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A type of zwitterionic chitosan derivative, N-2-hydroxylpropyl-3-trimethylammonium-O-carboxymethyl chitosan (HTCMCh), was synthesized and introduced into carboxymethyl cellulose (CMC)-based films as a film strength enhancer and antibacterial agent. The influencing factors include degree of substitution (DS) and mHTCMCh/mCMC. Their influences on mechanical properties, thermal stability, antibacterial activities, microstructures, transmittance, and wettability of the CMC-based films were studied. It was found that HTCMCh improves the tensile strength (by 9.0-130.9%), Young's modulus (47.8-351.6%), and elongation at break (90.8-280.8%) of CMC/HTCMCh films simultaneously, depending on the DS and mass content of HTCMCh. However, the HTCMCh shows little influence on microstructure and thermal stability of CMC/HTCMCh films. Satisfactorily, CMC/HTCMCh films show strong antibacterial activities against E. coli and S. aureus and are nontoxic to fibroblast HFF-1 cells. Pork packaging experiments demonstrated that CMC/HTCMCh10%,0,58 film could significantly inhibit bacterial growth, indicating that the HTCMCh-doped CMC films could be used as food packaging materials.

An efficient separation technology for hydrolysates towards a full valorization of bamboo is still a tough challenge, especially regarding the lignin and lignin-carbohydrate complexes (LCCs). The present study aimed to develop a facile approach using organic solvent extraction for efficiently fractionating the main components of bamboo hydrolysates. The high-purity lignin with only a trace of carbohydrates was first obtained by precipitation of the bamboo hydrolysate. The water-soluble lignin (WSL) fraction was extracted in organic solvent through a three-stage organic solvent extraction process, and the hemicellulosic sugars with increased purity were also collected. Furthermore, a thorough characterization including various NMR techniques (31P, 13C, and 2D-HSQC), GPC, and GC-MS was conducted to the obtained lignin-rich-fractions. It was found that the WSL fraction contained abundant functional groups and tremendous amount of LCC structures. As compared to native LCC of bamboo, the WSL fraction exhibited more typical LCC linkages, i.e. phenyl glycoside linkage, which is the main type of chemical linkage between lignin and carbohydrate in both LCC samples. The results demonstrate that organic phase extraction is a highly efficient protocol for the fractionation of hydrolysate and the isolation of LCC-rich streams possessing great potential applications.

Lignin, as the most abundant aromatic biopolymer in nature, has attracted great attention due to the complexity and richness of its functional groups for value-added applications. The yield of production of lignin and the reactivity of prepared lignin are very important to guarantee the study and development of lignin-based chemicals and materials. Various fractionation techniques have been developed to obtain high yield and relatively high-purity lignin as well as carbohydrates (hemicelluloses and celluloses) and to reduce the condensed and degraded nature of conventional biorefinery lignin. Herein, novel and efficient biomass fractionation and lignin fractionation towards lignin valorization are summarized and discussed.

Lignin, as the most abundant aromatic renewable biopolymer in nature, has long been regarded as waste and simply discarded from the pulp and paper industry. In recent years, with many breakthroughs in lignin chemistry, pretreatment, and processing techniques, a lot of the inherent bioactivities of lignin, including antioxidant activities, antimicrobial activities, biocompatibilities, optical properties, and metal-ion chelating and redox activities, have been discovered and this has opened a new field not only for lignin-based materials but also for biomaterials. In this Review, the biological activities of lignin and drug/gene delivery and bioimaging applications of various types of lignin-based material are summarized. In addition, the challenges and limitations of lignin-based materials encountered during the development of biomedical applications are also discussed.

Biodegradable and renewable materials, such as cellulose nanomaterials, have been studied as a replacement material for traditional plastics in the biomedical field. Furthermore, in chronic wound care, modern wound dressings, hydrogels, and active synthetic extracellular matrices promoting tissue regeneration are developed to guide cell growth and differentiation. Cells are guided not only by chemical cues but also through their interaction with the surrounding substrate and its physicochemical properties. Hence, the current work investigated plant-based cellulose nanomaterials and their surface characteristic effects on human dermal fibroblast (HDF) behavior. Four thin cellulose nanomaterial-based coatings produced from microfibrillar cellulose (MFC), cellulose nanocrystals (CNC), and two TEMPO-oxidized cellulose nanofibers (CNF) with different total surface charge were characterized, and HDF viability and adhesion were evaluated. The highest viability and most stable adhesion were on the anionic CNF coating with a surface charge of 1.14 mmol/g. On MFC and CNC coated surfaces, HDFs sedimented but were unable to anchor to the substrate, leading to low viability.

N-2-hydroxylpropyl-3-trimethylammonium-O-carboxymethyl chitosan (HTCMCh) was synthesized through homogeneous reaction. The effects of different reaction condition on the properties of HTCMCh were characterized by FTIR, NMR, SEM, TEM, DLS, XRD, TGA, and DSC. The results of FTIR spectra, 1H NMR, and 13C NMR proved the successful synthesis of HTCMCh. The DS was dependent upon reaction time and pretreated pH of the starting material, independent of temperature and nepoxy/n-NH2. With increasing reaction time, the crystallinity of HTCMCh decreased, and the intermolecular interactions transformed from hydrogen bonding to strong electrostatic interactions, which enhanced HTCMCh thermal stability. SEM observations showed smooth cross section morphologies of HTCMCh films. With the increase in reaction time, the tensile strength significantly increased. The viscoelasticity transformed from viscous to elastic with aging time, confirming the formation of polyelectrolyte complexes. The optimum reaction conditions: reaction time of 2 h, an initial material pH of 9.47, nepoxy/n-NH2 of 2/1.

Electrically conductive composite nanofibers were fabricated using poly(3,4-ethylenedioxythiophene) doped with poly(styrenesulfonate) (PEDOT-PSS) and cellulose nanofibrils (CNFs) via the electrospinning technique. Poly(ethylene oxide) (PEO) was used to assist the electrospinning process, and poly(ethylene glycol) diglycidyl ether was used to induce chemical cross-linking, enabling stability of the formed fibrous mats in water. The experimental parameters regarding the electrospinning polymer dispersion and electrospinning process were carefully studied to achieve a reproducible method to obtain bead-free nanofibrous mats with high stability after water contact, with an electrical conductivity of 13 ± 5 S m

To illuminate the interactions in N-[(2-hydroxyl)-propyl-3-trimethyl ammonium] chitosan chloride (HTCC)/sodium carboxymethyl cellulose (CMC) based films, the film-forming solutions were studied by rheology, and HTCC/CMC based films were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy and thermogravimetric analysis. The HTCC/CMC based film-forming solutions with glycerol (polyvinyl alcohol (PVA) and anthocyanin) showed shear-thinning behavior. The apparent viscosity of the HTCC/CMC/glycerol (PVA and anthocyanin) film-forming solutions decreased slower than that of HTCC/CMC film-forming solution, due to the electrostatic interaction between HTCC and CMC, and hydrogen bonding interaction between the two biomacromolecules and glycerol, PVA and anthocyanin, which resulted in the formation of three-dimensional networks. The anthocyanin with rigid molecular structure formed different three-dimensional matrix with HTCC/CMC, resulted in viscosity dominated film-forming solution. The pH affected the electrostatic interaction between HTCC, CMC, and anthocyanin through neutralizing –COO− groups, and temperature showed a synergistic effect on both electrostatic interaction and hydrogen bonding. The inter-molecular interactions resulted in the red-shift of typical absorption peaks, and the increase of initial decomposition temperature and decomposition enthalpy of HTCC/CMC based films. The homogenous and smooth surface, and the compact texture of HTCC/CMC based films confirmed the intermolecular interaction between HTCC, CMC, and PVA (glycerol and anthocyanin). Interactions in N-[(2-hydroxyl)-propyl-3-trimethyl ammonium] chitosan chloride and sodium carboxymethyl cellulose based films The HTCC/CMC/glycerol (PVA, anthocyanin) blend solutions show shear-thinning behavior, and the strong interaction between the molecules resists the decrease of viscosity.

Heavy metals have raised an increasing number of pollution incidents and resulted in potent damages to aquatic ecosystems and human health. Thus, effective and efficient approaches to eliminate heavy metal ions are in urgent needs. Herein, novel hybrid nanoparticles have been prepared by a facile method using epichlorohydrin as a cross-linker between amino-functionalized magnetic nanoparticles and carboxymethylated lignin. Multiple characterization methods including XRD, FTIR, XPS, SEM, and TEM confirmed the formed nanostructures and the chemical features of the lignin-based hybrid nanoparticles. The as-synthesized hybrid nanoparticles exhibited high adsorption capacities of 150.33 and 70.69 mg/g for Pb2+ and Cu2+, respectively. More importantly, the adsorption equilibriums of Pb2+ and Cu2+ onto hybrid nanoparticles can be achieved within 30 s, which are among the fastest functional adsorbents for Pb2+ and Cu2+ removal as reported by now. The ultrafast adsorption is ascribed not only to the nanostructures, but also to the abundant active sites provided by the carboxymethylated lignin. The mechanism of removing Pb2+ and Cu2+ by hybrid nanoparticles could be mainly attributed to ion exchange and hydrogen bonding. The tailored nanostructured hybrid nanoparticles with exceptional adsorption effectiveness and efficiency are low-cost and eco-friendly, which potentially meets the cost-effective criteria for producing the water treatment adsorbents on a large scale.

Owing to their superior mechanical strength and structure similarity to the extracellular matrix, nanocelluloses as a class of emerging biomaterials have attracted great attention in three-dimensional (3D) bioprinting to fabricate various tissue mimics. Yet, when printing complex geometries, the desired ink performance in terms of shape fidelity and object resolution demands a wide catalogue of tunability on the material property. This paper describes surface engineered biomimetic inks based on cellulose nanofibrils (CNFs) and cross-linkable hemicellulose derivatives for UV-aided extrusion printing, being inspired by the biomimetic aspect of intrinsic affinity of heteropolysaccharides to cellulose in providing the ultrastrong but flexible plant cell wall structure. A facile aqueous-based approach was established for the synthesis of a series of UV cross-linkable galactoglucomannan methacrylates (GGMMAs) with tunable substitution degrees. The rapid gelation window of the formulated inks facilitates the utilization of these wood-based biopolymers as the feeding ink for extrusion-based 3D printing. Most importantly, a wide and tunable spectrum ranging from 2.5 to 22.5 kPa of different hydrogels with different mechanical properties could be achieved by varying the substitution degree in GGMMA and the compositional ratio between GGMMA and CNFs. Used as the seeding matrices in the cultures of human dermal fibroblasts and pancreatic tumor cells, the scaffolds printed with the CNF/GGMMA inks showed great cytocompatibility as well as supported the matrix adhesion and proliferative behaviors of the studied cell lines. As a new family of 3D printing feedstock materials, the CNF/GGMMA ink will broaden the map of bioinks, which potentially meets the requirements for a variety of in vitro cell-matrix and cell-cell interaction studies in the context of tissue engineering, cancer cell research, and high-throughput drug screening.

To achieve full utilization of lignocellulosic biomass and easy integration of nanomaterials production, it is essential to develop an efficient fractionation to overcome the highly recalcitrant nature of lignocellulose and facilitate the subsequent valuable conversion. Herein, in a combined process based on the formic acid rapid fractionation of bamboo chips, pure cellulose, and lignin were first obtained as fractionated streams. Compared to wood kraft pulp, the bamboo-originated cellulose was easily converted into cellulose nanocrystals (CNCs) using TEMPO oxidation in a relatively short time, which holds greater potential to meet the commercial cost target. The dissolved lignin was processed into nanoparticles (lignin NPs), which exhibited spherical morphology and a uniform particle size distribution. Dispersions of CNCs and lignin NPs were prepared and further filtrated to form nanocomposite membranes. The nanocomposite membranes exhibited a very smooth surface and homogeneous structure. Most impressiv...

Hot-water extraction has shown great potential in a green biorefinery; however, efficient separation of lignin and carbohydrates is still a big challenge, especially to lignin–carbohydrate complexes (LCCs). The aim of the present study was to develop a facile approach for efficiently fractionating LCCs from hot-water extraction liquor of spruce wood to understand their comprehensive structure and thus to achieve the valorization of fractions. Approximately 93% of the hemicelluloses were first recovered by a selective adsorptive resin from hot-water hydrolysates. The lignin-rich fractions obtained from desorption of the adsorbed compounds were further subjected to a gradient dialysis procedure toward functional fractionation. Linear relationship between lignin and uronic acids as well as xylose contents in graded fractions of all hydrolysates was observed. Further characterization of LCCs by two-dimensional nuclear magnetic resonance and pyrolysis-gas chromatography-mass spectrometry showed the large diffe...

Lignin is the richest source of renewable aromatics and has immense potential for replacing synthetic chemicals. The limited functionality of lignin is, however, challenging for its potential use, which motivates research for creating advanced functional lignin-derived materials. Here, we present an aqueous-based acid precipitation method for preparing functional lignin nanoparticles (LNPs) from carboxymethylated or carboxypentylated lignin. We observe that the longer grafted side chains of carboxypentylated lignin allow for the formation of larger LNPs. The functional nanoparticles have high tolerance against salt and aging time and well-controlled size distribution with Rh ≤ 60 nm over a pH range of 5-11. We further investigate the layer-by-layer (LbL) assembly of the LNPs and poly(allylamine hydrochloride) (PAH) using a stagnation point adsorption reflectometry (SPAR) and quartz crystal microbalance with dissipation (QCM-D). Results demonstrate that LNPs made of carboxypentylated lignin (i.e., PLNPs with the adsorbed mass of 3.02 mg/m2) form a more packed and thicker adlayer onto the PAH surface compared to those made of carboxymethylated lignin (i.e., CLNPs with the adsorbed mass of 2.51 mg/m2). The theoretical flux, J, and initial rate of adsorption, (dΓ/dt)0, analyses confirm that 22% of PLNPs and 20% of CLNPs arriving at the PAH surface are adsorbed. The present study provides a feasible platform for engineering LNPs with a tunable size and adsorption behavior, which can be adapted in bionanomaterial production.

Hydrogels with ion exchange properties were synthesized from compounds derived from wood biopolymer hemicellulose and from commercial vinyl monomers to be tested as active materials for the removal of Cu(II), Cr(VI), and As(V) ions. The hemicellulose O-acetyl galactoglucomannan (GGM) was used as the precursor material, and through a transesterification reaction, GGM was converted into a macromonomer GGM–glycidyl methacrylate (GGM-GMA). Subsequently, the GGM-GMA macromonomer, containing more than one methacrylate group, was used as a crosslinking agent in the synthesis of hydrogels through free-radical polymerization reactions in combination with a 2-acrylamido-2-methyl-1-propanesulfonic acid monomer to produce a cation exchange hydrogel. Also, (3-acrylamidopropyl)trimethylammonium chloride monomer was applied together with the GGM-GMA to form hydrogels that can be used as anion exchange hydrogel. The hydrogels were characterized by Fourier transform-infrared (FT-IR), 1H-NMR spectroscopy, and thermogravimetric analysis (TGA), as well as derivative thermogravimetry (DTG). The microstructure of the hydrogels was characterized by scanning electron microscopy (SEM) analysis with X-ray microanalysis energy-dispersive spectroscopy (EDS). The results obtained regarding the absorption capacity of the Cu(II), Cr(VI), and As(V) ions were studied as a function of the pH value and the initial concentration of the metal ions in the solutions. Absorption was carried out in consecutive batches, and it was found that the poly(GGM-GMA/AMPSH) hydrogel reached an absorption capacity of 90 mg g–1 for Cu(II). The poly(GGM-GMA/APTACl) hydrogel reached values of 69 and 60 mg g–1 for Cr(VI) and As(V) oxyanions, respectively. Tests with polymer blends (mixtures of anionic and cationic hydrogels) were also carried out to remove Cu(II), Cr(VI), and As(V) ions from multi-ionic solutions, obtaining satisfactory results.

In this work we present a green method to prepare aerogel membranes based on cellulose nanofibers (CNFs) crossed-linked with poly (ethylene imine) (PEI) and further decorated with silver nanoparticles (Ag NPs). The nanosized Ag NPs were reduced and immobilized on the surface of the pore walls inside the aerogel. The as-prepared composite aerogel membrane showed excellent continuous catalytic discoloration of aqueous cationic and anionic dye solutions in batch and flow filtration tests. Moreover, the aerogel membrane exhibited very stable catalytic activity with discoloration efficiency at as high as 98% after 10 times reuse and the water permeance was high, up to 5 × 10 4 L·m −2 h −1. Interestingly, the aerogel membrane showed excellent shape recovery in water and no obvious deterioration of the structure was observed during long time testing. Therefore, the obtained aerogel membranes showed great potential in waste water treatment and catalytic applications.

Nanocelluloses have emerged as a catalogue of renewable nanomaterials for bioink formulation in service of 3D bioprinting, thanks to their structural similarity to extracellular matrices and excellent biocompatibility of supporting crucial cellular activities. From a material scientist’s viewpoint, this mini-review presents the key research aspects of the development of the nanocellulose-based bioinks in 3D (bio)printing. The nanomaterial properties of various types of nanocelluloses, including bacterial nanocellulose, cellulose nanofibers, and cellulose nanocrystals, are reviewed with respect to their origins and preparation methods. Different cross-linking strategies to integrate into multicomponent nanocellulose-based bioinks are discussed in terms of regulating ink fidelity in direct ink writing as well as tuning the mechanical stiffness as a bioactive cue in the printed hydrogel construct. Furthermore, the impact of surface charge and functional groups on nanocellulose surface on the crucial cellular activities (e.g., cell survival, attachment, and proliferation) is discussed with the cell–matrix interactions in focus. Aiming at a sustainable and cost-effective alternative for end-users in biomedical and pharmaceutical fields, challenging aspects such as biodegradability and potential nanotoxicity of nanocelluloses call for more fundamental comprehension of the cell–matrix interactions and further validation in in vivo models.

Nanocellulose is a material of interest for biomedical applications due to its morphological similarity with tissues’ own collagen. New cell culture substrates that mimic the human body tissue stiffness and extracellular matrix can be used to study cell behaviour in a way that is not possible for traditional plastic substrates. Five wood-based micro-and nanofibrillated cellulose films without additives were prepared to investigate the effects of nanocellulose charge density and fibril size on the mechanical properties of the films in liquids. Swelling behaviour of the films was studied in deionized water, in complete cell culture media (DMEM) and in CaCl2 solutions. Atomic force microscopy with a colloidal probe was used to measure Young’s modulus at the surface of the thin films submerged in the liquids. Cell culture media and CaCl2 solutions reduced the swelling of the films observed in deionized water, most probably due to a bridging effect by the calcium ions. The reduction was proportional to the charge of the particular nanocellulose. Young’s modulus in compression varied randomly on sample surfaces and appeared not to be directly related to topography of the films. In complete DMEM, the average Young’s modulus varied from 0.8 to 36.4 kPa, in the same stiffness range as two skin tissue layers, dermis and epidermis. Therefore, from mechanical properties point of view, these films seem suitable as cell culture substrates for skin tissue cells and could be used in skin tissue engineering.

Accurate determination of the distribution of substitutions in the primary molecular structure of heteropolysaccharides and their derivatives is a prerequisite for their increasing application in the pharmaceutical and biomedical fields, which is unfortunately hindered due to the lack of effective analytical techniques. Acetylated galactoglucomannan (GGM) is an abundant plant polysaccharide as the main hemicellulose in softwoods, and therefore constitutes an important renewable resource from lignocellulosic biomass for the development of bioactive and functional materials. Here we present a methodology for profiling the intramolecular structure of spruce GGM and its chemical derivatives (cationic, anionic, and benzoylated) by combining chemo-enzymatic hydrolysis, liquid chromatography, and mass spectrometry. Fast identification and qualitative mass profiling of GGM and its derivatives was conducted using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-ToF-MS) and electrospray ionization mass spectrometry (ESI-MS). Tandem mass fragmentation analysis and its hyphenation with hydrophilic interaction liquid chromatography (HILIC-ESI-MS/MS) provide further insights on the substitution placement of the GGM oligosaccharides and its derivatives. This method will be useful in understanding the structure-function relationships of native GGM and their derivatives, and therefore facilitate their potential application.

To promote the efficient utilization of lignocellulosic materials, one-step fractionation by formic acid-based organosolv process under pressure has been studied for converting lignocellulose in its main components. Lignin and hemicelluloses were selectively dissolved, while cellulose was not obviously degraded. Under optimized conditions (85% formic acid, a liquor-to-solid ratio of 7:1, and a temperature of 145°C for 45 min), this process provided a high efficient way to separate the main components of bamboo, obtaining 42.2% cellulose pulp, 31.5% lignin, 8.5% hemicellulose-rich fraction, 3.56% furfural and 3.80% acetic acid. Cellulose pulp with satisfying viscosity could easily be bleached to a high brightness of over 87% ISO with a short bleaching sequence, and had an acceptable paper strength properties. The recovered lignin fraction contained a small amount of carbohydrates and a considerable part of proteins and p-hydroxycinnamates. Additionally, the organic substances in hemicellulose-rich fraction...

Hypothesis: Amphiphilic character of surfactants drives them at the interface of dispersed systems, such as emulsions. Hemicellulose-rich wood extracts contain assemblies (lignin-carbohydrate complexes, LCC) with natural amphiphilicity, which is expected to depend on their chemical composition resulting from the isolation method. Lignin-derived phenolic residues associated with hemicelluloses are hypothesized to contribute to emulsions' interfacial properties and stability. Experiments: We investigated the role of phenolic residues in spruce hemicellulose extracts in the stabilization of oil-in-water emulsions by physical and chemical approach. Distribution and changes occurring in the phenolic residues at the droplet interface and in the continuous phase were studied during an accelerated storage test. Meanwhile, the physical stability and lipid oxidation in emulsions were monitored. Findings: Naturally associated lignin residues in GGM act as vehicles for anchoring these hemicelluloses into the oil droplet interface and further enable superior stabilization of emulsions. By adjusting the isolation method of GGM regarding their phenolic profile, their functionalities, especially interfacial behavior, can be altered. Retaining the native interactions of GGM and phenolic residues is suggested for efficient physical stabilization and extended protection against lipid oxidation. The results can be widely applied as guidelines in tailoring natural or synthetic amphiphilic compounds for interfacial stabilization. (C) 2017 Elsevier Inc. All rights reserved.

High purity (>99.5%) NaCMC solution was heated in ion-exchanged water and in an aqueous 10 mM NaHCO 3 buffer solution and studied as a function of time and temperature. The effects of thermal treatment on viscosity, pH, molecular weight and cationic demand of the solutions were measured. It was found that the anionic groups of carboxymethylcellulose are relatively stable against thermally induced degradation, but a reduction in NaCMC chain length and viscosity was observed. Only the highest applied temperature (177 °C), especially without any pH control, destroyed the side groups of the NaCMC. This was observed as a decrease in cationic demand and in the formation of glycolic acid. The application of buffer was noticed to retard the degradation of side groups. The observed decrease in viscosity with increasing reaction time in the presence of air was relatively well described by a second order reaction.

We present for the first time approaches to 3D-printing of nanocellulose hydrogel scaffolds based on double crosslinking, first by in situ Ca2+ crosslinking and post-printing by chemical crosslinking with 1,4-butanediol diglycidyl ether (BDDE). Scaffolds were successfully printed from 1% nanocellulose hydrogels, with their mechanical strength being tunable in the range of 3 to 8 kPa. Cell tests suggest that the 3D-printed and BDDE-crosslinked nanocellulose hydrogel scaffolds supported fibroblast cells' proliferation, which was improving with increasing rigidity. These 3D-printed scaffolds render nanocellulose a new member of the family of promising support structures for crucial cellular processes during wound healing, regeneration and tissue repair.

Bamboo was fractionated using formic acid based on a one-step organosolv process under high pressure (at 145 °C for 45 min, 0.3 MPa) and at atmospheric pressure (at 101 °C for 120 min), respectively. High-pressure formic acid lignin, atmospheric formic acid lignin and milled wood lignin of bamboo were subjected to comprehensive structural characterization using gel permeation chromatography (GPC), Fourier transform infrared (FTIR) and solution-state NMR techniques ( 1 H, 13 C, 2D-HSQC, and 31 P-NMR spectroscopies). The results indicated that the formic acid fractionation under high pressure presents a quick and efficient delignification method by enhancing the cleavage of interunitary bonds in lignin (β-O-4′, β-β and β-5′), and dissolved lignin also occurred condensation reaction. As compared to atmospheric formic acid lignin, high-pressure formic acid lignin obtained showed higher purity and yield, and had relatively higher contents of phenolic and carboxylic groups.

Thermal management is a key issue for high-power light-emitting diodes (LEDs). In this study, a novel packaging structure was proposed to reduce the die-bonding interface thermal resistance and provided a new idea for LED heat-dissipation. The LED chip was embedded into a square groove at the lead-frame substrate. The gap between the edges of the LED chip and square groove was filled with boron nitride/silicone composite. So the heat generated from the chip could be dissipated from the side surfaces to the substrate. The experimental results show that the heat-dissipation ability of LEDs has been significantly improved by the new embedding packaging structure. The die-bonding interface thermal resistance can be reduced by more than 20%. The junction temperature rise can be reduced by 14%. Due to the fully embedding of LED chip in the square groove, the light intensity distribution is slightly shrunk and the light output power is slightly reduced by about 8%.

The incentives for utilizing a versatile range of renewable feedstocks in novel ways are continuously increasing. Sulfated polysaccharides from green algae, such as ulvan, are interesting due to th ...

The traditional method to isolate cellulose nanocrystals (CNCs) is to subject cellulosic materials to strong acid hydrolysis by mineral acids, which usually causes problems such as corrosion of equipment, the need for large amounts of water, the difficulty of acid recovery, and over-degradation of cellulose. Thus, a green and sustainable approach for the preparation of CNCs was developed where mild acid hydrolysis with diluted oxalic acid was used. The reaction kinetics of different preparation parameters, such as reaction temperature, oxalic acid dose, addition of HCl, and reaction time were thoroughly investigated. A high yield of up to 85 % was achieved by mild oxalic acid hydrolysis in comparison to the yield of 35 % using the most common approach with sulfuric acid hydrolysis. The CNCs from the above approach have a high thermal stability, that is, a maximum thermal degradation temperature of 350 °C in comparison to 200 °C when sulfuric acid hydrolysis was used. Importantly, oxalic acid solutions were readily recovered, and exhibited consistently high performance in several continuous runs of reaction. The hydrolysates contained mostly monomeric sugars, which could be further utilized for chemical or biofuel production.

A water-based environmentally friendly electrically conducting ink composed of cellulose nanocrystals (CNC) and polyaniline (PANI) was prepared. PANI was synthesized by the emulsion polymerization approach using dodecylbenzenesulfonic acid (DBSA) as the dopant to induce spherical nanoparticulate formation. Glycerol was used to adjust the viscosity of the ink. The CNC–PANI ink was characterized by transmission electron microscopy, UV-visible spectroscopy and viscosity measurements. The ink was successfully printed on multilayer curtain coated paper by the flexographical printing method. The printed layers were characterized by optical and atomic force microscopy techniques and cyclic voltammetry. A stable nanoparticulate CNC–PANI ink with an electrical conductivity of the printed films between 30 and 60 S cm−1 was obtained which was more than an order of magnitude higher than for the corresponding film without CNC.

Combining chemi-mechanical pulping with autohydrolysis pretreatment is an efficient and value-added utilization approach for lignocellulosic biomass in paper industry. To further promote the utilization of autohydrolyzed biomass in chemi-mechanical pulping, the color evolution of poplar wood chips in autohydrolysis pretreatment and its chromogenic mechanism were investigated by using CIELab color system, FT-IR, NMR and GPC. The results showed that the total color difference ΔE* increased obviously, which were remarkable as the combined hydrolysis factor (CHF) increased. The lignin content led to a more significant influence on the color of poplar wood chips than the extractives. The autohydrolysis pretreatment with a higher CHF accelerated the degradation and subsequent condensation of lignin, resulting in the formation of chromophoric groups, such as Hibbert ketone, quinones and quinone methides. It is of great significance for biomass refinery and paper industry to reveal the color evolution of poplar wood chips caused by autohydrolysis pretreatment from the point of view of chemical components' structure.

Cellulose nanofibrils (CNFs) in the form of hydrogels stand out as a platform biomaterial in bioink formulation for 3D printing because of their low cytotoxicity and structural similarity to extracellular matrices. In the present study, 3D scaffolds were successfully printed with low-concentration inks formulated by 1 w/v % 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO)-oxidized CNF with less than 1 w/v % gelatin methacrylate (GelMA). Quartz crystal microbalance with dissipation monitoring (QCM-D) measurements showed strong interaction between the two biopolymers. The UV cross-linking ability of GelMA (≤1 w/v %) was enhanced in the presence of TEMPO-oxidized CNFs. Multiple factors including strong physical interaction between CNF and GelMA, in situ cross-linking of CNF by Ca2+, and UV cross-linking of GelMA enabled successful 3D printing of low-concentration inks of CNF/GelMA into scaffolds possessing good structural stability. The mechanical strength of the scaffolds was tuned in the range of 2.5 to 5 kPa. The cell culture with 3T3 fibroblasts revealed noncytotoxic and biocompatible features for the formulated inks and printed scaffolds. More importantly, the incorporated GelMA in the CNF hydrogel promoted the proliferation of fibroblasts. The developed low-concentration CNF/GelMA formulations with a facile yet effective approach to fabricate scaffolds showed great potential in 3D printing for wound healing application.

The local delivery of Cu2+ from copper-doped bioactive glass (Cu-BaG) was combined with 3D printing of polycaprolactone (PCL) scaffolds for its potent angiogenic effect in bone tissue engineering. PCL and Cu-BaG were, respectively, dissolved and dispersed in acetone to formulate a moderately homogeneous ink. The PCL/Cu-BaG scaffolds were fabricated via direct ink writing into a cold ethanol bath. The architecture of the printed scaffolds, including strut diameter, strut spacing, and porosity, were investigated and characterized. The PCL/Cu-BaG scaffolds showed a Cu-BaG content-dependent mechanical property, as the compressive Young's modulus ranged from 7 to 13 MPa at an apparent porosity of 60%. The ion dissolution behavior in simulated body fluid was evaluated, and the hydroxyapatite-like precipitation on the strut surface was confirmed. Furthermore, the cytocompatibility of the PCL/Cu-BaG scaffolds was assessed in human bone marrow stem cell (hBMSC) culture, and a dose-dependent cytotoxicity of Cu2+ was observed. Here, the PCL/BaG scaffold induced the higher expression of late osteogenic genes OSTEOCALCIN and DLX5 in comparison to the PCL scaffold. The doping of Cu2+ in BaG elicited higher expression of the early osteogenic marker gene RUNX2a but decreased the expression of late osteogenic marker genes OSTEOCALCIN and DLX5 in comparison to the PCL/BaG scaffold, demonstrating the suppressing effect of Cu2+ on osteogenic differentiation of hBMSCs. In a coculture of hBMSCs and human umbilical vein endothelial cells, both the PCL/BaG and PCL/Cu-BaG scaffolds stimulated the formation of a denser tubule network, compared to the PCL scaffold. Meanwhile, only slightly higher gene expression of vWF was observed with the PCL/Cu-BaG scaffold than with the PCL/BaG scaffold, indicating the potent angiogenic effect of the released Cu2+. publishedVersion

Willow (Salicaceae) bark contains a variety of antioxidant phytochemicals depending mainly on the hybrid. In this study, hot water extraction of willow bark was coupled with a sequential preparative scale chromatography to purify the crude extracts to a well-separated and highly concentrated phytochemical fraction. The pre-equilibrated hydrophilic weak cation exchange resins (with acrylic matrix in Na+ ions form) achieved a good separation of phytochemicals from monosaccharide fractions. Secondly, the individual phytochemical can be purified based on their size and hydrophobicity differences, using gel permeation chromatography and adsorption column chromatography. Surprisingly, the G-types of sephadex demonstrated an efficient separation of not only monosaccharides but a complete separation between (+)-catechin and triandrin. Picein and salicin can be further separated according to their hydrophobicity differences. The purified compounds can be quickly quantified using high performance liquid chromatography, gas chromatography and high-performance anion-exchange chromatography. The purified picein and triandrin were characterized by one- and two-dimensional nuclear magnetic resonance spectroscopy techniques. Additionally, the authentic compounds were applied to confirm the identification, quantification and purity. The technique described here might be a fast, economical, and highly efficient way in the large-scale isolation and purification of the phytochemical compounds from willow bark. Post-print / Final draft

Boron subphthalocyanine chloride (Cl-subPC) and its derivatives have been extensively studied due to their unique structures and attractive optical performance in organic solar cells (OSCs). However, how axial halogen substitutions of Cl-subPC influence the delicate interfacial charge transfer (CT) is still an open question. In this work, by utilizing long range corrected and constrained density functional theory with polarizable continuum model, we have modelled X-subPC/C60 (X = F, Cl, Br) bi-molecular systems and studied the effect of axial halogen substitutions on CT and charge recombination (CR) rate constants (kCTs and kCRs) with Marcus theory. Fractional transfer charges and the effects of surrounding environment are obtained with high accuracy. The results indicate that cold and hot CTs play different roles to determine exciton dissociations, and the maximum kCTs in U configurations (C60 in the concave of subPC) are much larger than those in B configurations (C60 on the convex of subPC) due to better hybridizations between local excitation and CT states. Furthermore, the order of maximum kCTs in U/B configurations is Cl > F > Br / F > Br > Cl, respectively. Finally, the calculated lifetime (2.32 ps) of excitons in Cl-subPC/C60 B configurations matches with experiment (10 ps), and the much shorter lifetime of exciton in Cl-subPC/C60 U configuration implies that this molecular arrangement may not be dominant at the interface. The theoretical study here gives a deep insight about how halogen substitutions influence the CT nature in X-subPC/C60 OSCs.

Polysaccharides are finding an increasing number of applications in medical and pharmaceutical fields thanks to their biodegradability, biocompatibility, and in some cases bioactivity. Two approaches were applied to use hemicelluloses as crosslinkers to tune the structural and mechanical properties of nanofibrillated cellulose (NFC) hydrogel scaffolds, and thus to investigate the effect of these properties on the cellular behavior during wound healing application. Different types of hemicellulose (galactoglucomannan (GGM), xyloglucan (XG), and xylan) were introduced into the NFC network via pre-sorption (Method I) and in situ adsorption (Method II) to reinforce the NFC hydrogels. The charge density of the NFC, the incorporated hemicellulose type and amount, and the swelling time of the hydrogels were found to affect the pore structure, the mechanical strength, and thus the cells’ growth on the composite hydrogel scaffolds. The XG showed the highest adsorption capacity on the NFC, the highest reinforcement effect, and facilitated/promoted cell growth. The pre-sorbed XG in the low-charged NFC network with a lower weight ratio (NFC/XG-90:10) showed the highest efficacy in supporting the growth and proliferation of fibroblast cells (NIH 3T3). These all-polysaccharide composite hydrogels may work as promising scaffolds in wound healing applications to provide supporting networks and to promote cells adhesion, growth, and proliferation.

Swollen three-dimensional nanocellulose films and their resultant aerogels were prepared as scaffolds towards tissue engineering application. The nanocellulose hydrogels with various swelling degree (up to 500 times) and the resultant aerogels with desired porosity (porosity up to 99.7% and specific surface area up to 308m(2)/g) were prepared by tuning the nanocellulose charge density, the swelling media conditions, and the material processing approach. Representative cell-based assays were applied to assess the material biocompatibility and efficacy of the human extracellular matrix (ECM)-mimicking nanocellulose scaffolds. The effects of charge density and porosity of the scaffolds on the biological tests were investigated for the first time. The results reveal that the nanocellulose scaffolds could promote the survival and proliferation of tumor cells, and enhance the transfection of exogenous DNA into the cells. These results suggest the usefulness of the nanocellulose-based matrices in supporting crucial cellular processes during cell growth and proliferation.

By aiming at tailoring the bonding strength of a thermosetting lignin-containing phenol-formaldehyde (LPF) wood adhesive, different fractions of an industrial hardwood alkaline lignin have been prepared through sequential solvent fractionation (i-PrOH, EtOH, and MeOH). Those fractions were comprehensively characterized by GPC, GC, Py/GC–MS, and NMR techniques. Lignin fractions with low molar mass and narrow dispersity, including the i-PrOH-soluble and EtOH-soluble ones, were of high purity and had more reactive sites for LPF adhesive synthesis and better accessibility due to lower degree of condensation than the high molar mass ones. Some recalcitrance of integrating high molar mass fractions covalently into the PF adhesive was observed, which was also true in the case of lignin phenolation. The tailored bonding strength of the LPF adhesive, tested by gluing wood pieces, provided strong evidence for molecular structure–performance correlation; the i-PrOH-PF had the lowest activation energy, the highest curing enthalpy, and the strongest bonding strength of 2.16 MPa. This study demonstrates a clear structure–property-application relationship of technical hardwood lignin in the LPF adhesive field, which might pave the way for a more effective bulk valorization.

Improving the heat dissipation ability for light-emitting diode (LED) filament bulb is very difficult. A tri-needle/ring ionic wind generator was developed to improve the heat dissipation condition of bulbs. The operation characteristics of the ionic wind generator, such as the electrode gap, inception voltage, and discharge current with regard to the operation voltage, were studied by experiments. The ionic wind velocity within the bulb was investigated under different electrode gaps and applied voltages. The temperature drop achieved by the ionic was were tested with the consideration of many operation parameters for analysis. The experiments showed that ionic wind can provide efficient and stable cooling effect for LED filament bulbs. The temperature drop of LED junction can reach 30 &deg, C at best. Good stability and adjustability of the ionic wind generator were demonstrated by tracing the temperature history of LED filaments in long-term tests. Finally, the light efficiency of LED filament bulbs with ionic wind cooling was studied. The experimental results showed that light efficiency was improved by 7.3% under the best cooling case. The experimental results indicate that the embedded ionic wind generator can provide an effective solution for cooling LED filament bulbs.

Chitosan has attracted much attention in drug delivery, however, carboxymethyl chitosan (CMC)-based self-aggregated nanocarriers are seldom reported. In this paper, two kinds of CMC-based pH-responsive amphiphilic chitosan derivatives, N-2-hydroxylpropyl-3-butyl ether-O-carboxymethyl chitosan (HBCC) and N-2-hydroxylpropyl-3-(2-ethylhexyl glycidyl ether)-O-carboxymethyl chitosan (H2ECC), have been synthesized by the homogeneous reaction. The molecular structures were characterized by FTIR, 1H NMR and 13C NMR. The optimum reaction condition was obtained based on the data of 1H NMR spectrum: reaction time of 4 h, reaction temperature of 80 °C and nepoxyn-NH2 of 3/1, respectively. The XRD patterns showed the crystallinity of HBCC and H2ECC decreased due to the introduction of hydrophobic segments. The thermostability of HBCC and H2ECC was improved for the formation of heat-resistant stereo-complexed structures. The intermolecular hydrophobic interaction hindered the intermolecular mobility by increasing glass transition temperature of ca. 10 °C. Both HBCC and H2ECC have very low critical aggregation concentrations (HBCC: 0.66-1.56 g/L, H2ECC: 0.57-1.07 g/L) and moderate aggregate particle size, which is advantageous for utilization as a drug carrier. The curcumin loaded HBCC and H2ECC aggregates showed nontoxicity, meanwhile, HBCC and H2ECC showed good antibacterial activity against Staphylococcus aureus and Escherichia coli. As a result of these two favorable properties, HBCC and H2ECC could be used as curcumin nanocarriers as well as antibacterial agents.

Boron subphthalocyanine chloride (subPC)/C70 organic solar cell has been studied theoretically and experimentally. However, the electron transfer and charge recombination at the interface between subPC and C70 is rarely studied. It is still an open question how molecular arrangements and orientations influence its charge transfer properties at the subPC/C70 interface. Therefore, in this work, by utilizing reliable density functional theory and time-dependent density functional theory, we have modelled six possible bi-molecular systems to simulate molecular arrangements at the interface, and calculated charge transfer and charge recombination rate constants between multiple excited states in gas phase. The results indicate that the exciton life time at the interface ranges from 70.9 fs to 7.81 ps. The outcomes also suggest the charge separation process occurs dominantly in the umbrella configurations in which C70 is in the concave of subPC, and almost is unlikely to happen in other configurations. The findings propose that it would be a promising way to improve the performance of subPC/C70 solar cell by increasing the ratio of umbrella configurations at the interface during fabricating processes.

Willow bark is a rich source of heterogeneous polyphenolic compounds and a potential feedstock for biorefinery processes aiming at chemicals and fiber production. Here, mild hot water treatment of willow hybrid Karin was studied to find a practical means of isolating its non-cell-wall components for their utilization in a willow biorefinery proposed to aid valorization of the willow biomass. A short aqueous treatment of the bark at 80 °C liberated the extract in >20% yield under unpressurized conditions. The extract was characterized using mainly gas chromatography-mass spectrometry and one- and two-dimensional NMR techniques. Authentic analytes were applied to confirm the identification and quantification of the main components that were picein, (+)-catechin, triandrin, glucose, and fructose. Fructose was converted into 5-hydroxymethylfurfural in an acidic treatment which led to its condensation with the phenolic components and formation of a recalcitrant precipitate that should be avoided. © 2018 American Chemical Society.

It is demonstrated that the molecular solubility of softwood hemicelluloses is significantly influenced by pretreatment of the fibers, extraction, and downstream processing. To quantify these effects, four hemicellulose samples were extracted from different thermomechanical pulps of Norway spruce. The molecular solubility of the samples was characterized by size and molar mass distributions, and the morphology of the molecules was studied using high resolution microscopy techniques. All extracted samples were well dispersed in aqueous media creating transparent dispersions, but dynamic light scattering measurements showed that molecular solubility can only be achieved using specific pretreatments and extractions. The procedure yields acetylated galactoglucomannan (AcGGM)-rich hemicelluloses with an average molar mass of 21-35 kDa and a diameter up to 10 nm but also shows that water is a poor solvent for this sample since an association is detected as soon as the concentration is about 20 g/L. These associated hemicellulose dispersions are still absolutely clear on visual inspection, underlining the need for careful measurement when assessing the solubility of wood hemicelluloses.

Wood-derived biopolymers have attracted great attention over the past few decades due to their abundant and versatile properties. The well-separated three main components, i.e., cellulose, hemicelluloses, and lignin, are considered significant candidates for replacing and improving on oil-based chemicals and materials. The production of nanocellulose from wood pulp opens an opportunity for novel material development and applications in nanotechnology. Currently, increased research efforts are focused on developing 3D printing techniques for wood-derived biopolymers for use in emerging application areas, including as biomaterials for various biomedical applications and as novel composite materials for electronics and energy devices. This Review highlights recent work on emerging applications of wood-derived biopolymers and their advanced composites with a specific focus on customized pharmaceutical products and advanced functional biomedical devices prepared via three-dimensional printing. Specifically, various biofabrication strategies in which woody biopolymers are used to fabricate customized drug delivery devices, cartilage implants, tissue engineering scaffolds and items for other biomedical applications are discussed.

Hemicelluloses, the second most abundant polysaccharide right after cellulose, are in practice still treated as a side-stream in biomass processing industries. In the present study, we report an approach to use a wood-derived and side-stream biopolymer, spruce wood hemicellulose (galactoglucomannan, GGM) to partially replace the synthetic PLA as feedstock material in 3D printing. A solvent blending approach was developed to ensure the even distribution of the formed binary biocomposites. The blends of hemicellulose and PLA with varied ratio up to 25% of hemicellulose were extruded into filaments by hot melt extrusion. 3D scaffold prototypes were successfully printed from the composite filaments by fused deposition modeling 3D printing. Combining with 3D printing technique, the biocompatible and biodegradable feature of spruce wood hemicellulose into the composite scaffolds would potentially boost this new composite material in various biomedical applications such as tissue engineering and drug-eluting scaffolds.

This paper presents numerical studies on thermal performance of LED filament light bulbs with different bulb sizes, phosphor diameters, and phosphor shapes. A quarter of numerical model of LED filament light bulbs was built to analyze the temperature field, velocity field and distributions for convective heat flux coefficient on the filament surface. The effects of bulb sizes, phosphor diameters and phosphor shapes on the thermal performance were investigated. The maximum temperature of a type of commercial LED filament light bulb reaches 145 °C, which can be reduced by the increasing of bulb sizes and phosphor diameters. When the phosphor diameter increases from 2 mm to 5 mm, the maximum temperature is reduced by 24 °C, which is also decreased by 10 °C with the increased bulb size of 4 mm. In addition, fin-shape filaments can effectively reduce the bulb temperature, and the maximum temperature reduction is 10 °C when the fin length reaches 0.91 mm.

Thermal dissipation for Light emitting diode (LED) filament bulb is a very important issue. The heat dissipation ability of LED filament bulb is limited by its complex structure. In this study, a novel cooling method for LED filament bulb based on ionic wind was presented. The bulb was embedded with needle to ring electrodes as ionic wind generator. Once there was ionic wind produced in the bulb, the heat convection between the LED filaments and the air is enhanced. The flow status of ionic wind in the bulb was analyzed by Computational Fluid Dynamics (CFD) method. The LED junction temperature of the filaments was obtained by forward voltage method. The experimental results showed that the LED junction temperature was dramatically reduced. The LED junction temperature can be reduced by more than 30 V. The cooling solution proposed in this study can help to improve the product quality and broaden the application future of LED filament bulb.

The effects of N-(2-hydroxyl)-propyl-3-trimethylammonium chitosan chloride (HTCC) on the physicochemical properties of sodium carboxymethyl cellulose (CMC)-based films were investigated. The prepared HTCC/CMC film-forming solutions (FFSs) with varying mass ratios exhibited shear-thinning behavior and typical pseudo-plasticity. The highest apparent viscosity and lowest crossover frequency was obtained for the HTCC/CMC FFS with a mass ratio of 10%, due to the formation of the strongest intermolecular interactions, which also led to the best mechanical properties. Furthermore, the effects of temperature and degree of substitution of HTCC on the composite film properties were also investigated. Structural property assessment by FTIR, SEM, and DSC showed a clear interaction between HTCC and CMC, leading to the formation of a new composite material with enhanced physicochemical properties. The data demonstrate the importance of HTCC in CMC-based films for food and drug packaging.

Quantum dots (QDs) have been developed as a promising light-converting material for light-emitting diodes (LEDs). However, QDs-polymer film always shows bad thermal performance. In this paper, a new designed structure of QDs-polymer film via electrospinning was proposed to enhance the thermal conductivity of the QDs-polymer film. After the measurement of density, specific heat and thermal diffusivity, the thermal conductivities of the proposed and traditional QDs-polymer films were calculated and compared. Finite-element simulation was conducted to assess the working temperature when both kinds of QDs-polymer films were packaged in the remote QD-LEDs. Results show that the thermal conductivities in thickness direction and in plane have been enhanced by 64.6% and 423.1% at 25 °C. The highest temperature in QDs-polymer film is decreased from 92.9 °C to 88.0 °C at the driving current of 300 mA.

Light-emitting diode (LED) lamps, regarded as ‘green lighting’ fourth-generation light sources, are applied widely to many applications around us. Meanwhile, the chip-on Board (COB) packaging is a fatal important kind of packaging method for LED, with many advantages, such as bigger optical power, more compact size, loss manufacturing cost, and good reliability. However, low light extraction efficiency (LEE) is one of the most challenging points for the COB packaging. In this paper, a method of fabricating micro-lens array was proposed based on the ion wind generation. Using this method, fabricating of micro-lens array, the structure of the micro-lens array can be controlled through the process of adjusting the parameters of the ion wind generation, such as changing the voltage or the distance between the electrodes. As a result, the experimental results show that the light extraction efficiency of COB improved obviously, increasing the light extraction efficiency to 8.24%, 6.36%, 8.59%, 5.94%. This method of fabricating micro-lens arrays would be a potential way in improving the LEE of COB with high luminous efficiency.

The aim of this paper is to study the heat dissipation enhancement effect of LED filament bulb by using ionic wind. A LED filament bulb with 6 filaments is used for studying. There are two holes drilled at the end of the bulb and the ionic wind blows into the inner space of the bulb through the holes that will strengthen the heat convection of the filaments. The ionic wind generator includes the needle-net electrode, the flow channel and a high voltage DC power supply. The temperature of the filament is measured by an infrared thermal image instrument. According to the experiment results, the drop of filament surface temperature can reach to about 15°C with the corona discharge volatage higher than 9kV.

© 2016 Elsevier LtdHydrogels with tunable mechanical properties based on O-acetyl-galactoglucomannans (GGMs) from spruce functionalized with tyramine, a molecule containing crosslinkable phenolic groups, were prepared. Gel formation was induced by enzymatic crosslinking at the addition of horse radish peroxidase and hydrogen peroxide to the modified GGMs. The degree of substitution determined the hydrogels final properties, and was varied by TEMPO oxidation of GGM to a degree of oxidation from 10 to 60%. GGM and its derivatives were characterized by gas chromatography and high pressure size exclusion chromatography to analyze sugar composition and molar mass, respectively. Tyramine-conjugated GGM was evaluated by nuclear magnetic resonance, fourier transform infrared spectroscopy and elemental analysis. Measurements of moduli over time showed crosslinking within 20 s and maximum stress of the prepared gels were compared by compression testing. Overall this system presents a cell friendly hydrogel from a renewable, low cost resource which could be applied in cell delivery, wound dressings, and biofabrication.

New types of hydrogels derived from O-acetyl galactoglucomannan (AcGGM) hemicellulose have been synthesized and characterized. The objective of this work was to analyze the sorption capacity (S) of three types of hydrogels containing AcGGM derivatives incorporated into the carboxylic groups of the polymer chain in the AA hydrogel, sulfonic groups in the APA hydrogel, and amide groups in the acrylamide (Aam) hydrogel. These hydrogels are capable of interacting and removing ions such as cadmium [Cd(II)], copper [Cu(II)], lead [Pb(II)], nickel [Ni(II)], and zinc [Zn(II)]. The results show that AA and Aam hydrogels had a lower sorption capacity of ions compared to the APA hydrogel, which had a high sorption capacity. The maximal sorption capacity was determined by the successive enrichment method, obtaining Pb(II) amount of 48.3 mg/g of AA hydrogel, 65.8 mg/g of APA hydrogel, and 40.8 mg/g of Aam hydrogel. Hence, Pb(II) ions are greatly retained by the three hydrogels. These results are promising for the development of new materials with potential applications in metal ion removal. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44093.