Water-Resistant Poly(vinyl alcohol)/ZnO Nanopillar Composite Films for Antibacterial Packaging.

To solve the problems that poly(vinyl alcohol) (PVA) easily breeds bacteria and swells in a humid environment, PVA and ZnO nanopillar (ZnO NP) components were composed to generate PVA/ZnO NP composite films via a simple combination process of blending and heat treatment in this study. Here, ZnO NPs endowed composite films with good antibacterial properties, and the etherification and dehydration of hydroxyl groups between PVA molecular chains induced by heat treatment resulted in the composite films having excellent water-swelling resistance. Most importantly, PVA/ZnO NP composite films revealed excellent tensile strength in both humid (52.

Ultralight and highly efficient oil-water selective aerogel from carboxymethyl chitosan and oxidized β-cyclodextrin for marine oil spill cleanup.

Biomass-based aerogels for oil spill cleanup have attracted tremendous research interests due to their feasibility in oil-water separation. However, the cumbersome preparation process and toxic cross-linking agents hinder their application. In this work, a facile and novel method to prepare hydrophobic aerogels is reported for the first time.

Dual-functional lignin-based hydrogels for sustained release of agrochemicals and heavy metal ion complexation.

An effective way of improving the efficiency of agrochemicals and improving crop yield and quality is by slow or sustained release, which is conducive to environmental protection. Meanwhile, the excessive amount of heavy metal ions in soil can create toxicity in plants. Here, we prepared lignin-based dual-functional hydrogels containing conjugated agrochemical and heavy metal ligands through free-radical copolymerization.

Sugarcane cellulose-based composite hydrogel enhanced by g-CN nanosheet for selective removal of organic dyes from water.

The effective removal of toxic dyes from aqueous solution is of great significance for environmental protection. Herein, an eco-friendly sugarcane cellulose (SBC)/sodium carboxymethylcellulose (CMC-Na) adsorbent reinforced with carbon nitride (g-CN) was successfully prepared via a facile sol-gel method. The resulting gel-like adsorbent or composite hydrogel was comprehensively characterized with FTIR, SEM, EDS, TGA analysis.

Redox- and Enzyme-Responsive Macrospheres Gatekept by Polysaccharides for Controlled Release of Agrochemicals.

Stimuli-responsive materials afford researchers an opportunity to synthesize controlled-release carriers with various potential applications, especially for reducing the abuse of chemical reagents in farmland soil. To enhance the efficiency of agrochemical utilization, redox- and enzyme-responsive macrospheres were prepared by self-assembling β-cyclodextrin-modified zeolite and ferrocenecarboxylic acid (FcA)-grafted carboxymethyl cellulose (CMC). Scanning electron microscopy and Brunauer-Emmett-Teller analysis revealed that pores of zeolite were sealed by the surface coupling of FcA-modified CMC via the formation of an inclusion complex.

Cellulose-based antimicrobial films incroporated with ZnO nanopillars on surface as biodegradable and antimicrobial packaging.

Biodegradable and antimicrobial films without antibiotics are of great significance for the application associated with food packaging meanwhile minimizing the negative impact on environments. In this work, cellulose-based films with the surface tailor-constructed with ZnO nanopillars (ZnO NPs@Zn/Cel films) were prepared via chemical crosslinking in conjunction with a hydrothermal process for in-situ growth of ZnO NPs. As a packaging material, ZnO NPs@Zn/Cel films possess excellent mechanical properties, oxygen and water vapor barrier, food preservation, biodegradability and low Zn migration.

Novel multi-responsive and sugarcane bagasse cellulose-based nanogels for controllable release of doxorubicin hydrochloride.

Nanogel based on polysaccharides has attracted the tremendous interest due to its unique performance as drug carrier for in vivo release. In this work, the multi-responsive nanogels were developed based on the tailor-modified sugarcane bagasse cellulose (SBC). In the presence of crosslinking agent cystamine bisacrylamide (CBA), the in-situ free radical copolymerization of methacrylated monocarboxylic sugarcane bagasse cellulose (MAMC-SBC) and N-isopropylacrylamide (NIPAM) in aqueous phase was conducted, thus leading to redox, pH and thermal-responsive nanogels.

Functionalized porous magnetic cellulose/FeO beads prepared from ionic liquid for removal of dyes from aqueous solution.

Porous magnetic cellulose/FeO beads (CFBs), consisting of cellulose as matrix and ferrosoferric oxide, were successfully fabricated from microcrystalline cellulose dissolved in an ionic liquid and further modified with glutaric anhydride. The porous structure of modified magnetic cellulose/FeO beads (MCFBs) was created by nano-sized calcium carbonate (CaCO). The resulting MCFBs were well characterized and employed as effective adsorbents for removal of dyes from aqueous solution.

Cellulose-based adsorbents loaded with zero-valent iron for removal of metal ions from contaminated water.

Sawdust loaded with zero-valent iron (S-ZVI) was prepared using a liquid phase reduction method for removing heavy metal ions from contaminated water. Surface chemistry and morphology of adsorbents were characterized with Fourier transform infrared (FT-IR) spectrometry, X-ray diffraction (XRD), scanning electron microscopy (SEM), SEM-mapping, EDX, and X-ray photoelectron spectrum (XPS). The results demonstrated that the zero-valent iron was successfully loaded onto the sawdust.

Dual-Functional Redox-Responsive Nanocarriers for Loading Phytohormone and Complexation with Heavy Metal Ions.

This work focused on designing a novel redox-responsive nanocarrier synthesized from carboxymethyl-β-cyclodextrin-modified nanosilica, which could load and release plant hormones, such as salicylic acid (SA), in plant cells. When the SA-loaded nanoparticles cross the plant cell wall, the disulfide bond can be broken to form sulfhydryl groups under the action of reduced glutathione (GSH), thus releasing SA. Meanwhile, the resulting thiol groups exhibited strong affinity toward several heavy metal ions, mercury ions in particular, thus playing a role similar to phytochelatins for detoxification.

Hydrothermal synthesis of nitrogen-doped ordered mesoporous carbon lysine-assisted self-assembly for efficient CO capture.

Nitrogen-doped ordered mesoporous carbons (NOMCs) were synthesized by single-step hydrothermal self-assembly using F127 as a soft template, hexamine as a formaldehyde source, l-lysine as a polymerization catalyst, and 3-aminophenol as both carbon and nitrogen sources. The microstructure of the NOMCs was characterized by XRD, N adsorption/desorption, TEM, FTIR, and XPS. The results indicated that the obtained NOMCs exhibited a large specific surface area, uniform pore size distribution and highly ordered 2-D hexagonal mesostructure (6).

Green-Based Antimicrobial Hydrogels Prepared from Bagasse Cellulose as 3D-Scaffolds for Wound Dressing.

Developing the ideal biomaterials for wound dressing still remains challenging nowadays due to the non-biodegradable features and the lack of antimicrobial activity of conventional synthetic polymer-based dressing materials. To tackle those problems, a novel and green-based antimicrobial hydrogel dressing was synthesized in this work via modifying sugarcane bagasse cellulose with guanidine-based polymer, followed by crosslinking antimicrobial-modified cellulose with unmodified one at various ratios. The resulting hydrogels were comprehensively characterized with swelling measurements, compression test, Fourier transform infrared spectroscopy, and scanning electron microscopy.

Cationic Polymers with Tailored Structures for Rendering Polysaccharide-Based Materials Antimicrobial: An Overview.

Antimicrobial polymers have attracted substantial interest due to high demands on improving the health of human beings via reducing the infection caused by various bacteria. The review presented herein focuses on rendering polysaccharides, mainly cellulosic-based materials and starch to some extent, antimicrobial via incorporating cationic polymers, guanidine-based types in particular. Extensive review on synthetic antimicrobial materials or plastic/textile has been given in the past.

Thermal and pH dual-responsive cellulose microfilament spheres for dye removal in single and binary systems.

Cellulose microfilaments/poly(N-Isopropylacrylamide-co-acrylic acid) spheres (MPNAA) were prepared via the in-situ synthesis of semi-interpenetrating networks (semi-IPN). The free radical copolymerization of acrylic acid (AA) (for pH-sensitive chain segments) and N-isopropylacrylamide (NIPAM) (for temperature-sensitive chain segments) was conducted in a microwave-reactor in the presence of porous cellulose/microfilament composite spherical beads pre-prepared. The surface morphology and adsorption properties of the as-prepared spheres were systematically characterized.

Controlled Release of Agrochemicals Using pH and Redox Dual-Responsive Cellulose Nanogels.

A novel pH and redox dual-responsive cellulose-based nanogel was prepared for the controlled release of agrochemicals. To synthesize the responsive nanogel, palmitoyl chloride and glyoxal were modified on carboxymethyl cellulose sequentially and 3,3'-dithiobis(propionohydrazide) was used as a cross-linker to assemble the nanogel. The morphology, structure, and physical properties of nanogels were characterized with transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), particle size analysis, and zeta-potential measurement.

Novel cellulose/montmorillonite mesoporous composite beads for dye removal in single and binary systems.

Fine aminated cellulose/montmorillonite mesoporous composite beads (ACeMt) were prepared as green-based adsorbent via a novel approach utilizing ultra-fine calcium carbonate as a pore-forming agent to increase the porosity and specific surface area of ACeMt. The resulting bioadsorbent was characterized by means of SEM, FTIR and BET analysis and used for dye removal. Adsorption experimental data were fitted with various isotherm and kinetic models.

Controlled release of agrochemicals and heavy metal ion capture dual-functional redox-responsive hydrogel for soil remediation.

Novel redox-responsive hydrogels were prepared based on disulfide-crosslinked carboxymethyl cellulose for the controlled-release of agrochemicals. After release, the reduced hydrogels could capture heavy metal ions in soil via strong complexation between the ions and thiol groups generated by disconnected disulfide bonds, thus benefiting plant growth and soil remediation synchronously.

Adsorption of Hg (II) ions from aqueous solution by diethylenetriaminepentaacetic acid-modified cellulose.

The diethylenetriaminepentaacetic acid (DTPA)-modified cellulose adsorbent was prepared using N‑[3‑(trimethoxysilyl)propyl]ethylenediamine as a crosslinking reagent and used for the removal of Hg (II) ions from aqueous solution. The resulting adsorbents were comprehensively characterized with FTIR, XRD and SEM. The results showed that DTPA successfully functionalized cellulose, and coordinating DTPA ligand improved the binding properties towards heavy metal ions significantly.

Study on cellulose microfilaments based composite spheres: Microwave-assisted synthesis, characterization, and application in pollutant removal.

A novel study of synthesizing the temperature-responsive polymer grafted cellulose filaments/Poly (N-isopropylacrylamide) (NIPAM) spheres (P-MCCBs) was carried out for the removal of dyes and heavy metal ions. The novelty of the presented work consists of the application of the nano-sized pore-forming agent (Calcium Carbonate) and the introduction of a temperature-responsive monomer (NIPAM) while preparing the adsorbents. In addition, the spherical adsorbents were synthesized through an in-situ free radical polymerization using a microwave-assisted heating approach.

Dual-responsive IPN hydrogel based on sugarcane bagasse cellulose as drug carrier.

In this work, the stepwise synthesis of interpenetrating polymer network (IPN) strategy was developed in an attempt to fabricate novel hydrogels consisting of sugarcane bagasse cellulose (SBC), carboxymethylcellulose (CMC) and poly (N-isopropylacrylamide) (PNIPAm) as a dual-responsive drug carrier. The pretreated and dissolved SBC was pre-crosslinked using epichlorohydrin in the presence of CMC, followed by in-situ free-radical polymerization of NIPAm in the presence of N,N'-Methylene-bis(acrylamide) as a crosslinking agent. The carboxyl groups in CMC and PNIPAm chains rendered the resulting hydrogel pH and thermal responsive.

Microrheology, advances in methods and insights.

Microrheology is an emerging technique that probes mechanical response of soft material at micro-scale. Generally, microrheology technique can be divided into active and passive versions. During last two decades, extensive efforts have been paid to improve both the experiment techniques and data analysis methods, especially about how to link consequential particle positions into trajectories.

Preparation of Copolymer-Based Nanoparticles with Broad-Spectrum Antimicrobial Activity.

Polyacrylate and guanidine-based nanoparticles which involve acrylate monomers and glycidyl methacrylate modified oligo-guanidine were prepared by a seeded semi-continuous emulsion polymerization. The results from transmission electron microscope and dynamic light scattering measurements showed that the nanoparticles were spherical in shape and the particle size was in the range of 80⁻130 nm. Antimicrobial experiments were performed with two types of bacteria, Gram-negative (, ATCC 8739) and Gram-positive (, ATCC 6538).

Single and binary adsorption of heavy metal ions from aqueous solutions using sugarcane cellulose-based adsorbent.

A high efficient and eco-friendly sugarcane cellulose-based adsorbent was prepared in an attempt to remove Pb, Cu and Zn from aqueous solutions. The effects of initial concentration of heavy metal ions and temperature on the adsorption capacity of the bioadsorbent were investigated. The adsorption isotherms showed that the adsorption of Pb, Cu and Zn followed the Langmuir model and the maximum adsorptions were as high as 558.

Preparation and Characterization of Epoxy Resin Cross-Linked with High Wood Pyrolysis Bio-Oil Substitution by Acetone Pretreatment.

The use of cost effective solvents may be necessary to store wood pyrolysis bio-oil in order to stabilize and control its viscosity, but this part of the production system has not been explored. Conversely, any rise in viscosity during storage, that would occur without a solvent, will add variance to the production system and render it cost ineffective. The purpose of this study was to modify bio-oil with a common solvent and then react the bio-oil with an epoxy for bonding of wood without any loss in properties.