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In recent years, shape memory polyurethanes have gained substantial attention and are targeted for a range of smart and functional materials. In this work, the development of nanocrystalline celluloses (CNCs) enabled polycaprolactone-based shape memory polyurethane biocomposite using an in situ one-pot reactions is reported. The incorporation of up to 10 wt. % CNCs resulted in a remarkable enhancement in the tensile strength at yield (from 0.2 MPa to 7.2 MPa), tensile strength at break (167% improvement), and modulus of elasticity (from 3.5 to 139.3 MPa) while maintaining the elongation at break. This was attributed to the simultaneous action of CNCs as a nucleating agent for crystallization and highly compatibilized reinforcing agent of the network. Moreover, the in situ incorporation of CNCs enhanced the shape memory capability of polyurethanes, which enables its employment in functional material applications, such as the biomedical sector. The intimate interfacial adhesion between the CNCs and the polymer matrix, which promoted shape fixating and recovery, was confirmed by fractured surface morphology studies. Rheology characterizations provided strong evidence that the addition of CNCs increased the shape fixity attributed to the stiffness of CNCs below the glass transition temperature (Tg) compared to the neat PU in conjuncture with the higher Tg of CNCs. Overall, the developed polymer nanocomposites are appealing materials for biomedical applications.

A well adherent thin films of Aluminum doped zinc sulphide (Al:ZnS) has been deposited on silica glass substrates using acidic chemical bath deposition (CBD) containing zinc acetate, Aluminum Chloride, and thioacetamide. EDTA was used as complexing agent to control the free ion concentration of the thin films. Aluminum concentrations were doped by 2%, 4%, and 6% while keeping other deposition parameters constant as deposited Al:ZnS thin films. The samples were characterized by BrukerD8 diffractometer with cuKα (λ=1.5406A˚) radiation working at 40 mA and 40 kV, JOEL-2300 Analysis Station Scanning electron microscope (SEM), and Perkin Elmer Lambda 950 UV-vis/NIR spectrophotometer. The structural characterization of the samples show that no intense peaks were observed indicating the amorphous nature of the films. The surface morphology studies of as deposited Al:ZnS thin films shown the films were uniform, dense, and composed of spherical shaped grains. EDAX shows the elemental composition of Zn, S, and Al. The ratios of Zn/S in Stoichiometric even though the concentration of Aluminum is increased. Optical absorbance of the films decreased with increase Aluminum concentration. The large band gap makes them good materials for application as a window layer for solar cells.

Research on the use of bio-based material rather than fossil fuel-based synthetic polymers is of considerable value due to the increasing interest in biodegradable and ecofriendly products. This paper describes an in-depth analysis of the effect of cellulose nanocrystals (CNC), a promising nanomaterial filler derived from cellulosic biomass, on the mechanical properties of rubber latex thin sheets. Sheets of styrene butadiene rubber (SBR) and its bio-based alternative, natural rubber (NR) were tested and compared. Percolation of CNC was studied within the rubber matrices, where the tear strength, water permeability, and water absorption increased due to the formation of a continuous network of CNC within the polymer thin sheets. The rubber nanocomposites were resistant to tear propagation, caused by increased tortuosity along the tear path brought about by CNC dispersion and filler network formation. The CNC reinforcement yielded thin sheets that were much stronger and more durable than their non-reinforced counterparts. Additionally, the increased water uptake of the sheets could aid in the biodegradation of the polymer. Thus, CNC is found to be an excellent functional filler in rubber sheets, where its formation of a percolating network significantly improved their properties.

Cellulose nanocrystals (CNCs) have been modified through surface graft polymerization of (l)-lactide for the purpose of improving dispersion and reducing aggregation of CNCs into chloroprene rubber (CR). Statistically designed experiments have been carried out to study the effects of polymerization conditions (temperature, and catalyst and monomer concentrations) on water contact angle, solvent dispersibility, and particle size distribution of the produced mCNCs. The effects of catalyst concentration and interaction of monomer-catalyst concentrations were found to be significant. Dry films produced from mCNCs exhibited surface hydrophobicity as evidenced by very high water contact angles (> 90°). In addition, mCNCs in powder form exhibited very good water/latex dispersibility. Blending of mCNCs with CR latex resulted in well-dispersed modified CNC/CR composites based on microscopy observations. The tensile properties of cast films produced from CNC/CR and mCNC/CR composites have been evaluated and it has been found that increasing the CNC and mCNC content increases tensile strength and modulus while maintaining elongation at break close to that of the unfilled CR. Composites containing 3 wt% of mCNCs exhibited the best properties with tensile strength and modulus improving by about 200% and 450%, respectively. These results are very promising and suggest that these mCNC/CR composites could find applications in the manufacturing of cut/fat resistant medical gloves, balloons, catheters, and other biomedical devices.

Cellulose nanocrystals (CNCs), a robust renewable and green nanomaterial, has potential as an excellent reinforcing and multifunctional filler for polymers used in coating and other applications. However, the high polarity of CNCs limits its interfacial interaction and dispersibility with several non-polar polymers. These limitations severely constrain it from transferring its functional attributes to polymeric materials. In this paper, three differentiated cationic surfactants: cetyltetramethylammoniumbromide (CTAB, C16 single chain), dimethyldidodecylammonium bromide (DDAB, C12 double chains) and dimethyldihexadecylammonium (DHAB, C16 double chains) were used to modify the surface of CNCs. The modifications were confirmed using Fourier-Transform Infrared Spectroscopy (FTIR) and elemental analysis. X-ray diffraction (XRD) and thermogravimetric analysis (TGA) of the samples revealed that the crystallinities and the thermal stabilities of the modified CNCs were preserved. Corrosion protection studies of epoxy nanocomposites containing the native and surfactant modified CNCs were conducted using model steel specimens via salt spray and electrochemical test methods. The results reported herein indicated that the use of surfactant modified CNCs resulted in an enhanced dispersibility in the epoxy matrices as compared to native CNCs. The improved dispersion assisted in retardation of the penetration of electrolyte that caused a remarkable improvement in the metal corrosion protection performance, as compared to unfilled or native CNC filled epoxy coatings.

Doping of non-linear optical materials by different elements and compounds is the common method to tune the various properties of these materials. In this work we report single crystals of undoped and lanthanum chloride (LaCl3) doped L-Alanine Maleate (LAM) grown by slow evaporation solution growth method at room temperature. From the single crystal X-ray diffraction analysis it was observed that both undoped, 1 and 2 mol% LaCl3-doped LAM samples were crystallized in the orthorhombic crystal system with P212121 space group. The optical properties of the LAM single crystals investigated by UV–VIS/NIR spectrometer revealed that the crystals were transparent in the wavelength range of 300–1100 nm. The band gap of the undoped and LaCl3 doped LAM single crystals were found to be 4.13 eV. Energy dispersive X-ray analysis confirmed the incorporation of LaCl3 in LAM single crystals. Simultaneous TG/DT analysis revealed the thermal stability of the samples below 145 °C. The second harmonic generation efficiency of the samples was analyzed by Kurtz-Perry powder technique and compared with the standard KDP crystal.

Injectable thermo-responsive hydrogels have been studied for various biomedical applications including; drug delivery, cell encapsulation, and tissue repairing. There are various natural and synthetic polymers which exhibit homogenous injectable solution at ambient temperature and form a gel in human body temperature. Polysaccharide, polypeptide and other biological macromolecule based hydrogels have been getting immense attention in biomedical application due to their low immunogenicity, abundance in nature, high biocompatibility and biodegradability. This manuscript focuses on polysaccharide and polypeptide based thermo-sensitive hydrogels, and some synthetic polymers which forms in situ gel in response to temperature change from ambient to body temperature. The value of numerous reactive functional groups of biological macromolecular polymers has been discussed for effortless modification and design of bio-macromolecule based thermo-sensitive hydrogels. In addition, we emphasized on the basic mechanisms of the thermo-response processes, the strategies to optimize the desired properties and their applications in local delivery approach.

Developing renewable resource-based plastics with complete biodegradability and a minimal carbon footprint can open new opportunities to effectively manage the end-of-life plastics waste and achieve a low carbon society. Polyhydroxyalkanoates (PHAs) are biobased and biodegradable thermoplastic polyesters that accumulate in microorganisms (e.g., bacterial, microalgal, and fungal species) as insoluble and inert intracellular inclusion. The PHAs recovery from microorganisms, which typically involves cell lysis, extraction, and purification, provides high molecular weight and purified polyesters that can be compounded and processed using conventional plastics converting equipment. The physio-chemical, thermal, and mechanical properties of the PHAs are comparable to traditional synthetic polymers such as polypropylene and polyethylene. As a result, it has attracted substantial applications interest in packaging, personal care, coatings, agricultural and biomedical uses. However, PHAs have certain performance limitations (e.g. slow crystallization), and substantially more expensive than many other polymers. As such, more research and development is required to enable them for extensive use. This review provides a critical review of the recent progress achieved in PHAs production using different microorganisms, downstream processing, material properties, processing avenues, recycling, aerobic and anaerobic biodegradation, and applications.

Historically, lignin has been produced as a waste by-product in industrial processes. In this study, lignosulfonate nanoparticles were fabricated and freeze-dried for use as a precursor material for carbonization. The use of the carbonized lignins for the adsorption of textile effluent as a value-added application is demonstrated. Characterization of the as received lignin (LN) and the developed nano-based freeze-dried lignin (NFLN) were performed prior to and after carbonization at 600, 750, 900 and 1050 °C. Using probe sonication, lignosulfonates were broken down into nanoparticles with lower weight-average molecular weight as verified by dynamic and static light scattering techniques. The difference between the LN and the NFLN was determined to be primarily morphological as the sonication and freeze-drying process imparted a platelet-like shape to the NFLN biocarbons and an increased surface area, while the remaining functionality was similar. The adsorption behaviour of methylene blue (MB), a synthetic cationic dye, was investigated using adsorption isotherm and kinetic models, with the NFLN exhibiting a maximum adsorption capacity of 109.77 mg/g. Overall, electrostatic attraction and hydrogen bonding contribute significantly to the MB adsorption. Further preliminary work was also performed demonstrating the coating of polyurethane foam for the adsorption of MB. These renewable biocarbons show promising properties for use as additive in adsorbent, coating, pigment or as a filler in polymer composite applications.

Integrating anticancer drugs and diagnostic agents in a polymer nanosystem is an emerging and promising strategy for improving cancer treatment. However, the development of multifunctional nanoparticles (NPs) for an "all-in-one" platform characterized by specific targeting, therapeutic efficiency, and imaging feedback remains an unmet clinical need. In this study, pH-responsive mixed-lanthanide-based multifunctional NPs were fabricated based on simple metal-ligand interactions for simultaneous cancer cell imaging and drug delivery. We investigated two new systems of alginate-polydopamine complexed with either terbium/europium or dysprosium/erbium oxide NPs (Tb/Eu@AlgPDA or Dy/Er@AlgPDA NPs). Tb/Eu@AlgPDA NPs were then functionalized with the tumor-targeting ligand folic acid (FA) and loaded with the anticancer drug doxorubicin (DOX) to form FA-Tb/Eu@AlgPDA-DOX NPs. Using such systems, the mussel-inspired property of PDA was introduced to improve tumor targetability and penetration, in addition to active targeting (via FA-folate receptor interactions). Determining the photoluminescence efficiency showed that the Tb/Eu@AlgPDA system was superior to the Dy/Er@AlgPDA system, presenting intense and sharp emission peaks on the fluorescence spectra. In addition, compared to Dy/Er@AlgPDA NPs (82.4%), Tb/Eu@AlgPDA NPs exhibited negligible cytotoxicity with93.3% HeLa cell viability found in MTT assays at NP concentrations of up to 0.50 mg/mL and high biocompatibility when incubated with zebrafish (

The present study evaluated first the characterization of Teff straw and then Box–Behnken design (BBD), and response surface methodology was adopted to optimize the parameters (hydrolysis temperature, dilute sulfuric acid concentration, solid to liquid ratio, and hydrolysis time) of dilute sulfuric acid hydrolysis of Teff straw in order to get a maximum yield of total reducing sugar (TRS). The chemical analysis of Teff straw revealed high amounts of cellulose (41.8 wt%), hemicellulose (38 wt%), and lignin (17 wt%). The morphological analysis using SEM showed that hydrolyzed Teff straw with dilute sulfuric acid has more pores and distorted bundles than those of raw Teff straw. XRD analysis also indicated that hydrolyzed Teff straw has higher crystallinity index and smaller crystallite size than raw Teff straw, which might be due to removal of hemicellulose, amorphous cellulose, and lignin components. Under the optimized conditions for dilute sulfuric acid hydrolysis of Teff straw (120°C, 4% v/v H2SO4 concentration, 1 : 20 solid to liquid ratio, and 55 min hydrolysis time), we have found a total reducing sugar yield of 26.65 mg/g. The results of validation experiment under the optimum conditions agreed well with model predictions.

Poly(vinyl alcohol) (PVA) is a water-soluble polymer and forms a hydrogel that has been studied as a potential small-diameter (

Background. As the dietary iodine content depends on the iodine contents of the soil where the crop is harvested, in highland areas where the iodine content of topsoil was washed away due to erosion, iodized salt is the main source of iodine. This study assessed the magnitude of iodine deficiency disorder and knowledge about the benefit and food sources of iodine among adolescent girls in the highland areas of the North Shewa Zone, Amhara Region, central Ethiopia. Methods. An institutional cross-sectional study was conducted from October 5, 2018, to December 30, 2019. Through a multistage sampling technique, 625 adolescent school girls were selected from 9 schools. A pretested semistructured self-administered questionnaire was used for data collection. Anthropometric measures and thyroid gland physical examinations were performed by trained nurses. The collected data were entered into the computer through Epi Data 3.1 software, and analysis was performed using Anthro plus and SPSS software. Results. The total goiter rate was 317 (50.7%) with 95%CI of 46.9% to 54.6%. Grade-one and grade-two goiter accounts 226 (36.2%) and 91 (14.6%), respectively. About one-third, 428 (68.5%), had knowledge about locally available iodine source foods and 309 (72.2%) of them mentioned salt as a source of iodine. Over half, 216 (55.1%), of 392 (62.7%) participants who had knowledge about the benefit of iodine knew it prevents goiter. Diet diversity score of

This study is aimed at utilizing brewery’s spent grain (BSG) byproduct for the synthesis of cellulose nanocrystals (CNCs) using acid hydrolysis and optimizing the hydrolysis parameters (hydrolysis time, temperature, liquid-solid ratio, and acid concentration). Alkali and bleaching treatment were done to remove hemicellulose and lignin from BSG. Optimization process was performed using central composite design (CCD) to obtain optimum value of cellulose nanocrystal (CNC) yield. The maximum cellulose nanocrystal (CNC) yield of 43.24% was obtained at optimum hydrolysis conditions of 50°C, 51 wt% acid concentration, 41 min, and liquid-solid ratio of 19 ml/g. The raw brewery spent grain; alkali-treated fiber, bleached fiber, and obtained CNC were characterized using scanning electron microscopy (SEM), XRD, particle analyzer, FTIR, and differential scanning calorimeter (DSC). The characterization results indicated that the obtained cellulose nanocrystal (CNC) has rod-like whisker shape with crystallinity of 76.3% and an average particle size of 309.4 nm.

Starch-based edible films are gaining huge interest in food packaging industries. In the present work, avocado seed starch (ASS) was extracted and used to develop an edible film. The influence of four important process factors, starch, agar, sorbitol, and Tween-20, was studied on one of the important barrier properties, water-vapor permeability (WP), of developed edible film. The three-level RSM design with Box–Behnken approach was carried out to investigate the film property, WP. ASS-based edible films were prepared by the casting method. The results revealed that the increment in the contents of Tween-20 and sorbitol reduces the WP of the film. Using the response surface analysis, the effect of the aforementioned factors was analyzed; they showed significant impact on WP. To predict the influence of the selected process parameters, a second-order polynomial equation was constructed. Additionally, Pareto analysis of variance was employed over the obtained results to investigate the significance of the developed process model.

Non-isothermal thermogravimetric analysis (TGA) was employed to investigate the degradation of polypropylene (PP) during simulated product manufacturing in a secondary process and wood&ndash, plastic composites. Multiple batch mixing cycles were carried out to mimic the actual recycling. Kissinger&ndash, Akahira&ndash, Sunose (KAS), Ozawa&ndash, Flynn&ndash, Wall (OFW), Friedman, Kissinger and Augis models were employed to calculate the apparent activation energy (Ea). Experimental investigation using TGA indicated that the thermograms of PP recyclates shifted to lower temperatures, revealing the presence of an accelerated degradation process induced by the formation of radicals during chain scission. Reprocessing for five cycles led to roughly a 35% reduction in ultimate mixing torque, and a more than 400% increase in the melt flow rate of PP. Ea increased with the extent of degradation (&alpha, ), and the dependency intensified with the reprocessing cycles. In biocomposites, despite the detectable degradation steps of wood and PP in thermal degradation, a partial coincidence of degradation was observed under air. Deconvolution was employed to separate the overlapped cellulose and PP peaks. Under nitrogen, OFW estimations for the deconvoluted PP exposed an upward shift of Ea at the whole range of &alpha, due to the high thermal absorbance of the wood chars. Under air, the Ea of deconvoluted PP showed an irregular rise in the initial steps, which could be related to the high volume of evolved volatiles from the wood reducing the oxygen diffusion.

Biotin receptors are overexpressed by various types of solid cancer cells and play a significant role in tumor metabolism, growth, and metastasis. Thus, targeting the biotin receptors on tumor cells may enhance the efficiency and reduce the side-effects of chemotherapy. The aim of this study was to develop a biotin-coupled poly(amido)amine (PAMAM) (PG4.5) dendrimer nanoparticle to enhance the tumor-specific delivery and intracellular uptake of anticancer drugs via receptor-mediated endocytosis. We modified PG4.5 with diethylenetriamine (DETA) followed by biotin via an amide bond and characterized the resulting PG4.5-DETA-biotin nanoparticles by 1H NMR, FTIR, and Raman spectroscopy. Loading and releasing of gemcitabine (GEM) from PG4.5-DETA-biotin were evaluated by UV&ndash, Visible spectrophotometry. Cell viability and cellular uptake were examined by MTT assay and flow cytometry to assess the biocompatibility, cellular internalization efficiency and antiproliferative activity of PG4.5-DETA-biotin/GEM. Gemcitabine-loaded PG4.5-DETA-biotin nanoparticles were spherical with a particle size of 81.6 &plusmn, 6.08 nm and zeta potential of 0.47 &plusmn, 1.25 mV. Maximum drug-loading content and encapsulation efficiency were 10.84 &plusmn, 0.16% and 47.01 &plusmn, 0.71%, respectively. Nearly 60.54 &plusmn, 1.99% and 73.96 &plusmn, 1.14% of gemcitabine was released from PG4.5-DETA-biotin/GEM nanoparticles after 48 h at the acidic pH values of 6.5 and 5, respectively. Flow cytometry and fluorescence microscopy of cellular uptake results revealed PG4.5-DETA-biotin/GEM nanoparticles selectively targeted cancer cells in vitro. Cytotoxicity assays demonstrated gemcitabine-loaded PG4.5-DETA-biotin significantly reduced cell viability and induced apoptosis in HeLa cells. Thus, biotin-coupled PG4.5-DETA nanocarrier could provide an effective, targeted drug delivery system and selectively convey gemcitabine into tumor cells.

Graphical abstract, Highlights • C. citrates essential oil contains about 71.297 % citral. • 10 % ointment formulation of C. citratus oils did not cause skin irritation. • Oral LD50 of C. citratus essential oil was greater than 2000 mg/kg. • C. citratus essential oil didn’t produce any toxicity sign. • No histopathological changes were detected in the organs tested., Cymbopogon citratus has been used by the local people in Ankober district, northern Ethiopia, as traditional medicine to treat various ailments. Its essential oil has been shown to have antibacterial, antifungal, antiprotozoal, anti-carcinogenic, anti-inflammatory and antioxidant activities amongst others. This study was conducted to determine skin irritation, acute and subacute toxicity of C. citratus essential oil in mice and rabbits. The essential oil was analyzed using GC–MS. The essential oil at dose of 2000 mg/kg body weight was administered to mice for 21 consecutive days. The mice mortality, behavioral change, injury and other signs of illness were recorded once daily. Biochemical parameters were evaluated. Liver and kidney were taken after sacrifice for gross findings and histological analyses. 10 % ointment formulation of C. citratus oils was applied on the rabbit skin to determine skin irritation effects. The result revealed, the presence of citral (71.297%), myrcene (19.034%), 4, 5-epoxycarene (2.780%), linalool (1.713%), ((S)-cis-verbenol (1.110 %), linalool (1.713 %), ((S)-cis-verbenol (1.110 %) and undecan-2-one (1.001 %) in the C. citratus essential oil. There was no significant difference (p > 0.05) in the body weights, gross abnormalities of the organs and biochemical parameters compared to the control. No histopathological changes were detected in the organs tested. 10 % ointment formulation of C. citratus oils did not cause skin irritation. Analysis of results leads to the conclusion that Ethiopian C. citratus essential oil may be considered as relatively safe and non-toxic.

Epoxy is an extensively used polymer in several applications such as coatings, adhesives, structural composites etc. However, it is a poor ultraviolet (UV) absorber and suffers from UV-degradation, which usually leads to discoloration and loss of structural integrity. In this study, cellulose nanocrystals (CNCs) conjugated with a UV absorbing molecule were investigated as a functional nanomaterial to enhance the UV absorption of epoxy polymers. The grafting of a UV absorbing molecule, para-aminobenzoic acid (PABA), on the surface of CNCs was confirmed using FTIR, proton NMR, and via elemental analysis. The modified CNCs were then incorporated into an epoxy polymer and their efficacy in mitigating the photo-degradation of epoxy was evaluated. For this, a neat epoxy control, native CNCs and modified CNC based nanocomposite specimens were subjected to controlled UV irradiation and the resulting structure–property changes were assessed. Results of UV absorption and discoloration showed that the neat epoxy was impacted the most as a result of the UV irradiation. While the incorporation of native CNCs displayed some UV absorption and reduction in the UV mediated discoloration of the epoxy polymer, the most pronounced effect was obtained in PABA decorated CNC based epoxy nanocomposites. The use of such tailored CNCs has great potential to mitigate UV induced degradation of a range of polymers that are used especially in outdoor applications where direct exposure to UV is significant.

Ternary cadmium zinc sulfide (Cd1−xZnxS) thin films were deposited by chemical bath deposition method for the entire range of 0 ≤ x ≤ 1 from acidic chemical bath using tartaric acid and hydrazine as a complexing agents. The X-ray diffraction (XRD) studies revealed that the deposited thin films had hexagonal crystal structure in the range of 0 ≤ x ≤ 0.6 and pure cubic phase at x = 1, whereas, the thin films deposited in the range of 0.72 ≤ x ≤ 0.9 had a mixed cubic and hexagonal structures. Furthermore, the XRD results showed that the crystalline size and lattice constants were decreased linearly with the gradual incorporations of zinc ion in the Cd1−xZnxS thin films. The optical spectroscopy investigation established that the band gap of the deposited ternary thin films found in the range of 3.84 eV to 3.94 eV. The scanning electron microscope studies illustrated that the surface morphologies of the prepared thin films were formed from spherical grains. The presence of cadmium, sulfur and Zinc elements in the synthesized thin films were confirmed by the energy dispersive x-ray analyses. The unusual large band gap obtained for pure cadmium sulfide and ternary Cd1−xZnxS thin films deposited under the present deposition condition together with the preferred orientation along the (002) plane make these thin films useful as a buffer layer in thin film solar cells.

This study has investigated ultrasound-assisted xylitol production through fermentation of dilute acid (pentose-rich) hydrolysate of sugarcane bagasse using free cells of Candida tropicalis. Sonication of fermentation mixture at optimum conditions was carried out in ultrasound bath (37 kHz and 10% duty cycle). Time profiles of substrate and product in control (mechanical shaking) and test (mechanical shaking + sonication) fermentations were fitted to kinetic model using Genetic Algorithm (GA) optimization. Max. xylitol yield of 0.56 g/g and 0.61 g/g of xylose was achieved in control and test fermentations, respectively. The biomass yield also increased marginally (∼17%) with sonication. However, kinetics of fermentation increased drastically (2.5×) with sonication with 2× rise in xylose uptake and utilization by the cells. With comparative analysis of kinetic parameters in control and test experiments, this result was attributed to enhanced permeability of cell membrane that allowed faster diffusion of nutrients, substrates and products across cell membrane, higher enzyme-substrate affinity, dilution of toxic components and reduced inhibition of intracellular enzymes by substrate.

Starch as a natural polymer has attracted significant interest and is currently used in numerous industrial applications. This is because of its renewability, biodegradability, abundance, and cohesive film-forming properties. Moreover, the hydroxyl ( OH) groups associated with the anhydroglucose units provide it with several modification possibilities. These features have resulted in substantial interests for its use in several advanced functional material applications in addition to the typical consumer plastic applications. The goal of this review is to shed light on the recent advances achieved in the utilization of starch for advanced functional material applications and its derivatives. The review specifically focuses on applications ranging from electronics, drug delivery, pharmaceuticals, antimicrobial materials to structural materials.

Manganese-based nanomaterials are an emerging new class of magnetic resonance imaging (MRI) contrast agents (CAs) that provide impressive contrast abilities. MRI CAs that can respond to pathophysiological parameters such as pH or redox potential are also highly in demand for MRI-guided tumor diagnosis. Until now, synthesizing nanomaterials with good biocompatibility, physiochemical stability, and good contrast effects remains a challenge. This study investigated two new systems of calcium/manganese cations complexed with either alginate–polydopamine or alginate–dopamine nanogels [AlgPDA(Ca/Mn) NG or AlgDA(Ca/Mn) NG]. Under such systems, Ca cations form ionic interactions via carboxylic acids of the Alg backbone to enhance the stability of the synthetic nanogels (NGs). Likewise, complexation of Mn cations also increased the colloidal stability of the synthetic NGs. The magnetic property of the prepared CAs was confirmed with superconducting quantum interference device measurements, proving the potential pa...

Lignin being the second most abundant natural biopolymer after cellulose constitutes between 18 wt% and 35 wt% of wood. Due to its abundance, sustainability, renewability, and the ability to undergo numerous modifications through chemical reactions, there is a significant interest in lignin valorization for material applications. However, its hydrophilicity, lack of melt processability, and poor dispersibility have hindered its wide scale application. Structural modifications have been reported to counter its detrimental properties effectively. Thus, in the present work, a novel silylation reaction was employed to successfully modify kraft lignin and enhance its hydrophobicity. The modification was verified by using nuclear magnetic resonance and infrared spectroscopies. The change in the wettability and dispersibility in various solvent systems indicated the increase in hydrophobicity due to the modifications. This enabled it to better disperse in natural rubber composites. Lignin being the hard moiety imparted mechanical strength, while, NR being the soft moiety, provided it with elastomeric characteristics in the composites. The incorporation of 5 wt% modified lignin in the hydrophobic NR matrix led to a 44.4% increase in the tensile strength. With higher loadings of filler in composites, an increase in elastic moduli and intensity of Payne effect were recorded. The hypothesized dispersibility improvement of the modified lignin in NR compared to its unmodified counterparts was also evident from the morphological analysis.

Carbon nanoparticles (CNP) were synthesized through flame deposition method from a sustainable corn oil precursor. The morphology, particle size, surface chemistry, thermal stability, and zeta potential of the CNP were characterized. The batch adsorption of a cationic dye, methylene blue (MB), by the CNP at various concentrations, pH, and temperatures was evaluated to investigate the CNP's efficacy in industrial wastewater treatment applications. Results revealed the excellent adsorption of MB onto the CNP. The experimental data were then fitted into isotherm models, kinetic models, and thermodynamic models, and the model parameters, constants, Gibb free energy, enthalpy, and entropy were calculated and discussed. Hydrogen bonding and strong electrostatic interaction were the main adsorption mechanism for MB adsorption by the CNP. The CNP exhibited a maximum adsorption capacity of 138.89 mg/g, indicating superior adsorption of MB dye without the need for any further purification and activation steps. The adsorption efficiency did not compromise as the solution temperature increased up to 60 °C, and it can further be enhanced under alkaline conditions. To simulate the practical and industrial use of the developed CNP in textile effluent treatment, successful experiments were conducted in continuous flow adsorption by allowing concentrated MB solution to flow through a designed fixed bed purification system with a CNP filter bed.

Growth promoting hormones like auxins are now a day commercially used for rooting of many ornamental plants including roses in propagation industries of many countries. Their effects are however influenced by environmental conditions, types of plants, the rooting media and the concentrations used. This research was therefore mainly conducted to evaluate the effects of different IBA concentrations on growth and development of stenting-propagated roses. The experiment was laid down in completely randomized design with four replications in the propagation house of Tana Flora PLC. The performance of rose cuttings treated with 1500 ppm of IBA was the best in all growth parameters including shoot length, Root length, toot number etc. which can be recommended to propagate roses by stenting method in the study area.

In this study, polypropylene (PP) was reprocessed at various cycles to simulate recycling to be used as a matrix for highly loaded wood plastic composites (WPC). The neat and composite samples were produced using a batch mixer and injection molder. The extent of PP recycling was analyzed using chromatography, rheology, microscopy, and other physical/mechanical properties. While successive thermo-mechanical processing caused considerable chain scission of the PP, shown by the reduction in melt viscosity and the average molecular weight. While, other properties like tensile strength and modulus did not change significantly. The repeated reprocessing allowed for the incorporate of high 70 wt% wood flour (WF) to produce highly filled WPC. Overall, the WPCs displayed appealing physical properties through the increase in hardness and stiff characteristics while reducing the composites elongation by ~17%. This indicates that the recycling of PP could be of great importance to reduce waste accumulation by producing WPCs for construction and other applications.

Graphical abstract, Highlights • Bacillus sp. strain CH12 is a potential candidate for dye removal. • Strain CH12 needs alkaline pH (9–10) to bring complete dye removal efficiency. • Organic carbon and nitrogen supplements enhance dye decolorization efficiency. • Sodium nitrite and sodium nitrate lead to lower decolorization efficiency. • Under oxygen tension conditions, dye can be used as a final electron accepter., Textile azo dye decolorizing bacteria were isolated from alkaline Lakes Abaya and Chamo using Reactive Red 239 (RR239) dye. Through subsequent screening process, strain CH12 was selected to investigate the effects of nutrient supplement, DO, pH, temperature, dye concentration and types on decolorization. Based on 16S rRNA gene sequence analysis, strain CH12 was identified as Bacillus sp. Decolorization efficiencies were significantly enhanced with carbon (≥98%) and organic nitrogen (∼100%) supplements. Complete decolorization was also observed under anoxic and anaerobic conditions, and at the temperature of 30 °C and the pH of 10. However, the azo dye decolorization efficiency of strain CH12 was significantly reduced when NaNO3 (1–8%) was supplemented or under aerobic culturing condition (≤6%), indicating that RR239 was less preferred electron acceptor. Overall, strain CH12 can be a promising candidate for decolorization applications due to its potential to effectively decolorize higher RR239 concentrations (50−250 mg/L) and six additional dyes.

Cobalt sulfide thin films were synthesized from acidic chemical baths by varying the deposition time. The powder X-ray diffraction studies indicated that there are hexagonal CoS, face-centered cubic Co3S4, and cubic Co9S8 phases of cobalt sulfide. The crystallite size of the hexagonal CoS phase decreased from 52.8 nm to 22.5 nm and that of the cubic Co9S8 phase increased from 11 nm to 60 nm as the deposition time increased from 2 hrs to 3.5 hrs. The scanning electron microscopic images revealed crack and pinhole free thin films with uniform and smooth background and few large polygonal grains on the surface. The band gap of the cobalt sulfide thin films decreased from 1.75 eV to 1.3 eV as the deposition time increased from 2 hrs to 3.5 hrs. The photoluminescence (PL) spectra of the films confirmed the emission of ultraviolet, violet, and blue lights. The intense PL emission of violet light at 384 nm had red shifted with increasing deposition time that could be resulted from the increase in the average crystallite size. The FTIR spectra of the films indicated the presence of OH, C-O-H, C-O, double sulfide, and Co-S groups. As the deposition time increased, the electrical resistivity of the cobalt sulfide thin films decreased due to the increase in both the crystallite size and the films’ thickness.

ZnS/glass and CdS/glass single layers and ZnS/CdS and CdS/ZnS heterojunction thin films were deposited by the chemical bath deposition method using zinc acetate and cadmium acetate as the metal ion sources and thioacetamide as a nonmetallic ion source in acidic medium. Na2EDTA was used as a complexing agent to control the free cation concentration. The single layer and heterojunction thin films were characterized with X-ray diffraction (XRD), a scanning electron microscope (SEM), energy dispersive X-ray (EDX), and a UV-VIS spectrometer. The XRD patterns of the CdS/glass thin film deposited on the soda lime glass substrate crystalized in the cubic structure with a single peak along the (111) plane. The ZnS/CdS heterojunction and ZnS/glass single layer thin films were crystalized in the hexagonal ZnS structure. The CdS/ZnS heterojunction thin film is nearly amorphous. The optical analysis results confirmed single band gap values of 2.75 eV and 2.5 eV for ZnS/CdS and CdS/ZnS heterojunction thin films, respectively. The CdS/glass and CdS/ZnS thin films have more imaginary dielectric components than the real part. The optical conductivity of the single layer and heterojunction films is in the order of 10 15 1/s. The optical study also confirmed refractive index values between 2 and 2.7 for ZnS/glass, ZnS/CdS, and CdS/ZnS thin films for incident photon energies between 1.2 eV and 3.8 eV. The surface morphology studies revealed compacted spherical grains covering the substrate surfaces with few cracks on ZnS/glass, ZnS/CdS, and CdS/glass and voids on CdS/ZnS thin films. The EDX result confirmed nearly 1 : 1 metallic to nonmetallic ion ratio in the single-layered thin films and the dominance of Zn ion over Cd ion in both ZnS/CdS and CdS/ZnS heterojunction thin films.

Polymeric prodrug-based delivery systems have been extensively studied to find a better solution for the limitations of a single drug and to improve the therapeutic and pharmacodynamics properties of chemotherapeutic agents, which can lead to efficient therapy. In this study, redox-responsive disulfide bond-containing amphiphilic heparin&ndash, chlorambucil conjugated polymeric prodrugs were designed and synthesized to enhance anti-tumor activities of chlorambucil. The conjugated prodrug could be self-assembled to form spherical vesicles with 61.33% chlorambucil grafting efficiency. The cell viability test results showed that the prodrug was biocompatible with normal cells (HaCaT) and that it selectively killed tumor cells (HeLa cells). The uptake of prodrugs by HeLa cells increased with time. Therefore, the designed prodrugs can be a better alternative as delivery vehicles for the chlorambucil controlled release in cancer cells.

A novel monomer based, controlled enzymatic polymerization was employed to produce an engineered alpha-1,3 glucan polysaccharide. The structure and material properties of the engineered polysaccharide were characterized using various techniques. The use of such engineered polysaccharide as a reinforcing filler of polymers was evaluated using model polymers. For this, the alpha-1,3 glucan was incorporated into ethylene vinyl acetate co-polymer (EVA) matrices with vinyl acetate content of 32% and 40% via a melt processing fabrication process. Various mechanical and rheological properties of the fabricated composites were evaluated. The effect of vinyl acetate content of the EVA resin on the interaction with alpha-1,3 glucan that result in various performances attributes was also investigated and reported. The incorporation of alpha-1,3 glucan in these EVA composites resulted in the improvement of key composite properties, such as toughness, modulus, wear resistance, and hardness showing the reinforcing potential of these engineered polysaccharides.

The recent discovery of small interfering RNAs (siRNAs) has opened new avenues for designing personalized treatment options for various diseases. However, the therapeutic application of siRNAs has been confronted with many challenges because of short half-life in circulation, poor membrane penetration, difficulty in escaping from endosomes, and insufficient release into the cytosol. To overcome these challenges, we designed a diethylenetriamine (DETA)- and tetraethylenepentamine (TEPA)-modified polyamidoamine dendrimer generation 4.5 (PDG4.5), and characterized it using 1H nuclear magnetic resonance (NMR), 13C NMR, correlation spectroscopy (COSY), heteronuclear single-quantum correlation spectroscopy (HSQC), and Fourier transform infrared (FTIR) spectroscopy followed by conjugation with siRNA. The PDG4.5-DETA and PDG4.5-TEPA polyplexes exhibited spherical nanosize, ideal zeta potential, and effective siRNA binding ability, protected the siRNA from nuclease attack, and revealed less cytotoxicity of PDG4.5-DETA and PDG4.5-TEPA in HeLa cells. More importantly, the polyplexes also revealed good cellular internalization and facilitated translocation of the siRNA into the cytosol. Thus, PDG4.5-DETA and PDG4.5-TEPA can act as potential siRNA carriers in future medical and pharmaceutical applications.

In a malignant tumor, overexpression of pro-angiogenic factors like vascular endothelial growth factor (VEGF) provokes the production of pathologic vascular networks characterized by leaky, chaotically organized, immature, thin-walled, and ill-perfused. As a result, hostile tumor environment would be developed and profoundly hinders anti-cancer drug activities and fuels tumor progression. In this study, we develop a strategy of sequential sustain release of anti-angiogenic drug, Bevacizumab (BVZ), and anti-cancer drug, Doxorubicin (DOX), using poly ( d , l -Lactide)- Poly (ethylene glycol) -Poly ( d , l -Lactide) (PDLLA-PEG-PDLLA) hydrogel as a local delivery system. The release profiles of the drugs from the hydrogel were investigated in vitro which confirmed that relatively rapid release of BVZ (73.56 ± 1.39%) followed by Dox (61.21 ± 0.62%) at pH 6.5 for prolonged period. The in vitro cytotoxicity test revealed that the copolymer exhibited negligible cytotoxicity up to 2.5 mg ml−1 concentration on HaCaT and HeLa cells. Likeways, the in vitro degradation of the copolymer showed 41.63 ± 2.62% and 73.25 ± 4.36% weight loss within 6 weeks at pH 7.4 and 6.5, respectively. After a single intratumoral injection of the drug-encapsulated hydrogel on Hela xenograft nude, hydrogel co-loaded with BVZ and Dox displayed the highest tumor suppression efficacy for up to 36 days with no noticeable damage on vital organs. Therefore, localized co-delivery of anti-angiogenic drug and anti-cancer drug by hydrogel system may be a promising approach for enhanced chemotherapeutic efficacy in cancer treatment.

Starch is an attractive biomacromolecule for functional materials due to its renewability, biodegradability, amenability for modification, and biocompatibility in mammalian cell lines. In this research, starch was proposed as a modular platform to produce antimicrobial polymer surfaces. Conjugation of biocidal molecules via chemical grafting onto starch (starch-g-biocide) and its antimicrobial properties in poly (lactic acid) (PLA) polymers were investigated. Polyhexamethylene guanidine hydrochloride (PHGH) was synthesized and used as an antimicrobial agent. The grafting was confirmed by FTIR, proton NMR, and elemental analysis. The modified starch was then incorporated into the PLA films at various concentrations, and the antimicrobial efficacy of these films were evaluated against a Gram-positive bacterium, Bacillus subtilis and a Gram-negative bacterium, Escherichia coli. The results showed that the polymer surfaces have high antimicrobial potency when bacteria contact them. This material therefore has great potential for self-decontaminating surfaces, such as medical devices and food packaging applications.

Nitric acid vapor phase oxidation of multi-walled carbon nanotubes (MWCNTs) was proposed as a promising technique to fabricate poly styrene-co-acrylonitrile (SAN)-grafted-CNTs via atom transfer radical polymerization (ATRP). The in-situ ATRP grafting approach was successfully employed to graft polystyrene (PS), SAN and polyacrylonitrile (PAN), onto the convex surfaces of pristine MWCNTs (PCNT) and acid-functionalized MWCNTs (FCNT). Fourier transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance (1H-NMR), and thermogravimetric analysis (TGA) confirmed the effectiveness of the modification via the ATRP grafting approach. The molar composition of acrylonitrile in the synthesized copolymer on the surface of CNTs for an FCNTs was calculated to be about 80% and 67.5% by 1H-NMR and TGA respectively, whereas the value is lower for PCNTs. Morphological studies showed that SAN-grafted FCNTs exhibit rougher surface morphology compared to the SAN-grafted PCNTs. Moreover, the higher diameter of the FCNTs indicated the higher polymer content, which was coated onto CNTs functionalized by vapor-phase oxidation. Therefore, the vapor phase oxidation strategy employed in this study could be utilized as a general method to prepare CNTs which can serve as an ATRP macroinitiator for the fabrication of various polymer grafted CNTs.

As severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission by fomites is one of the main concerns of coronavirus disease 2019, the World Health Organization advised on the use of protective gloves for handling contaminated surfaces and fomites. The shortage in the supply of personal protective equipment (PPE) due to the surging demand in conjuncture with the disposal of an unprecedented quantity of contaminated PPE into the landfill led to an interest for alternative platforms for the management of PPE. In this study, we evaluated the potential of reusing gloves after repeated disinfection cycles using six readily available and common sterilization methods: UV, ethanol, heat, steam, bleach, and quaternary ammonium compounds (quats) for the inactivation of SARS-CoV-2. For this, two commercially available medical-grade gloves, i.e. nitrile and vinyl (polyvinyl chloride) gloves were tested. Both types of gloves showed deterioration in mechanical and thermal performance with the use of quats as sterilization treatment while no remarkable change in properties was observed up to 20 cycles of disinfection for the other sterilization methods. The exceptions were that the vinyl and nitrile gloves did not tolerate steam/dry heat and UV treatment over 10 cycles due to likely dehydrochlorination and thermal degradation, respectively. Subsequent rounds of sterilization caused no significant change in the glass transition temperature (Tg) of either medical gloves; however, quats caused a slight reduction in Tg due to its plasticizing effect. Overall, the physical sterilization treatments including steam, dry heat, and UV allowed the gloves to retain their thermomechanical performance up to ten cycles of sterilization.

Localized cancer therapy with combination of drugs is an effective treatment modality which increase inhibition of tumor growth and reoccurrence. Recently, hydrogels that can encapsulate more than one drug for local sustain releases have been emerging as a compelling choice. In this study, DOX-loaded DMXAA conjugated mPEG-PLGA micelle (DOX-mPPD) was encapsulated in thermosensitive hydrogel prepared by blending carboxylic and amine terminal PDLLA-PEG-PDLLA copolymers and locally injected into tumor-bearing mice to assess the synergistic anti-vascular and immuno-chemotheraputic effects of DMXAA and DOX. The successful synthesis of the copolymers was confirmed by 1HNMR, APC, DOSY and UV spectroscopies. DOX loading capacity of mPPD micelle was relatively higher (6.79%) than mPEG-PLGA (mPP) micelle (6.09%). The cumulative releases of DOX and DMXAA from mPPD micelle at pH 5.5 were 77.34 ± 2.23% and 23.12 ± 0.9%, respectively upon 120 h. The release of DOX and DMXAA from the hydrogel was occurred in a sustained and sequential fashion with a cumulative release of 60.27 ± 87% and 44.55 ± 0.23%, respectively for 40 days. The in vitro cytotoxicity test against MDCK and HeLa cells verified the biocompatibilities of the copolymers for in vivo applications. More importantly, after a single intratumoral injection of various drug formulations into tumor bearing nude mice, hydrogel loaded with DOX-mPPD displayed the highest tumor suppression efficacy, lowest tumoral micro vessel density and increased serum TNF-α and IFN-β upon five weeks. Furthermore, histological analysis of major organs and body weight changes indicated that hydrogel based localized treatments didn’t cause significant systemic toxicities. Therefore, localized co-delivery of DOX and DMXAA with sequential release using hydrogels may be a promising approach for synergistic tumor suppression with minimal adverse effects.

This paper reports the use of cellulose nanocrystals (CNCs) and nanoclays as reinforcing fillers in starch ester (StE) films. The StE was prepared by a one-step homogenous esterification reaction to obtain a degree of substituted hydroxyl moieties of 2.8. StE films with varying concentrations (0, 0.5 wt.%, 1.5 wt.%, 3 wt.%, and 5 wt.%) of CNC and nanoclay were then fabricated using a solvent casting process and characterized using scanning electron microscopy, optical spectrometry, water absorbance, water vapor permeability, mechanical tests, and simulated compostability studies. The SEM images for the CNC-filled composites revealed aggregates of CNC in the matrix, while nanoclay showed a homogeneous dispersion. Although no apparent visible change in transparency was observed for all filled films, a decrease in light transmission was revealed by optical density measurements. The incorporation of the nanofillers improved the yield strength of the starch-ester films significantly. This improvement in the tensile strength was as much as 112 % and 173 % for 5 wt. % of CNC and 5 wt.% of nanoclay, respectively. No hydrolysis was observed for StE under the simulated composting conditions over six months. Compared to the unfilled StE films, the reinforced films showed a reduction in weight approximately equal to the amount of the filler, with a maximum degradation of 8.9 wt.% for the 5 wt. % nanoclay filled StE films.

A stiff, hydrophobic, and corrosion protective polyurethane (PU) nanocomposite coatings have been fabricated via the incorporation of surface modified cellulose nanocrystals (CNC). The modification of CNC involves surface grafting of varying levels of epoxy functionalized silane (ES). The effect of reaction time and concentration of ES on the level of grafting were evaluated using Fourier Transform Infrared Spectroscopy (FTIR), Elemental analysis (EA), X-ray photoelectron spectroscopy (XPS), water contact angle measurement (WCA) and dispersibility test. It was found that prolonged reaction time and the high mole ratio of ES to CNC improve thermal properties and material wettability of the modified CNC. The incorporation of modified CNC in PU not only improved thermomechanical properties but also reduced the water absorption properties of the PU composites, which could be attributed to the improvement in the dispersion and enhanced interfacial adhesion between the nanoparticle and the PU matrix. Salt spray and electrochemical impendence spectroscopy (EIS) studies, which were carried out on mild steel coated with the fabricated nanocomposite (PU/ES-CNC), exhibited better anticorrosion behaviors as compared to PU. Overall, the CNC modification through silanization is a robust, eco-friendly, and scalable process, making it an appealing material for a range of polymer composite applications.

Teff is a unique staple food in Ethiopia. Teff has not been investigated in detail with respect to biofilm base material. In this study, a biofilm was prepared using teff-starch. Further, water barrier, mechanical, and optical properties of the teff-starch based films were investigated. These properties were compared with the cassava-starch based biofilm that was developed with same combination of plasticizer, surfactant and agar. The result showed that teff-starch based edible film is good compactable for food packaging material. Also, the mechanical and optical properties compared with standard cassava-starch based biofilm showed teff-starch films are better appropriate as for a packaging material.

Poly(lactic acid) (PLA) was employed as wood fiber (WF) binder to fabricate thin-structured biocomposites via solvent-blending process and compression molding, with 50 to 80 wt.% WF contents. Also, adhesion improvement between the WF via enhanced wood fibers wetting with maleated PLA was employed. Overall, the mechanical properties of WF-PLA-MA biocomposites were improved in comparison to those of the WF-PLA. At higher WF loading, the strength was maintained for WF-PLA-MA while it reduced for WF-PLA. At 50 wt.% WF loadings, the storage modulus increased by 29% and the tan delta peak shifted to a higher temperature for the WF-PLA-MA as compared to those of the WF-PLA. Improved water-resistant of WF-PLA-MA, substantiated by a 7–17% reduction in thickness swelling of the sheets was observed as compared to WF-PLA. Overall, the thin-structured and highly filled wood-plastic composite presented appealing material properties for a range of applications including compostable crates, thermo-formable sheets for single use food utensil production etc.

Polypropylene (PP) and low-density polyethylene (LDPE) are among the most converted resins; as such, they also have the largest share in municipal waste fractions. Currently, there is a great societal and industrial need to recycle these polymers using thermo-mechanical processes. However, process-induced degradation during recycling operations may lead to irreversible changes. In this study, PP was blended with 0 to 10 wt.% of LDPE was subjected to consecutive twin-screw extrusion cycles (0 to 5 times) to mimic thermo-mechanical recycling. The effect of reprocessing on the rheological, thermal, and mechanical properties of PP/LDPE blends was investigated. An increase in MFR and decrease in viscosity was observed for PP and the blends. DSC results showed that the crystal structure of PP was seriously affected and generated more disorder with reprocessing. Although tensile properties were not substantially affected, all properties had a decreasing trend. While successive thermo-mechanical processing caused chain scission of the PP phase of the blend, the overall property of the studied blend composition maintained acceptable properties. Thus, recycling of PP with low PE blend additive is a feasible option not only to reduce plastic waste but also to generate value from an otherwise waste product.