About

Dr. Saad Khan is an INVISTA Professor in the Department of Chemical and Biomolecular Engineering at North Carolina State University. His contact information includes a phone number (919-515-4519) and email address (khan@ncsu.edu). He is associated with the Khan Research Group, which is part of the university's research community. The page indicates his role as a principal investigator and his affiliation with the university's engineering department, but does not provide additional details about his research focus, background, or key contributions.

Research topics

• Nanotechnology
• Materials science
• Composite material
• Computer Science
• Chemical engineering
• Environmental science
• Biology
• Natural resource economics
• Ecology
• Environmental resource management
• Agroforestry
• Economics
• Engineering
• Business
• Environmental planning
• Environmental protection
• Biotechnology
• Optoelectronics
• Polymer chemistry
• Physics
• Agronomy
• Optics
• Environmental economics
• Agricultural engineering

Selected publications

• “Wrap and Plant” Seed Treatment: A Sustainable Management Practice for Yield Improvement and Storability of Yam Against Plant‐Parasitic Nematodes in Ghana

  International Journal of Agronomy · 2026-01-01

  articleOpen access

  Yam is an important food and income security crop for people in Ghana. Plant‐parasitic nematode infestation in soils and seed yams is a hindrance to peak production and profitability of the yam business. The key yam nematodes are Scutellonema bradys , Meloidogyne spp., and Pratylenchus spp., which cause dry rot in yam in the field, and in storage resulting in tuber losses. This study evaluated the efficacy and yield potential of abamectin “wrap and plant” technology in the management of plant‐parasitic nematodes in yam production in comparison with the traditional method in three agroecological zones in Ghana. The experiment was conducted over two seasons across three locations (Krachi‐Nchumuru, Zabzugu, and Nkoranza) in Ghana, using a randomized complete block design with four replications. Field trials were set up in both wet (March–May) and dry (November–February) seasons for Nchumuru and Zabzugu districts with the exception of Nkoranza district, which had only a dry season field trial. Treatments involved banana paper with abamectin (treatment A), banana paper only (Treatment B), and farmer’s practices (FPs). Nematode damage severity after 5 months of yam storage for treatment A was the least (2.21, 3.78, and 4.60) for Krachi‐Nchumuru, Zabzugu, and Nkoranza districts, respectively. There were no significant differences among the various treatments for the initial and final nematode populations, and all treatments had reproductive factors (Rf) less than 1. Treatment A further had the least yam weight losses (29.79%, 30.18%, and 68.12%) after 5 months of storage for Krachi‐Nchumuru, Zabzugu, and Nkoranza districts, respectively. Yam weight losses in Legon storage environments were slightly lower than those in the other storage environments due to lower relative humidities in these barns. Abamectin‐treated banana paper has the potential to reduce yam rot and nematode population build‐up in yams placed in storage.

  PublisherOA PDFDOI

• Existing Research on Pretreatment Techniques, Preparation, Compatibility, and Performance of Crumb Rubber Modified Asphalt

  International Journal of Pavement Research and Technology · 2026-01-03

  article
  PublisherDOI

• Using Supercritical CO₂ for Viscosity Reduction of Polymers: A Data-Driven Modeling Approach for Predicting the Diffusive Properties of Polystyrene Melt

  Industrial & Engineering Chemistry Research · 2025-08-12 · 2 citations

  articleSenior authorCorresponding

  This study investigates the influence of supercritical CO2 on the rheological properties of polystyrene (PS) through a comprehensive rheological analysis. By generating time-dependent viscosity curves and the corresponding torque profiles, we accurately assess the progressive plasticization effects of CO2. Results show that CO2 can significantly lower the viscosity of PS, achieving up to a 96% reduction when transitioning from atmospheric to subcritical conditions and an additional 56% decrease when moving from subcritical to supercritical states. These findings highlight the effectiveness of supercritical CO2 in enhancing the processability of polymers through viscosity reduction. Furthermore, we develop a universal viscosity model that incorporates temperature, shear rate, and CO2 concentration effects for PS-CO2 melts. This model in combination with CO2 solubility models offers a robust framework for accurately predicting CO2 diffusion coefficients. This methodology not only deepens our understanding of CO2–PS interactions but also provides a reliable tool for future research and industrial applications, presenting a more efficient and environmentally friendly alternative to traditional methods.

  PublisherDOI

• Tailored Oxides for CO₂ Capture and Enzyme Confinement/Immobilization

  SSRN Electronic Journal · 2025-01-01

  preprintOpen accessSenior author
  PublisherDOI

• Diet links gut chemistry with cancer risk in C57Bl/6 mice and human colorectal cancer patients

  bioRxiv (Cold Spring Harbor Laboratory) · 2025-01-28

  preprintOpen access

  Background & Aims Western-style diets, characterized by higher fat and protein, and low micronutrient levels, promote the development of colorectal cancer (CRC). Here, we investigate the role of a Western diet on microbiome composition, sulfide production, and intestinal epithelial damage in pre-CRC mice, and validate taxonomic changes in a meta-analysis of human CRC patients. Methods NWD1 is a purified Western-style diet that produces sporadic intestinal and colon tumors in wild-type C57BL/6 mice in the absence of genetic or carcinogen exposure. To determine how this diet influences cancer risk by shaping microbial composition and sulfide chemistry, mice were fed NWD1 or a purified control diet for 24 weeks. Microbiome composition, sulfide production, and intestinal stem cell mRNA expression were assessed. Observed microbiome changes were validated in a human CRC meta-analysis. Results Fecal sulfide levels were tripled in NWD1-fed mice ( P< 0.00001 ), concurrent with increased abundance of the sulfidogenic Erysipelotrichaceae family. NWD1-fed mice had increased expression of mitochondrial sulfide oxidation genes in Lgr5 hi intestinal stem cells, demonstrating an adaptive response to elevated sulfide. In a meta-analysis of human CRC studies, we observed that Erysipelotrichaceae were associated with CRC, validating both canonical CRC microbes such as Solobacterium moorei and highlighting the potential contribution of previously unrecognized, disease-associated microbes. Conclusions Our analyses connect the risk factors of Western diet, sulfide, and epithelial damage in a pre-cancer mouse model to microbiome changes observed in human CRC patients and suggest that microbial signatures of CRC and gut ecosystem alteration may manifest long before disease development.

  PublisherOA PDFDOI

• Metal Organic Framework Impregnated Nanofibrous Aerogels: A 3D Structured Matrix for CO₂ Capture

  ACS Applied Materials & Interfaces · 2025-04-17 · 5 citations

  articleSenior authorCorresponding

  This study explores the synthesis and functionality of mesoporous UiO-66-NH2 metal–organic framework (MOF) impregnated cellulose diacetate (CDA)-silica hybrid nanofibrous aerogels (NFAs) for selective CO2 capture. Mesoporous MOFs generally outperform microporous MOFs for CO2 capture, while NFAs provide a lightweight, highly porous material platform consisting of a three-dimensional (3D) network of interlinked nanofibers, offering both mechanical strength and a larger surface area. We exploit the attributes of these candidate materials by producing CDA-silica@UiO-66-NH2 NFA through a simple freeze-drying process involving a mixture of CDA-silica nanofiber dispersions and mesoporous UiO-66-NH2 nanoparticles in tert-butanol, avoiding cumbersome pre- or postprocessing typical in aerogel synthesis. The aerogels exhibit a hierarchical porous structure, allow for MOF loadings of up to 80 wt %, and demonstrate remarkable CO2 adsorption performance, with a direct correlation between MOF content and adsorption efficiency. Notably, an NFA containing 80 wt % MOF achieves a CO2 uptake of 2.5 mmol/g at 35 °C and atmospheric pressure. The CDA-silica@UiO-66-NH2 NFA also exhibits a strong preference for CO2 adsorption compared to N2 across all pressure levels when exposed to a gas mixture of CO2 and N2 in an 85:15 ratio. The CO2/N2 selectivity (Sads) usually calculated by using the ideal adsorption solution theory (IAST) reveals a value of 18.2 at 298 °K for this system. The NFA also displays strong mechanical resiliency including compressibility and fatigue resistance, and MOF integration without detachment during multiple compression cycles. Unlike traditional CO2 capture materials, our CDA-silica@UiO-66-NH2 NFA with a combination of high CO2 selectivity, structural integrity, and ease of fabrication thus offers a potentially scalable solution that addresses both performance and durability in real-world applications.

  PublisherDOI

• Durable Physically Mixed Microporous and Mesoporous MOFs/Nanofiber Aerogel 3D Composites for Effective Toxic Gas Capture and Organophosphonate Detoxification

  Advanced Functional Materials · 2025-09-20 · 3 citations

  article

  Abstract There is a critical need for innovative materials that offer efficient chemical filtration and detoxification of organophosphonates (OPs), pesticides, and other toxic industrial gases. In this study, a versatile method is introduced for fabricating 3D hierarchically porous mechanically stable nanofibrous aerogel (NFA)‐MOF composites with MOF mass fraction exceeding 80 wt.%, designed for enhanced detoxification. Mesoporous Zr‐MOF (UiO‐66‐NH 2 ), synthesized through a mild solvothermal process with cocamidopropyl betaine (CAPB) surfactant as a template, is combined with PAN/PVP nanofibrous dispersions to create composite NFAs. By adjusting CAPB concentration, MOF mesoporosity is tuned, achieving a maximum surface area of 1000 m 2 g −1 with 0.5 g CAPB. Composites containing UiO‐66‐NH 2 show effective hydrolysis of the DMNP simulant and degradation of chemical warfare agents (CWAs) such as soman (GD) and sulfur mustard (HD). The versatile mixing strategy is extended to incorporate microporous MOFs such as HKUST‐1 to enhance NFA functionality. Composites with HKUST‐1 effectively adsorb ammonia (NH 3 ), 2‐chloroethyl ethyl sulfide (CEES), and Cl 2 while mechanical and adhesion testing confirm that MOF loadings between 50 wt.% and 80 wt.% maintain excellent mechanical integrity. These multifunctional composite NFA offer significant potential as advanced materials for chemical defense, air purification, and environmental remediation, benefiting from a cost‐effective and environmentally friendly synthesis method.

  PublisherDOI

• Mechanically Robust Mesoporous UiO‐66‐NH₂/Nanofibrous Aerogel for Organophosphonates Detoxification

  Advanced Science · 2025-03-16 · 26 citations

  articleOpen accessCorresponding

  Abstract There is a critical need for novel composite materials for high‐performance chemical filtration and detoxification of organophosphonates (OPs) and other harmful compounds found in nerve agents, pesticides, and industrial processes. In this work, rapid hydrolysis of OPs using high‐surface‐area zirconium‐based MOF‐aerogel composites is demonstrated. Using a unique surfactant‐templated solvothermal synthesis method, mesoporous UiO‐66‐NH 2 grown on the fibers within a polyacrylonitrile (PAN)/polyvinylpyrrolidone (PVP) nanofibrous sponge can produce a 3D MOF–polymer matrix with a specific surface area of up to 900 m 2 g −1 comp —almost 2X larger than the highest previously reported values while maintaining robust mechanical integrity. The mesoporous MOF promotes efficient diffusion, and the aerogel matrix provides a high‐surface‐area platform for spill containment. Unlike activated carbon, which adsorb OPs without degradation, the UiO‐66‐NH 2 ‐sponges hydrolyze OPs upon water contact, significantly reducing their toxicity. The MOF‐aerogel sponges withstand stresses up to 40 kPa under 70% strain are shown while maintaining exceptional catalytic efficiency, achieving a methyl paraoxon degradation half‐life of 3 min, compared to 15 min for similar microporous MOFs. This innovation accentuates the potential of mesoporous Zr‐MOF aerogels for advanced protection, filtration, and catalysis.

  PublisherOA PDFDOI

• Compressing slippery surface-assembled amphiphiles for tunable haptic energy harvesters

  Science Advances · 2025-01-15 · 4 citations

  articleOpen accessCorresponding

  A recurring challenge in extracting energy from ambient motion is that devices must maintain high harvesting efficiency and a positive user experience when the interface is undergoing dynamic compression. We show that small amphiphiles can be used to tune friction, haptics, and triboelectric properties by assembling into specific conformations on the surfaces of materials. Molecules that form multiple slip planes under pressure, especially through π-π stacking, produce 80 to 90% lower friction than those that form disordered mesostructures. We propose a scaling framework for their friction reduction properties that accounts for adhesion and contact mechanics. Amphiphile-coated surfaces tend to resist wear and generate distinct tactile perception, with humans preferring more slippery materials. Separately, triboelectric output is enhanced through the use of amphiphiles with high electron affinity. Because device adoption is tied to both friction reduction and electron-withdrawing potential, molecules that self-organize into slippery planes under pressure represent a facile way to advance the development of haptic power harvesters at scale.

  PublisherDOI

• Janus layered nanofibrous aerogels with switchable wettability for targeted emulsion separation

  Chemical Engineering Journal · 2025-02-21 · 9 citations

  articleOpen accessSenior authorCorresponding

  • Solid-templating of nanofibers into functional aerogels. • Stratified aerogels of hydrophobic and oleophilic layers enable oil–water separation. • Gravity-driven emulsion separation with >95 % efficiency over multiple cycles. • Surface energy model supports experimental separation/sorption findings. • a priori prediction for solvent sorption that could be pertinent in chemical spills. This study introduces an innovative bioinspired bilayered nanofibrous aerogel (NFA) fabrication approach to create asymmetric porosity and wettability in mechanically robust aerogels without the use of complicated processing steps and harsh chemical modifiers. Combining cellulose acetate-silica (CA-Sil) and polyacrylonitrile/polyvinylpyrrolidone (PAN/PVP) nanofiber layers, the hybrid NFA is assembled via a directional layer-by-layer freezing technique, resulting in a mechanically robust, 3D hierarchical porous structure. To provide responsive functionality, we also embed magnetic iron oxide (Fe 3 O 4 ) nanoparticles in the PAN/PVP nanofibers. The CA-Sil layer is hydrophobic (water contact angle (WCA) 129°), while the PAN/PVP-Fe layer is amphiphilic, enabling efficient, gravity-driven emulsion separation with over 95% removal efficiency across multiple cycles without significant loss of performance. Further insights into NFA’s selective sorption of various solvents, is obtained by examining its wettability through surface energy calculations using Zisman’s theory and Fowkes’ model validated by experiments. The surface energy values of 52.5 mN/m and 72.38 mN/m shown for the CA-Sil and PAN/PVP-Fe layers respectively corroborate selective permeability/separation, introducing a robust approach for emulsion separation. These layered NFAs with controlled selectivity establish a versatile framework for sustainably developing Janus porous materials using hybrid nanofibers meeting critical needs for tailored performance in diverse applications.

  PublisherDOI

Frequent coauthors

• Orlando J. Rojas

  University of British Columbia

  67 shared

• Richard J. Spontak

  North Carolina State University

  61 shared

• Srinivasa R. Raghavan

  University of Maryland, College Park

  32 shared

• Peter S. Fedkiw

  29 shared

• Anurodh Tripathi

  28 shared

• Tahira Pirzada

  26 shared

• Joseph M. DeSimone

  L V Prasad Eye Institute

  25 shared

• Bor‐Sen Chiou

  Western Regional Research Center

  24 shared

Labs

• Khan Research GroupPI

  1-2 sentence research focus

Education

• Ph.D., Chemical Engineering

  Massachusetts Institute of Technology

  1985

• BSE, Chemical Engineering

  Princeton University

  1980