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While the relative abundance of plant biopolymers can vary significantly depending on the cell type and maturation, pectin and cellulose nanocrystals are among the two key biopolymers found in many plants’ primary cell walls at the early growth stage. Nanocomposites that utilize cellulose nanocrystals have gained extensive interest over the years. Limited knowledge regarding pectin and the interaction between pectin and cellulose is available because pectin was considered a non-loading-bearing component with little interaction with cellulose. However, recent developments in primary cell wall structure have shifted, and pectin is viewed as a part of the reinforcement structure. Thus, understanding the role of pectin has become relevant in creating advanced bio-composites that mimic the structure of primary cell walls. This work aims to provide fundamental information on the interaction between pectin and cellulose nanocrystals using molecular dynamics simulations. A dry interaction is modeled to replicate their status in a composite, where water is removed via processing such as freeze-drying. Interphase models consisting of two cellulose nanocrystals and a homogalacturonan pectin molecule are created to simulate the interfacial structure, including binding potential energy and hydrogen bonds. Friction and adhesion responses are predicted by moving one cellulose nanocrystal against the other. The results show that a pectin molecule increases the friction at the interphase by 14 and 8 times between CNC (200) and (110) surfaces, respectively, which is correlated to the significantly increased binding energies and interfacial hydrogen bonds, regardless of pectin’s charge density. On the other hand, the adhesion force is increased by 1.1 times with a pectin molecule between the CNC (110) surfaces. Adhesion, however, reduces to 1/5 between CNC (200) surfaces with embedded pectin, which is attributed to disrupted$$\pi$$ $\pi$-$$\pi$$ $\pi$interaction. The simulation results reveal the atomistic level interaction between pectin and cellulose nanocrystals, which is essential for designing nanocomposites using pectin and cellulose nanocrystals as main components. 

The global spread of Fall Armyworm (FAW, Spodoptera frugiperda) has posed significant challenges to crop productivity and food security, with current pest management relying heavily on synthetic pesticides. This study explores the green synthesis of neem extract and neem oil-based Azadirachtin nanopesticides using cellulose acetate (CA) as a carrier polymer, focusing on their efficacy against FAW. The objective was to assess whether CA-NEP (neem extract nanopesticides) and CA-NOL (neem oil nanopesticide) formulations were effective at FAW control with minimal ecological impact. The nanopesticides were synthesized by electrospinning at concentrations of 5 %, 10 %, 20 %, 33 %, and 50 % (w/w) and characterized using Scanning Electron Microscopy and Fourier Transform Infrared spectroscopy. Azadirachtin content was quantified using Liquid Chromatography-Mass Spectroscopy. CA-NEP and CA-NOL followed first-order, and Korsmeyer-Peppas release kinetics, respectively. Feeding bioassays showed high FAW mortality rates, with 20 %-50 % CA-NEP achieving greater than 40 % mortality in less than 3 days and 50 % CA-NEP reaching 100 % mortality by day five. The mortality rates of FAW due to feeding on CA-NOL-treated corn leaves reached 40 % after 4 and 6 days, respectively, for 50 % and 33 % CA-NOL. Placing nanopesticide fibers next to corn seeds during planting significantly reduced FAW leaf damage. The lethal dose 50 (LD50) analyses showed that 13 % CA-NEP is the optimal concentration for FAW control. Environmental safety assessments on earthworms showed no acute or chronic toxicity, indicating that the nanopesticides suit ecologically sensitive areas. Therefore, these nanopesticide formulations provide a promising, eco-friendly alternative for sustainable FAW control and management with enhanced efficacy and safety. 

The structural integrity of MXene and MXene-based materials is important across applications from sensors to energy storage. While MXene processing has received significant attention, its structural integrity for real-world applications remains challenging due to its flake-like structure. Here the mechanical response of layered MXene-polymer nanocomposites (MPC) with high MXene concentration (>70 %) and bioinspired nacre-like brick-and-mortar architecture is investigated to offer insights for MPC design and processing. An automated finite element analysis (FEA) framework is developed to analyze MPC models with randomized geometries and multiple combinations of the parameter space. Specifically, the influence of concentration, aspect ratio (AR), flake thickness, flake distribution, and interfacial strength is investigated. The results reveal property trends such as increasing elastic modulus, strength, and toughness with increasing cohesive strength and concentration for lower AR (=40, 60) but a decreasing trend at higher AR of 75. Local structural features like flake distribution, overlapping MXene lengths, and interconnected polymers in adjacent layers was found a critical determinant of performance. For example, stronger cohesive interaction showed 6X high toughness (291 226 ) compared to weaker case (50 24 ), but the large scatter highlighted the impact of microstructural features. The results are compared and validated with theoretical, computational, and experimental work. The findings provide valuable guidance for optimizing MPC design and their processing. Finally, the automation of the framework allows the design to be extended beyond the current system and chosen material combinations. 

The electrospinning method is increasingly in demand due to its capability to produce fibers in the nanometer to micrometer range, with applications in diverse fields including biomedical, filtration, energy storage, and sensing. Many of these applications demand control over fiber layout and diameter. However, a standard flat plate collector yields random fibers with limited control over diameter and density. Other viable solutions offering a higher level of control are either scarce or substantially expensive, impeding the accessibility of this vital technique. This study addresses the challenge by designing an affordable laboratory-scale electrospinning setup with interchangeable collectors, enabling the creation of targeted fibers from random, aligned, and coiled. The collectors include the standard flat plate and two additional designs, which are a rotating drum and a spinneret tip collector. The rotating drum collector has adjustable speed control to collect aligned fibers and exhibits stability even at high rotational speeds. The spinneret tip collector was designed to produce helically coiled fibers. The setup was validated by directed fiber formation using polycaprolactone (PCL), a biodegradable and FDA-approved polymer. Overall, the uniqueness of the design lies in its affordability, modifiability, and replicability using readily available materials, thus extending the reach of the electrospinning technique. 

The cell wall (CW) in plants is an anisotropic fiber-reinforced composite material made from multiple components (cellulose, hemicellulose, pectin, and lignin), with their structure and properties varying throughout the growth process to accommodate its multifunctional biological and structural needs. Revealing the architecture of plant CW and the role of its constituent and their interfaces is the key driver for this study. Here we characterized the composite-structure-mechanical response outcome of CW under component removal using enzymatic treatment, followed by instrumented indentation, optical microscopy, and Raman spectroscopy analysis to illustrate the changes. The results of the study indicate the critical role of pectin in the structure, where its breakage f1rom the cell wall leads to a maximum loss in structure and strength both for the early and later stages of plant growth. This study forms the basis of an expanded future investigation into the cell wall structure toward designing flexible fiber-reinforced composites for a broad range of applications.