (CNCs), and the potential application of the W/W emulsion for the encapsulation of Lactobacillus was explored. FINDINGS: Emulsion stability exhibited a "dose-effect" relationship with the CNCs concentration and was decreased with the increase of the DEX concentration. The emulsion phase separation rate was increased with increasing ionic strength and temperature. Both Lactobacillus Plantarum and Lactobacillus helveticus were highly inclined to the DEX phase, and the emulsion droplets were deformed and aggregated when the encapsulation amount was increased. This long-term stability would provide a promising approach for designing high-density culture and fermentation of probiotics.

Microplastics in canned, salt-dried, and instant sea cucumbers sold for human consumption.

Determining the amount of microplastics (MPs) in food is key to clarifying their potential toxicity to humans. Here, we collected canned, instant, and salt-dried sea cucumbers Apostichopus japonicus, the most valued sea cucumbers, from Chinese markets to determine their content of MPs. Sea cucumbers contained MPs in the range of 0-4 MP individual-1, an average of 1.44 MP individual-1, and 0.081 MP g-1. Accordingly, consuming 3 g of sea cucumbers could result in an exposure risk of an average of 0.51 MPs, 0.135 MPs, and 0.078 MPs day-1 for canned, instant, and salt-dried sea cucumbers, respectively. MPs were in size range of 12-575 µm, and fibrous shape was dominant. Furthermore, among the five polymers identified, polypropylene showed the highest energy binding with two catalysts engaged in organic chemical oxidation. This study extends the knowledge regarding MPs occurrence in food and provides a theoretical basis for MPs toxicity in humans.

Existence of microplastics in the edible part of the sea cucumber Apostichopus japonicus.

Microplastics (MPs; ≤ 5 mm) have become a potential threat to human health due to the widespread detection of MPs in foods consumed by humans. Here, we investigated the potential of MP occurrence in the main edible part of the most valuable species of sea cucumbers (Apostichopus japonicus). Laboratory experiments showed that fluorescent MPs and microfibers (MFs) could transfer into the body wall of the sea cucumber. The evidence revealed that these MPs enter the body wall via the outer surface. Although these MPs decreased after the sea cucumbers were transferred to clean water, traces of MPs (at least one MP particle) were found up to 60 d post-transfer. To validate these laboratory observations, sea cucumber samples were collected from the field. MPs were found in 86% of live and processed sea cucumber samples. The MP abundances in the field samples ranged from 0-15 MPs animal-1 and 0-2 MP g-1. The isolated MPs were mainly MFs, constituting 81% of MPs, followed by fragments, films, and beads. Fourier transform infrared spectroscopy revealed that the polymer composition of the isolated MPs mainly included rayon, followed by polyester and chlorinated polyethylene. The findings of this study demonstrated that the body walls of farmed and processed sea cucumbers contain MPs, thus highlighting the need to control MP pollution during the farming and processing of sea cucumbers.

Improvement of O/W emulsion performance by adjusting the interaction between gelatin and bacterial cellulose nanofibrils.

This study was designed to improve the stability of medium internal phase emulsion by adjusting the electrostatic interaction between gelatin (GLT) and TEMPO-oxidized bacterial cellulose nanofibrils (TOBC). The influences of polysaccharide-protein ratio (1:10, 1:5, and 1:2.5) and pH (3.0, 4.7, 7.0, and 11.0) on the emulsion properties were investigated. The droplet size of TOBC/GLT-stabilized emulsion was increased with the TOBC proportion increasing at pH 3.0-11.0. Additionally, emulsion had a larger droplet size at pH 4.7 (the electrical equivalence point pH of mixtures). However, the addition of TOBC significantly improved the emulsion stability. The emulsions prepared with TOBC/GLT mixtures (mixing ratio of 1:2.5) at pH 3.0-7.0 were stable without creaming during the storage. It was because the formation of nanofibrils network impeded the droplet mobility, and the emulsion viscosity and viscoelastic modulus were increased with the addition of TOBC. These findings were meaningful to modulate the physical properties of emulsions.

Growing Pd NPs on cellulose microspheres via in-situ reduction for catalytic decolorization of methylene blue.

Dyeing industry highly contributes to environmental pollution and this needs to be addressed on priority. Pd NPs/CMs, a highly efficient and reusable catalyst for methylene blue (MB) decolorization, were fabricated by in-situ reduction method based on the cellulose microspheres (CMs). Pd NPs/CMs were characterized for the structure and catalytic performance by spectroscopic techniques such as SEM, EDS, XRD, IR, XPS, porosity, zeta potential, MS, and UV-visible spectroscopy, which all demonstrated that Pd NPs were distributed on the cellulose microspheres uniformly and exhibited excellent catalytic performances to decolorize a model organic dye MB in the presence of NaBH4 with catalytic efficiency higher than 99.8%. More importantly, Pd NPs/CMs were proven to show excellent reusability for at least five cycles. Decolorization mechanism of MB, via the destruction of the chromophores (CN and S) of MB, was established with the help of MS combined with IR and XPS. Blank experiments using pure cellulose microspheres were carried out simultaneously to estimate the level of catalytic capacity achieved to Pd NPs/CMs. These materials proved themselves having great potential in large scale applications to treat dye-containing wastewater.

Chlorine Rechargeable Halamine Biocidal Alginate/Polyacrylamide Hydrogel Beads for Improved Sanitization of Fresh Produce.

Traditional fresh produce washing systems mainly rely on mechanical forces and usage of chlorine bleach solutions to aid in removal and sanitization of microorganisms attached on surfaces of fresh produce during washing processes. Frequent outbreaks of foodborne diseases from ready-to-eat produce indicate insufficient sanitization of the washing processes. Herein, we present a scalable methodology for creating antimicrobial and chlorine rechargeable hydrogel beads using an in situ formed network of polyacrylamide and natural polysaccharide alginate through an emulsion polymerization. The resulting hydrogel beads exhibited robust mechanical strength, rechargeable chlorination capability, rapid up to 99.99% bacterial killing efficiency, and high produce sanitizaiton efficiency, enabling the hydrogel beads as a promising additive in chlorine sanitization to effectively sanitize the produce and automatically being recharged and reused.

Functionalized phosphorylated cellulose microspheres: Design, characterization and ciprofloxacin loading and releasing properties.

In this work, functionalized phosphorylated cellulose microspheres (CMP) were designed as a carrier for the ciprofloxacin (CIP) drug delivery system. The CMP has been developed from cellulose microspheres (CM) and phosphoric acid via an esterification reaction. CIP, an antibiotic drug as a model, was loaded onto CIP via hydrogen bonds and electrostatic interactions. A series of test results showed that the CIP was successfully incorporated and released from the prepared CMP without the loss of structural integrity or changing its functionality. The release kinetics and mechanism suggest that CIP release follows first-order kinetics and non-Fickian diffusion mechanism. The cytotoxicity behavior of CMP enables the material as a suitable vehicle for the safe release of CIP. The CIP loaded microspheres exhibited a significant antibacterial effect due to the CIP release and diffusion from the microspheres. This study provides insight into the design of suitable cellulose microspheres for CIP delivery.

Coalescence behavior of eco-friendly Pickering-MIPES and HIPEs stabilized by using bacterial cellulose nanofibrils.

O/W Pickering emulsions containing oil phase with different volume fractions (50-75 v%) were facilely prepared by using bacterial cellulose nanofibrils (BCNFs) alone. The effect of oil phase volume, storage time on the surface coverage, and coalescence rate of the Pickering-MIPEs and HIPEs (medium internal phase emulsions/high internal phase emulsions) were investigated. The Pickering-MIPEs/HIPEs exhibited excellent physical stability and low coalescence rate with droplet size varying from 32 to 91 µm. The increasing of particle contents could obviously decrease the droplet size and enhance the stability of the emulsions by strengthening the network structure and increasing the steric hindrance. The result of rheology analysis confirmed the formation of a three-dimensional network, endowing the exceptional stability of the emulsions. The emulsions revealed superb stability against a wide temperature (4-50 °C) range and salt condition (0-100 mM). This novel eco-friendly Pickering-MIPEs and HIPEs would provide great opportunities for their effective utilization in green-labelled food industry.

Construction of cellulose-based Pickering stabilizer as a novel interfacial antioxidant: A bioinspired oxygen protection strategy.

Oxygen protection/isolation is imperative to prevent the lipid oxidation since oxygen molecule is an ultimate quencher in photon conversion process. Inspired by the structural buildup of seeds from oil crops, a sustainable solid particle stabilizer with novel antioxidant activity was prepared by using cellulose and polyphenol. In this work, bacterial cellulose (BC) nanofibrils modified by tea polyphenols (TPs) was prepared and used as Pickering emulsifier for the O/W emulsion. BC nanofibirls exhibited excellent adsorption capacity up to 55 µg/mg, and the adsorption kinetics between BC and TPs were further investigated. After modification, the interfacial diffusion rate constant of BC was significantly increased to from 0.43 to 1.21 mN m-1 s-0.5. Moreover, the obtained O/W interfacial modulus of the dilatational elasticity was increased from 58 to 130 mN/m. Furthermore, the emulsions exhibited excellent free-radical scavenging activity at oil-water interface, suggesting a potential application in usage to extend the lifespan of the food containing polyunsaturated fats.

Water-insoluble dietary fibers from bamboo shoot used as plant food particles for the stabilization of O/W Pickering emulsion.

In this work, water-insoluble bamboo shoot dietary fiber (BSDF) was prepared, and used as plant food particle stabilizer for oil-in-water (O/W) Pickering emulsions. The obtained plant food particle had novel emulsification ability, the prepared emulsions were stable against coalescence for at least 4 weeks and also insensitive to pH, ionic strength and pasteurization conditions. The BSDF suspensions and BSDF-stabilized O/W emulsions both exhibited shear-thinning behaviors; moreover, both viscosity and module were increased with the increase of BSDF contents. The surface coverage of emulsions was positively correlated with the content of BSDF suspensions. It indicated that the dietary fibers from bamboo shoot had a soft nature and suitable shape to produce stable Pickering emulsions, which could be used as food-grade particles for applications of food and cosmetics industries.

Coagulation mechanism of cellulose/metal nanohybrids through a simple one-step process and their interaction with Cr (VI).

In this work, the coagulation mechanism of the cellulose/metal nanohybrids and the binding mode with Cr (VI) are deeply described. Nanohybrids with 3D porous networks were prepared from cellulose/Fe2O3-SO3H solutions through a simple one-step coagulation process in NaCl aqueous solutions. The structure and properties of nanohybrids were characterized by SEM, EDS, XRD, FTIR, and XPS. The cellulose/metal nanohybrids have a langmuir maximum adsorption capacity of 11.46 mg/g. The dissolved metal nanoparticles could form strong hydrogen bonding with cellulose by breaking the intermolecular hydrogen bonds between the polymer molecules. The porous networks of cellulose/metal nanohybrids provided multiple adsorption sites for Cr2O72- anion through FeO…Cr interactions. The cooperation between cellulose and Fe2O3-SO3H nanoparticles makes the hybrids exhibiting a satisfactory selectivity and affinity for Cr (VI). The cellulose/metal nanohybrids selectively interacted with Cr2O72- via Fe atom from Fe2O3 and oxygen atom from SO3- groups. The Cr (VI) adsorption occurred via a two-step process, the first of them was the initial adsorption of Cr2O72- on cellulose/metal nanohybrids surface, followed by the rearrangement of Cr2O72- molecules and the consecutive growth of Cr2O72- aggregate layers.

Highly efficient removal of amoxicillin from water by Mg-Al layered double hydroxide/cellulose nanocomposite beads synthesized through in-situ coprecipitation method.

Amoxicillin in the municipal water system needs to be removed due to the toxicity towards creatures. In this work, Mg-Al LDH/cellulose nanocomposite beads (LDH@CB) were synthesized by an in situ coprecipitation procedure and were used as novel adsorbents for amoxicillin removal in the aqueous phase. Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), The specific surface area test (BET), scanning electron microscopy (SEM), ζ potential, X-ray electron energy (XPS) were employed to confirm the success load of LDH onto CB. The large specific surface area (76.46 m2 g-1), high water content (92.05%) and high porosity (94.75%) of LDH@CB made the adsorbent suitable in water treatment. The adsorption process was kinetically fitted with the pseudo second-order kinetic model while isothermally fitted with the Freundlich isotherm model. It was found that the maximum adsorption capacity of LDH@CB qm was 138.3 mg g-1. Meanwhile, the results from XPS and ζ potentials revealed the AMX removal mechanism: Under natural pH conditions, AMX was negatively charged and LDH@CB was positively charged, the contaminant and the adsorbent were linked by electrostatic interaction through OCO⋯M (Mg/Al). These results showed that the adsorbent design method had a wide application prospect in the water purification field.

An easy and unique design strategy for insoluble humic acid/cellulose nanocomposite beads with highly enhanced adsorption performance of low concentration ciprofloxacin in water.

In this work, two plant wastes were reused to fabricate the homogeneous 3D micro-nano porous structured humic acid/cellulose nanocomposite beads (IHA@CB) embedded with insoluble humic acid (IHA) particles. The subtle synthesis method attributed to the homogenous distribution of IHA particles in the cellulose matrix and improved the adsorption performance of IHA@CB for low concentration ciprofloxacin in water. Physical and chemical properties of the beads were characterized by SEM, EDX, XRD, FTIR, and the adsorption process of ciprofloxacin was studied by isotherm, kinetic and dynamic adsorption experiments. The maximum adsorption capacity of IHA@CB on CPX reached 10.87 mg g-1 under 318 K. The dynamic experiments were conducted by adjusting bed height, flow rate, initial concentration and pH values, and the regeneration experiments proved the adsorbent exhibited good repeatability. The adsorption mechanism was revealed that CPX was adsorbed by IHA@CB mainly through cation exchange.

Edible coating based on beeswax-in-water Pickering emulsion stabilized by cellulose nanofibrils and carboxymethyl chitosan.

In this work, novel edible coating films based on beeswax-in-water (O/W) Pickering emulsions had been investigated. The Pickering emulsions were stabilized with cellulose nanofibrils (CNFs)/carboxymethyl chitosan (CCS). The emulsions with a droplet diameter of around 10 µm had uniform particle size distribution, and the creaming stability was improved with the increasing the contents of CNFs in the complexes, rheological analysis demonstrated that the Pickering emulsions had an elastic gel-like network. Furthermore, free-standing films were obtained when the emulsions were dried at ambient condition, the tensile strength of the coating films could be 5.0 MPa at a strain of 2.2%, and the water vapor permeability (WVP) value was lower than 2 × 10-7 g∙h-1∙m-1∙Pa-1. Moreover, the coating films could inhibit the growth of typical spoilage organisms such as S. aureus or E. coli, it indicated that the coatings films would have promising applications in antiseptic and fresh keeping for berry fruits.