Search

The velocity data presented demonstrate the complicated flow behavior of nanocrystalline cellulose (NCC) suspensions even when standard rheometry shows only subtle effects. Rheo-nuclear magnetic resonance (NMR) velocimetry with spatial and temporal resolution indicates that NCC suspensions undergo varying flow behavior, which correlates with bulk rheology and includes wall-slip, shear banding, and yielding. Large-velocity fluctuations in a chiral nematic liquid crystal-phase suspension (5% w/v) indicate particle director orientation tumbling and flow. The results provide details of the mesoscale velocity distributions in space and time, which can be used to inform the interpretation of rheology data, as well as processing flow conditions to control NCC suspension microstructure and impact properties of composite and other materials.

Cellulose nanomaterials (CNMs) naturally exist in biomass. Recent developments in nanotechnology and extraction procedure of CNMs open up a new era in the polymer composites industry. Abundant, renewable, biodegradable, transparent, light weight, and most importantly, low cost make CNMs the ideal material for packaging, automotive, construction, and infrastructure applications. CNMs are generally used as materials for polymer matrix reinforcement in the composites industry. The industrial-scale manufacturing of CNM/thermoplastic composites remains an unsolved puzzle for both academics and industries. The dispersion of nanocellulose in polymer matrix is the central problem inhibiting the manufacturing of CNM/polymer composites at an industrial scale. Several attempts were made to disperse nanocellulose effectively in a polymer matrix and improve compatibility between the matrix and CNMs. Chemical-aided surface modification of CNMs has been effective in several cases; however, chemical toxicity, high price, and critical control of reactions make them unsuitable. This current review paper focuses on novel eco-friendly physical dispersion techniques of CNMs and their future scope of research. The physical dispersion techniques such as plasma-induced surface modification, ultrasonication, magnetic and electric field discharge, electrospinning, or drawing can visibly improve the dispersion state of CNMs. But several factors affect physical techniques’ performance, e.g. CNM type and forms, process conditions and parameters, etc. Moreover, the material-related factors interplay with the process-related factors. This review addresses the current state of knowledge on the physical dispersion techniques for CNMs and identifies challenges that are critical to adoption of these novel materials at commercial scale for future applications.

Lentil puffs were developed from a mixed design of varying weight fractions of lentil flour (x1), lentil starch concentrate (x2), and lentil protein concentrate (x3) using a twin‐screw pilot scale extruder at a dry feed rate of 20 kg/h (d.b.), a water feed rate of 2 kg/h, and an extruder screw speed of 350 rpm. Evaluations of the extrudate properties (expansion ratio, unit density), instrumental texture (hardness, crunchiness, and crispiness), and sensory properties (overall and texture liking, just about right (JAR), and check all that apply (CATA) were conducted, and the optimum lentil puff formulation was determined from sensory liking. Increasing x1 and x2 both increased the expansion ratio of the lentil puffs, whereas the interactions of x3 with x1 and x2 both reduced the unit density. All three formulation factors positively impacted the instrumental crunchiness and crispiness of the lentil puffs, whereas x3 had a larger impact on crunchiness, and x1 and x2 had a larger impact on crispiness. Lentil puff formulations with x3 ≥ 0.66 presented significantly lower sensory liking scores than those with x2 ≥ 0.33. The JAR test revealed that all lentil puff formulations were penalized for not having the right level of hardness, whereas the CATA test identified the crispy and crunchy attributes to positively correlate with overall and texture liking scores. The optimum lentil puff formulation was predicted from a maximum overall liking score of 6.1 and texture liking score of 6.7, to contain 50% (w/w, d.b.) of lentil starch concentrate and 25% of both lentil flour and lentil protein concentrate. [ABSTRACT FROM AUTHOR]

Polyethylene (PE) mulches are widely used in strawberry (Fragaria × ananassa Duch) production for weed suppression and crop growth optimization. However, PE mulches are not biodegradable and contribute to plastic pollution. Our objective was to develop and test biodegradable liquid-applied 'hydromulches' (HMs) as a sustainable alternative to PE mulch. HM weed suppression efficacy, strawberry plant growth, and yield were evaluated. HMformulations consisted of shredded newsprint paper (NP), water, and a tackifier, either guar gum (GG) or psyllium husk (PH) added at 2 or 6%. Experiments were conducted at two environmentally distinct locations: northwest Washington (WA) and eastern North Dakota (ND). Five HM formulations were compared to black PEmulch within a randomized complete block design with four replications. PEmulch suppressed weeds completely at peak weed emergence and peak weed vegetative growth at both locations. Formulations of HM containing GG provided superior weed suppression compared to other HM formulations at peak weed emergence (4-6 vs. 18-22 plants m-2, respectively). At peak vegetative growth, HM formulations containing GG had the lowest weed density compared to other HMs in ND (1 vs. 9-12 plants m-2), whereas these differences were not observed in WA. Total weed biomass did not differ among HMs across both locations. GG HM formulations deteriorated similarly to PE mulch (3-5% vs. 2%, respectively) in ND, whereas other HMs deteriorated more substantially. In WA, all HMs deterioratedmore than PEmulch (6-12% vs. 1%, respectively). Fruit yield did not differ among treatments inweedy and weed-free subplots (194-254 g plant-1) inWA. In ND, yield was greater in all HM treatments compared to PE mulch in both weedy andweed-free subplots. Across both locations, strawberry canopy coverwas greater in PE mulch (56.1% canopy cover) compared to 2%GG and NP (42.4 and 39.8% canopy cover). Strawberry plant biomass was similar among mulch treatments. However, strawberry leaf and crown biomass were slightly lower in 2%PH compared to other mulch treatments. Results demonstrate HMs with GG tackifier are a promising alternative to PE mulch in organic strawberry systems based on ability to suppress weeds, enhance strawberry growth, and maintain yield. [ABSTRACT FROM AUTHOR]

The widely used high-density polyethylene (HDPE) polymer has inadequate mechanical and thermal properties for structural applications. To overcome this challenge, nano zinc oxide (ZnO) and nano boron oxide (B2O3) doped lignin-containing cellulose nanocrystals (L-CNC) were blended in the polymer matrix. The working hypothesis is that lignin will prevent CNC aggregation, and metal oxides will reduce the flammability of polymers by modifying their degradation pathways. This research prepared and incorporated safe, effective, and eco-friendly hybrid systems of nano ZnO/L-CNC and nano B2O3/L-CNC into the HDPE matrix to improve their physio-mechanical and fire-retardant properties. The composites were characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive X-ray analysis, thermo-gravimetric analysis, differential scanning calorimetry, dynamic mechanical analysis, horizontal burning test, and microcalorimetry test. The results demonstrated a substantial increase in mechanical properties and a reduction in flammability. The scanning electron microscope (SEM) images showed some agglomeration and irregular distribution of the inorganic oxides. [ABSTRACT FROM AUTHOR]