Extraction of Glyoxylic Acid Stabilized Lignin from Lignocellulosic Biomass for a Natural Sunscreen Additive

Natural lignin has been considered a promising additive for ultraviolet (UV) protection cosmetics applications. Nevertheless, its potential application in cosmetics production is impeded by its inherent dark coloration due to structural damage incurred during the industrial lignin extraction process. In this study, glyoxylic acid (GA) was used to prevent lignin condensation during lignin extraction using an acid recycled hydrotrope (p-toluenesulfonic acid, p-TsOH). Further processing of the GA stabilized lignin yielded lignin nanospheres (LNPs) for a natural sunscreen additive. Incorporating 3% and 4% LNPs into a baseline SPF10 commercial sunscreen resulted in lignin-based sunscreen with SPF values of 37.2 ± 2.55 and 58.74 ± 2.14, respectively. These exceeded the SPF levels observed in commercial sunscreens with SPF30 and SPF50. Furthermore, the pretreated cellulose residue was utilized in the production of pulp fibers for papermaking. It was observed that the ring crush strength index of the paper, achieved by incorporating 15 wt % fibers into softwood pulp, reached a notable value of 2.98 ± 0.10 N·m/g. The tear index and tensile index of the produced paper, augmented with a 5 wt % addition of fibers, were as high as 4.77 ± 0.41 mN·m2/g and 9.49 ± 0.27 N·m/g, respectively. Therefore, a new strategy for stabilized lignin extraction and lignocellulose biomass valorization was proposed in this study

Microcrystalline Cellulose-Based Eraser

Eraser, the most widely used stationery item made of vulcanized rubbers or petroleum-based resins, is too common to draw attention. Its fragments falling off during the erasing process may appear small and insignificant; however, it should be noteworthy that they are in fact microplastics, which are hard to degrade in nature and pose significant threats to the ecological environment. In this work, a microcrystalline cellulose (MCC)-based elastomer was proposed that displays an impressive erasure effect combined with good biodegradability. This special erasure function is attributed to its unique microstructure, in which a very high loading of MCC (75 wt %) was achieved via a planetary centrifugal mixing of MCC and a polyethylene glycol-derived aqueous polyurethane (APE). Scanning electron microscopy (SEM) showed that MCC particles were uniformly coated with APE. Differential scanning calorimetry (DSC) and swelling tests further clarified the specific interactions between APE and MCC. The oriented aggregation principle and Young’s equation were employed to describe the erasure behavior and elucidate the underlying mechanism. It indicated that APE played a key role in transferring pencil lead powders from paper to the eraser. SEM, Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS) indicated that MCC played another key role in facilitating the removal of pencil shavings from the eraser’s surface. This work provides a feasible thought for fabricating an “eco-eraser” based on commercially available MCC, which shows great potential in reducing the harm of eraser microplastics on the ecological environment and develops a brand new application of cellulose in composite materials

Translucent and Anti-ultraviolet Aramid Nanofiber Films with Efficient Light Management Fabricated by Sol–Gel Transformation

Derived from poly­(para-phenylene terephthalamide) PPTA fibers, aramid nanofibers (ANFs) not only inherit the excellent properties of PPTA fibers but also demonstrate the nanoeffects of one-dimensional (1D) nanomaterials, showing great potentials in many emerging fields as building blocks. However, ANF-based materials are usually obtained by vacuum-assisted filtration after the regeneration of ANFs, leading to long cycle times and waste of energy. Moreover, the effects of antisolvents on the structure and property of the obtained ANF-based materials were rarely reported. In this work, an in situ-regenerated continuous production line of sol–gel transformation technology was provided to produce ANF films in a large scale. Moreover, the impacts of coagulation baths (water and ethanol) on the structure and properties of ANF films were investigated systematically. It was found that the coagulation baths had obvious effects on the microstructure and properties of ANF films. As a result, ANF films with high transparency, high anti-ultraviolet capacity, and tunable haze can be fabricated successfully by simply changing the component of the coagulation bath. Particularly, the averaged values of ANF films in the region of 315–400 nm (TUVA) and 290–315 nm (TUVB) are nearly 0%, and the haze of ANF Film 100 can reach as high as 90% at 800 nm when ethanol was used as the first coagulation bath. Meanwhile, ANF films (Film 0) regenerated from water displayed the highest transmittance (78.77% at 800 nm) and tensile strength (102.88 MPa), attributed to their homogeneous structures. Additionally, the transmittance and tensile strength were decreased obviously with the increasing ethanol content in the first coagulation bath. Overall, ANF films showed high tensile strength, good thermal stability, and fire-retardant performance. Herein, the ANF films with many merits demonstrate great promising potential to be used in the light management field

Microcrystalline Cellulose-Based Eraser

Eraser, the most widely used stationery item made of vulcanized rubbers or petroleum-based resins, is too common to draw attention. Its fragments falling off during the erasing process may appear small and insignificant; however, it should be noteworthy that they are in fact microplastics, which are hard to degrade in nature and pose significant threats to the ecological environment. In this work, a microcrystalline cellulose (MCC)-based elastomer was proposed that displays an impressive erasure effect combined with good biodegradability. This special erasure function is attributed to its unique microstructure, in which a very high loading of MCC (75 wt %) was achieved via a planetary centrifugal mixing of MCC and a polyethylene glycol-derived aqueous polyurethane (APE). Scanning electron microscopy (SEM) showed that MCC particles were uniformly coated with APE. Differential scanning calorimetry (DSC) and swelling tests further clarified the specific interactions between APE and MCC. The oriented aggregation principle and Young’s equation were employed to describe the erasure behavior and elucidate the underlying mechanism. It indicated that APE played a key role in transferring pencil lead powders from paper to the eraser. SEM, Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS) indicated that MCC played another key role in facilitating the removal of pencil shavings from the eraser’s surface. This work provides a feasible thought for fabricating an “eco-eraser” based on commercially available MCC, which shows great potential in reducing the harm of eraser microplastics on the ecological environment and develops a brand new application of cellulose in composite materials

Microcrystalline Cellulose-Based Eraser

Eraser, the most widely used stationery item made of vulcanized rubbers or petroleum-based resins, is too common to draw attention. Its fragments falling off during the erasing process may appear small and insignificant; however, it should be noteworthy that they are in fact microplastics, which are hard to degrade in nature and pose significant threats to the ecological environment. In this work, a microcrystalline cellulose (MCC)-based elastomer was proposed that displays an impressive erasure effect combined with good biodegradability. This special erasure function is attributed to its unique microstructure, in which a very high loading of MCC (75 wt %) was achieved via a planetary centrifugal mixing of MCC and a polyethylene glycol-derived aqueous polyurethane (APE). Scanning electron microscopy (SEM) showed that MCC particles were uniformly coated with APE. Differential scanning calorimetry (DSC) and swelling tests further clarified the specific interactions between APE and MCC. The oriented aggregation principle and Young’s equation were employed to describe the erasure behavior and elucidate the underlying mechanism. It indicated that APE played a key role in transferring pencil lead powders from paper to the eraser. SEM, Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS) indicated that MCC played another key role in facilitating the removal of pencil shavings from the eraser’s surface. This work provides a feasible thought for fabricating an “eco-eraser” based on commercially available MCC, which shows great potential in reducing the harm of eraser microplastics on the ecological environment and develops a brand new application of cellulose in composite materials

Microcrystalline Cellulose-Based Eraser

Eraser, the most widely used stationery item made of vulcanized rubbers or petroleum-based resins, is too common to draw attention. Its fragments falling off during the erasing process may appear small and insignificant; however, it should be noteworthy that they are in fact microplastics, which are hard to degrade in nature and pose significant threats to the ecological environment. In this work, a microcrystalline cellulose (MCC)-based elastomer was proposed that displays an impressive erasure effect combined with good biodegradability. This special erasure function is attributed to its unique microstructure, in which a very high loading of MCC (75 wt %) was achieved via a planetary centrifugal mixing of MCC and a polyethylene glycol-derived aqueous polyurethane (APE). Scanning electron microscopy (SEM) showed that MCC particles were uniformly coated with APE. Differential scanning calorimetry (DSC) and swelling tests further clarified the specific interactions between APE and MCC. The oriented aggregation principle and Young’s equation were employed to describe the erasure behavior and elucidate the underlying mechanism. It indicated that APE played a key role in transferring pencil lead powders from paper to the eraser. SEM, Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS) indicated that MCC played another key role in facilitating the removal of pencil shavings from the eraser’s surface. This work provides a feasible thought for fabricating an “eco-eraser” based on commercially available MCC, which shows great potential in reducing the harm of eraser microplastics on the ecological environment and develops a brand new application of cellulose in composite materials

Microcrystalline Cellulose-Based Eraser

Eraser, the most widely used stationery item made of vulcanized rubbers or petroleum-based resins, is too common to draw attention. Its fragments falling off during the erasing process may appear small and insignificant; however, it should be noteworthy that they are in fact microplastics, which are hard to degrade in nature and pose significant threats to the ecological environment. In this work, a microcrystalline cellulose (MCC)-based elastomer was proposed that displays an impressive erasure effect combined with good biodegradability. This special erasure function is attributed to its unique microstructure, in which a very high loading of MCC (75 wt %) was achieved via a planetary centrifugal mixing of MCC and a polyethylene glycol-derived aqueous polyurethane (APE). Scanning electron microscopy (SEM) showed that MCC particles were uniformly coated with APE. Differential scanning calorimetry (DSC) and swelling tests further clarified the specific interactions between APE and MCC. The oriented aggregation principle and Young’s equation were employed to describe the erasure behavior and elucidate the underlying mechanism. It indicated that APE played a key role in transferring pencil lead powders from paper to the eraser. SEM, Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS) indicated that MCC played another key role in facilitating the removal of pencil shavings from the eraser’s surface. This work provides a feasible thought for fabricating an “eco-eraser” based on commercially available MCC, which shows great potential in reducing the harm of eraser microplastics on the ecological environment and develops a brand new application of cellulose in composite materials

High-Level Production of Lacto‑<i>N</i>‑neotetraose in <i>Escherichia coli</i> by Stepwise Optimization of the Biosynthetic Pathway

Lacto-N-neotetraose (LNnT), an abundant human milk oligosaccharide (HMO), has been approved as a novel functional additive for infant formulas. Therefore, LNnT biosynthesis has attracted extensive attention. Here, a high LNnT-producing, low lacto-N-triose II (LNT II)-residue Escherichia coli strain was constructed. First, an initial LNnT-producing chassis strain was constructed by blocking lactose, UDP-N-acetylglucosamine, and UDP-galactose competitive consumption pathways and introducing β-1,3-N-acetylglucosaminyltransferase LgtA and β-1,4-galactosyltransferase LgtB. Subsequently, the supply of LNnT precursors was increased by enhancing UDP-N-acetylglucosamine and UDP-galactose synthesis, inactivating LNT II extracellular transporter SetA, and improving UTP synthesis. Then, modular engineering strategy was used to optimize LNnT biosynthetic pathway fluxes. Moreover, pathway fluxes were fine-tuned by modulating translation initiation strength of essential genes lgtB, prs, and lacY. Finally, LNnT production reached 6.70 g/L in a shake flask and 19.40 g/L in a 3 L bioreactor with 0.47 g/(L h) productivity, with 1.79 g/L LNT II residue, highest productivity level, and lowest LNT II residue thus far

Cancellous Bone-like Polyurethane Foam: A Porous Material with Excellent Properties for Ultra-high Energy Absorption

Compared to osteoporotic bone, normal cancellous bone exhibits greater resistance to impact and energy absorption. The Gibson–Ashby model of cellular structure reveals that the enhancement is attributed to a unique combination of the thick wall and small pores in porous materials. Inspired by this design concept, here, a cancellous bone-like PU foam was developed through the planetary centrifugal mixing (PCM) method. Different from previously reported high energy absorption materials, this porous material possesses a thick-wall (average thickness of 33 μm) and micropore (average size of less than 55 μm) morphology. The enlarged SEM image revealed the presence of nanoscale dispersed conductive carbon blacks embedded within the thick walls in a primary aggregate state. Furthermore, the Raman spectrometer provided additional insights into the interaction between carbon black and the PU matrix. This unique morphology was achieved by the dual actions of centrifugal and tangential forces exerted by PCM, whereby challenges in efficient mixing and dispersion of highly viscous material were successfully overcome. The unique microstructure endows the foam with ultra-high compressive strength (yield strength of 17.0 MPa) and energy absorption capacity (12.19 MJ/m3), which are comparable to polyimide foam (3.31 MJ/m3) and many lattice composite structures (5–14.07 MJ/m3) that are well known for their high energy absorption properties. In addition to the impressive energy absorption capacity, excellent comprehensive properties, such as antistatic property (an electrical conductivity of 0.346 S/m), a low thermal conductivity (0.0274 W/m·K), and fast heating responsiveness (increase by 40 °C within 180 s), are also obtained in this foam. In contrast to the complex and costly approaches in fabricating ultra-high energy absorption materials, this simple and cost-effective method opens up an attractive way in obtaining high energy absorption material with excellent comprehensive properties by a one-step PCM procedure

Cancellous Bone-like Polyurethane Foam: A Porous Material with Excellent Properties for Ultra-high Energy Absorption

Compared to osteoporotic bone, normal cancellous bone exhibits greater resistance to impact and energy absorption. The Gibson–Ashby model of cellular structure reveals that the enhancement is attributed to a unique combination of the thick wall and small pores in porous materials. Inspired by this design concept, here, a cancellous bone-like PU foam was developed through the planetary centrifugal mixing (PCM) method. Different from previously reported high energy absorption materials, this porous material possesses a thick-wall (average thickness of 33 μm) and micropore (average size of less than 55 μm) morphology. The enlarged SEM image revealed the presence of nanoscale dispersed conductive carbon blacks embedded within the thick walls in a primary aggregate state. Furthermore, the Raman spectrometer provided additional insights into the interaction between carbon black and the PU matrix. This unique morphology was achieved by the dual actions of centrifugal and tangential forces exerted by PCM, whereby challenges in efficient mixing and dispersion of highly viscous material were successfully overcome. The unique microstructure endows the foam with ultra-high compressive strength (yield strength of 17.0 MPa) and energy absorption capacity (12.19 MJ/m3), which are comparable to polyimide foam (3.31 MJ/m3) and many lattice composite structures (5–14.07 MJ/m3) that are well known for their high energy absorption properties. In addition to the impressive energy absorption capacity, excellent comprehensive properties, such as antistatic property (an electrical conductivity of 0.346 S/m), a low thermal conductivity (0.0274 W/m·K), and fast heating responsiveness (increase by 40 °C within 180 s), are also obtained in this foam. In contrast to the complex and costly approaches in fabricating ultra-high energy absorption materials, this simple and cost-effective method opens up an attractive way in obtaining high energy absorption material with excellent comprehensive properties by a one-step PCM procedure