Particle Size Dispersion Research Articles

Synthesis and Properties of Carbon Microspheres from Waste Office Paper.

As a kind of biomass resource, waste office paper can be used as a carbon precursor to prepare carbon materials. In this work, carbon microspheres with regular shape, uniform particle size and high carbon content were successfully prepared from waste office paper via a hydrothermal synthesis method with sulfuric acid as the catalyst. The effects of reaction temperature and sulfuric acid dosage on the morphology of the carbon microspheres were studied. The formation mechanism of the carbon microspheres was investigated by analyzing the structure and composition of the products. The results show that the hydrolysis of cellulose in waste paper under hydrothermal conditions was the key for the formation of carbon microspheres. The temperature of hydrothermal reaction and the use of sulfuric acid can affect the morphology of carbon microspheres. The carbon microspheres synthesized at 210 °C with 10 mL sulfuric acid have the best surface morphology, with uniform particle size and higher dispersion. Cyclic voltammetry and electrochemical impedance spectroscopy show that the carbon microspheres have good capacitance performance and can be used in capacitors. This study provides a low-cost precursor for carbon microspheres as well as a new method for the recycle of waste paper.

Enzyme-sensitive soybean protein isolate/cinnamaldehyde antibacterial microcapsules triggered by blueberry proteases

In this study, enzyme-sensitive microcapsules using soybean protein isolate as the wall material, and cinnamaldehyde as an antimicrobial core material, were prepared by vacuum freeze-drying. The results showed that a 4% solution of soybean protein isolate with cinnamaldehyde added at a 4:1 (w/w) ratio provided an effective microcapsule formulation, with an embedding rate of 62.63 ± 0.95% and a particle size of 347.00 ± 31.18 nm. After lyze-drying, SPI-CA microcapsules showed uneven morphology, sag and agglomeration, but the microcapsules had small particle size and good dispersion stability. The 4%SPI/CA-4:1 microcapsules provided protection for cinnamaldehyde for 12 days. The release of cinnamaldehyde was slow from the 6th day, and the cumulative release was 79.08 ± 3.0% after 12 days. In addition, infrared spectroscopy, XRD and DSC prove that the hydration of soybean protein isolate, electrostatic repulsion charges, and the creation of cinnamaldehyde essential oil nanodroplets resulted in stable microcapsules. The microcapsules produced were successful in providing the controlled release of its antibacterial substance when exposed to natural protease concentrations triggered by fungal growth on blueberries. The release of cinnamaldehyde from SPia-Ca microcapsules was triggered by protease, which was secreted from blueberry by microbial contamination. The developed microcapsule has wide applications, and the results of this study provide new ideas for future food preservation technology development.

Synthesis of bio‐based modified amphoteric acrylate epoxy emulsion surface sizing agent via RAFT polymerization

AbstractThe synthesis of bio‐based modified amphoteric epoxy modified acrylate sizing emulsion based on reversible addition fragmentation chain transfer (RAFT) polymerization and its application in paper sizing were studied. A macromolecular chain transfer agent for RAFT polymerization was synthesized by the esterification of epoxy resin E‐51 with RAFT agent to eliminate the active groups on RAFT agent. Amphoteric polymer emulsifiers with good emulsification and dispersion effects in acidic and alkaline media were successfully prepared by RAFT polymerization. After neutralization, other monomers were polymerized to access cationic sizing emulsion (acid neutralization) and anionic sizing emulsion (alkali neutralization). The effects of bio‐based monomer content, hydrophilic monomer dimethylaminoethyl methacrylate (DM) content and degree of quaternization on the properties of sizing emulsion and sizing paper were further explored. In addition to the particle size and polymer dispersion index (PDI) of latex particles in different experimental groups, the water resistance, folding resistance, bursting strength, tensile strength and surface roughness of sized paper were analyzed and evaluated. Based on these results, a better sizing emulsion formulation was established. It was confirmed that the addition of bio‐based monomers can improve the sizing performance of paper.

Fabrication of rice bran oil nanoemulsion and conventional emulsion with Mustard Protein Isolate as a novel excipient: Focus on shelf-life stability, lipid digestibility and cellular bioavailability

Proteins are one of the many effective biomolecules found in oilseed meals. In order to formulate an oil-in-water nanoemulsion based lipophilic nutraceutical delivery vehicle for Rice Bran oil (RBO) rich in γ-oryzanol, we used mustard seed meal protein isolate (MPI) as a novel natural surfactant together with a small molecular weight co-surfactant Tween 20 in various ratios (3:1, 1:1, 1:3) to stabilize the heterogeneous system. The oxidative stability, physico-chemical characterization in response to pH and ionic strength, shelf-life, and storage of the nanoemulsions containing 1% surfactant in total, comprising different ratios of MPI and Tween 20 were optimised to form an efficient biphasic surfactant system. The oil-in-water nanoemulsions fabricated utilizing high energy approach, i.e. high pressure homogenisation method was found to reduce dispersed phase particles size in the range of 150–160 nm. Minimal non-significant variation in droplet size and surface charge over the 8 weeks storage periods proves their excellent shelf-life stability. The use of MPI as surfactant for the delivery system also increased the lipid fraction digestibility releasing 70% of the fatty acids from dispersed phase oil droplets in simulated intestinal phase of three step in vitro digestion of nanoemulsion as compared to its conventional counterpart. The γ-oryzanol rich nanoemulsions improved prophylactic effectiveness against ROS in terms of overall cell survival and cell membrane integrity. The results will pave new domains to use MPI as surface active agents for delivery system formulation enriched with nutraceuticals and phytochemicals possessing superior functional advantages, bioavailability and antioxidative potentials.

DEM-simulation of thin elastic membranes interacting with a granulate

For a wide range of applications, we need DEM simulations of granular matter in contact with elastic flexible boundaries. We present a novel method to describe the interaction between granular particles and a flexible elastic membrane. Here, the standard mass-spring model approach is supplemented by surface patches given by triangulation of the membrane. In contrast to standard mass-spring models, our simulation method allows for an efficient simulation even for large particle size dispersion. The novel method allows coarsening of the mass-spring system leading to a substantial increase in computation efficiency. The simulation method is demonstrated and benchmarked for a triaxial test.

Monodispersed calcium oxalate as highly effective support filler in PMMA-based nanocomposite

This study focuses on the synthesis of monodispersed CaC2O4 particles of cubic and donut-shaped novel morphologies and the ultrasonic-assisted in-situ polymerization of PMMA/CaC2O4 in the presence of native CaC2O4 and commercial CaC2O4 particles (0.2–0.8 wt%). The current study explored that particle loading played its role in defining the optimal conditions, whereas the particle morphology, uniformity, concentration, and reaction parameters of the fillers greatly influenced the properties of the resin-based nanocomposites. These observations confirmed that the calcium oxalate filler nanoparticles had an obvious effect on the tribological and mechanical properties of the as-fabricated composite. The optimum concentrations of fillers for enhanced properties of the composite were 0.4, 0.6, and 0.8 wt%, respectively for donut-shaped, cubic-shaped, and commercial calcium oxalate. The incorporation of donut-shaped particles showed enhanced properties as compared to nanocomposites consisting of commercial and cubic-shaped CaC2O4 particles. Enhancements in the properties of nanocomposites for different loadings of donut-shaped CaC2O4 as compared to blank PMMA are anti-wear = 51.02 ± 0.15%, COF = 66.60 ± 0.4%, and microhardness = 10.50x ± 0.06. These improved properties compared to the previous literature are essentially attributed to the particle morphology, size, uniformity, and uniform dispersion of CaC2O4 in the polymer matrix due to intense micro-convection generated by sonication.

The seasonal movement of sediment-associated marine-derived nutrients in a morphologically diverse riverbed: the influence of salmon in an Interior British Columbia river

PurposeThis study (1) investigated the extent to which flocculation and the hydrological and morphological attributes of an interior salmon-bearing river regulate the seasonal storage of marine-derived nutrients (MDN) and (2) compared the contribution of MDN to the fine bed sediment relative to other nutrient sources to the river.MethodsPrevious research has determined that the co-existence of re-suspended fine sediment, generated by salmon redd construction, with salmonid excretion and decay products in the water column creates ideal conditions for the flocculation of these inorganic and organic particles. Stored and suspended fine bed sediment was sampled from seven sites with varying morphologies and bed substrate down the length of a large spawning river in the interior of British Columbia over a 12-month period. MDN contributions to the sediment was tracked using aggregated versus dispersed particle size, carbon-to-nitrogen ratios, stable carbon and nitrogen isotopes, and MixSIAR modeling.Results and discussion(1) There was a significant longitudinal spatial distinction of nutrient retention between sites upstream and downstream of a large seasonally inundated floodplain; (2) the MDN isotopic signal in the surficial stored bed sediment in this sample year was short term; and (3) upstream spawner numbers, substrate size, stream morphology, and discharge were relevant to both the magnitude and retention time of sediment-associated MDN.ConclusionA cumulative magnification of MDN was correlated with the distance from the headwaters and the number of upstream spawners. The relationship between MDN retention in interior rivers, and possible multi-year accumulation, was influenced by variability in channel morphology, substrate size, and the presence of an inundated floodplain halfway down the river.

CFD-PBE Simulation of Flow Dynamics and Mass Transfer in Two-Stage Countercurrent Mixer-Settler

Flow condition and mass transfer behavior of liquid–liquid extraction in a two-stage countercurrent extractor are investigated experimentally and numerically. CFD-PBE simulation is adopted to analyze the impact of operating parameters, including impeller speed, residence time, and organic-aqueous ratio of feed flow on volume fraction and droplet size of dispersed phase and volumetric mass transfer coefficient. Droplet size distribution is calculated by considering breakage and coalescence of dispersed phase. The allocation of dispersed phase between stages is found to be determined by impeller speed. Meanwhile, the allocation of dispersed phase between mixers and settlers is governed by residence time and organic-aqueous ratio of feed flow. Turbulence intensity, volume fraction, and droplet size distribution are revealed to be dominating parameters that affect the spatial nonuniform distribution of volumetric mass transfer coefficient. The mass transfer rate can be improved by increasing impeller speed in two stages. Higher residence time and organic-aqueous ratio of feed flow, however, have opposite effects on mass transfer rate in stage-1 and stage-2.

Gold Nanoparticles Mineralized by Peptide Liquid Crystals with Dual-Functional Enzyme-like Activities: An Automatic Membrane Reactor for Glucose Detection.

The development of stable multifunctional enzyme mimics with tandem catalytic effects provides a great opportunity to construct economical and convenient bioassays. Inspired by biomineralization, in this work self-assembled N-(9-fluorenylmethoxycarbonyl)-protected tripeptide (Fmoc-FWK-NH2) liquid crystals were used as templates to in situ mineralize Au nanoparticles (AuNPs), and then a dual-functional enzyme-mimicking membrane reactor based on AuNPs and peptide-based hybrids was constructed. AuNPs with a uniform particle size and good dispersion were in situ reduced on the surface of the peptide liquid crystal due to the reduction of the indole group on the tryptophan residue, which exhibited excellent peroxidase-like and glucose oxidase-like activities simultaneously. Meanwhile, the oriented nanofibers aggregated into a three-dimensional network, which was further immobilized on the mixed cellulose membrane to form a membrane reactor. A biosensor was made to realize fast, low-cost, and automatic detection for glucose. This work represents a promising platform for the design and construction of novel multifunctional materials based on the biomineralization strategy.

Preparation, characterization and properties of cinnamon essential oil nano-emulsion formed by different emulsifiers

Essential oil has unstable properties and low bioavailability. In order to improve these problems, with the help of ultrasonic wave, stable nano-emulsions were prepared with different emulsifiers. In this experiment, the formation of nano-emulsions with different emulsifiers at different concentrations was studied, including sodium caseinate (SC), whey glycoprotein (WGP), soy protein isolate (SPI) and Tween 80. Meanwhile, we studied the effect of ultrasonic cell disruption apparatus and homogenizer on the particle size of nano-emulsions. Cinnamon essential oil nano-emulsion prepared under the optimum emulsifier and its concentration has good microstructure and rheological properties. The stability of cinnamon essential oil nano-emulsion in different environments was studied, including centrifugation, freeze-thaw, heating-freezing and long-term (30 d) stability. The nano-emulsion of cinnamon essential oil is stable in emulsifiers. The nano-emulsions prepared by different emulsifiers has different particle sizes in different environments and their advantages and disadvantages are compared. Finally, how different nano-emulsion were digested in vitro was also studied. The in vitro digestion of nano-emulsion by different emulsifiers was simulated. Its properties include particle size, zeta potential and polymer dispersion index (PDI).

Formation of the structure of low-calorieice cream with vegetableing redients

The quality of ice cream depends on many factors: raw materials, recipe, production and storage conditions, etc. The choice of ingredients during the manufacture of ice cream is an important factor that not only affects the nutritional value and functional orientation, but also the formation of the structure of the final product. Low-calorie ice cream, in terms of its composition and characteristics, best meets the requirements for healthy food products. However, in low-calorie ice cream, the mass fraction of moisture is too high (about 70 %), as a result of which noticeable ice crystals form in it during freezing. Therefore, in order to improve the organoleptic and rheological indicators of low-calorie ice cream, it is necessary to increase the mass fraction of dry substances by using milk processing products, namely, skimmed milk powder (SMP) and whey concentrates (whey protein concentrate (WPC), dry demineralized whey (DWW), vegetable (apple powder) ingredients, including grain (rice and sesame flour), dietary fibers (inulin, etc.). The purpose of the work was to study the influence of whey concentrates and plant ingredients on the formation of the structure of low-calorie milk ice cream during its production. The article presents the results of research on the dispersion of structural elements of low-calorie ice cream mixtures and structural-mechanical properties based on indicators of effective viscosity and activation energy. It was established that with an increase in the shear rate, there is a decrease in the effective viscosity indicators in all samples of milk mixtures for ice cream. The presence of whey and vegetable components in ice cream mixes helps to increase the consistency coefficient and activation energy. Moreover, in the milk mixture with WPC and rice flour, these indicators are 2.8 times higher than the indicators of the control, which is represented by a traditional type of milk ice cream. As a result of the study of the microstructure of the low-calorie mixture samples, it was established that after processing, the low-calorie ice cream test samples are more saturated with air, and, therefore, their whippedness is higher compared to the control. It is shown that the air bubbles in the experimental samples are homogeneous and evenly distributed over the entire surface of the ice cream. At the same time, the content of finely dispersed air bubbles in experimental ice cream samples with sizes from 1 to 30 microns is in the range of 29-43 %, in contrast to the control, in which it is 18 %. It has been experimentally proven that the addition of whey concentrates and vegetable ingredients to the ice cream mixture followed by processing contributes to the formation of a homogeneous structural frame with an even distribution of components in the finished product. The obtained research results confirm the significant influence of the viscosity of the mixtures on the whipping of ice cream and the size of dispersed air particles. Key words: low-calorie ice cream, mixture for low-calorie ice cream, whey concentrates, vegetableingredients, rheological indicators, microstructure.

TiO2 Coating on SiO2 Nanosphere Supported Pd Catalyst for the H2–SCR of NOx in the Presence of Oxygen

A highly active Pd supported on TiO2 coating on a SiO2 nanosphere (Pd/SiO2–TiO2(C)) catalyst has been developed for the selective catalytic reduction of NOx by H2 (H2–SCR). The coating structure of TiO2 on the SiO2 nanosphere exerts an important effect on the catalytic performance of the catalyst. This Pd/SiO2–TiO2(C) catalyst shows superior activity with 93.2% NOx conversion at 150 °C, and high tolerance to CO and H2O, which is significantly outperformed Pd supported on TiO2 particle (Pd/TiO2) catalyst. Compared with Pd/TiO2, Pd/SiO2–TiO2(C) has higher Pd dispersion and smaller Pd particle size, more surface chemisorbed oxygen, and metallic Pd species, all of which contributed to the improved performance. In situ diffuse reflectance infrared Fourier transform spectroscopy (in situ DRIFTS) reveals that more reactive NOx, NH3, and NH4+ species formed on Pd/SiO2–TiO2(C), and the CO poisoning is mainly due to the slight inhibition of the formation of these reactive species. This research provides a promising strategy to design a superior H2–SCR catalyst for the removal of NOx.

Synergistic Effect of Activated Carbon, NiO and Al2O3 on Improving the Thermal Stability and Flame Retardancy of Polypropylene Composites.

It is difficult to enhance the char yields of polypropylene (PP) due to the preferential complete combustion. Successful formation of abundant char layer structure of PP upon flammability was obtained due to the synergistic effect of NiO, Al2O3 and activated carbon (AC). From characterization of scanning electron microscopy (SEM) and transmission electron microscopy (TEM), it was revealed that the microstructure of residual char contained large amount of carbon nanotubes. Compared to the modification of AC, NiO and Al2O3 alone, the combination of AC, NiO and Al2O3 dramatically promotes the charring ability of PP. In the case of AC and NiO, NiO plays a role of dehydrogenation, resulting in the degradation product, while AC mainly acts as carbonization promoter. The addition of Al2O3 results in higher dispersion and smaller particle size of NiO, leading to greater exposure of active sites of NiO and higher dehydrogenation and carbonization activity. Compared to the neat PP, the decomposition temperature of the PP modified by combined AC, NiO and Al2O3 was increased by 90 ℃. The yield of residual char of AC-5Ni-Al-PP reached as high as 44.6%. From the cone calorimeter test, the heat release rate per unit area (HRR) and total heat release per unit area (THR) of PP composite follows the order AC-5Ni-Al-PP < AC-10Ni-Al-PP < AC-Ni-PP < AC-15Ni-Al-PP < AC-1Ni-Al-PP. Compared to the neat PP, the peak of HRR declined by 73.8%, 72.7%, 71.3%, 67.6% and 62.5%, respectively.

In situ self-assembly preparation and characterization of CaO–ZrO2 nanopowders under vacuum

CaO–ZrO2 nanocomposite powders were prepared by in situ self-assembly method under vacuum. The effects of calcium oxide content on the physical phase composition and microscopic morphology of the as-prepared nanopowders were investigated. The results showed that the content of the tetragonal phase in the powders gradually increased with increasing calcium oxide content. When the calcium oxide content reached 10 wt%, the prepared CaO–ZrO2 nanopowders were a pure tetragonal phase with good dispersion and average particle size about 57 nm. In comparison to the situation in air, the amorphous carbon particles formed by the pyrolysis of organic matter under vacuum were evenly distributed on the surface of the nanocomposite particles or between them. In this way, direct contact of the nanoparticles was avoided, thus inhibiting their rapid growth at high temperatures and facilitating the formation of fine grains with high surface energy. The preliminary results indicated that the smaller average particle size and narrower particle size distribution of the nanocomposite powders prepared in vacuum were significantly beneficial for improving the bending strength of the nanoceramic products compared to that in air. It is expected to provide valuable information for further optimization of the controllable preparation of high-quality nanoceramic powders.

Chitosan‐coated nanoliposomes for the enhanced stability of walnut angiotensin‐converting enzyme (ACE) inhibitory peptide

This study encapsulated walnut angiotensin-converting enzyme (ACE) inhibitory peptides within nanoliposomes and then modified them with chitosan. The resulting effect of the nanoliposome loading and chitosan coating on physicochemical characteristics, stability, bioactivity, chemical structure, and morphology of the encapsulated peptides was assessed. The resulting particle size and polymer dispersity index revealed that the chitosan-coated nanoliposomes loaded with walnut ACE inhibitory peptides (WAIP) (CL-P) exhibited higher physical stability compared with the nanoliposomes loaded with WAIP (L-P). The encapsulation efficiency (EE) of CL-P increased from 73.32% to 76.13% after chitosan modification, and the EE of L-P and CL-P could be maintained by storage at 4°C. In addition, the antioxidant activity and ACE inhibitory activity of the peptides were effectively protected by L-P and CL-P during storage. Fourier transform infrared spectroscopy showed that the nanoliposomes were bound in ionic form with both the peptides and chitosan. Transmission electron micrographs indicated the presence of vesicle-like carriers with a reservoir-type structure. This study highlights the potential of nanoliposomes and their modification with chitosan to increase the stability and bioactivity retention of ACE inhibitory peptides. PRACTICAL APPLICATION: Chitosan-coated nanoliposomes loaded with walnut ACE inhibitory peptides were prepared in this study. Chitosan coating increased nanoliposomes' encapsulation efficiency and provided higher physical stability. In addition, the bioactivity of the walnut ACE peptides was effectively protected during storage. This study was relevant for improving the storage and transportation used for nanoliposome systems applied in the food and health product industry.

Understanding the evolution of particle size dispersion with time in a fluidised bed granulation process

Minimisation of final size dispersion remains an important objective of fluidised bed granulation. Some of the factors that control the evolution of the granule size distribution with time in such a process are examined using a validated aggregation model. The aim is to understand the intrinsic behaviour of size dispersion versus time with an approach that is not specific to a particular system of fluidised granulation. Because relative size dispersion (size dispersion compared to the mean size) is also important, the study also examines the evolution of mean granule size versus time. The model includes an aggregation rate that is time and size dependent and a granule kinetic energy dissipation mechanism. The relative importance of these components of the model is quantified in terms of how they control the output and it is shown that the action of the energy absorption mechanism (implemented using the viscous Stokes criterion) makes the dominant contribution although the interplay with the other effects is also significant. Mean granule volume monotonically approaches a quasi-stable asymptotic value while standard deviation in granule volume passes through a peak value before falling to a lower, quasi-stable asymptotic value. The reasons underlying such behaviour are outlined. Two new temporal parameters, an equivalent aggregation time constant and a Stokes time constant, are developed and can be employed to predict and interpret system behaviour. Such knowledge can then be applied to suggest how dispersion in size can be controlled within certain intrinsic limits, which will be of interest to the industry.

THE STUDY OF HETEROGENEOUS SYSTEMS AND METHODS FOR THEIR SEPARATION

The article shows the importance of methods for separating inhomogeneous systems, classified depending on the size of dispersed particles, the difference in densities of continuous and dispersed phases, as well as the viscosity of the continuous phase. The main methods of separation are considered: sedimentation, filtration, centrifugation, wet separation.

Modeling the Breakdown of Dielectrics Loaded With Conducting Particles

This study addresses the electrical breakdown of dielectrics loaded with randomly dispersed conducting particles. A simple stochastic breakdown model is proposed and used to provide information on the tree structure and dielectric breakdown strength. Parametric simulations suggest an important role of the particle fraction and microstructure (regular versus aggregated) on the breakdown strength while the particle size and size dispersity have limited effects. The obtained results have been recast in terms of geometrical parameters describing the particle structure and the minimum-gap path (path having the shortest length of dielectrics) is found to correlate quite well with numerical results. This suggests that simple geometrical quantities are relevant to provide quantitative predictions of breakdown strength for such materials.

Combinatorial approach to fabricate silica doped polyvinyl alcohol/hydroxyapatite/carrageenan nanocomposite for bone regeneration applications

AbstractBone tissue engineering is a dominating approach for the fabrication of nanocomposite bone implants with superior biocompatibility and low toxicity to the surrounding tissues. Here, in this report ternary nanocomposites integrating nanohydroxyapatite/κ‐carrageenan/silica doped polyvinyl alcohol in three different ratios, that is, 60/30/10 (HCP1), 60/20/20 (HCP2), and 60/10/30 (HCP3) was constructed and a binary system comprised of nanohydroxyapatite and κ‐carrageenan was also prepared for analyzing and comparing their bone regeneration potential. The samples were characterized by various physico‐chemical techniques such as infra‐red spectroscopy, which furnished details about structural functionalities and complex formation. Rough surface morphology and dispersed particle size distribution of developed nanocomposites were revealed by scanning electron microscopy and electron transmission microscopy, respectively. Thermogravimetric analysis and differential temperature analysis revealed higher thermal stability of HCP3 nanocomposite with total weight loss of 10% and X‐ray diffraction analysis revealed average crystallite size of 15 nm for HCP3 nanocomposite. Bioactivity and biocompatibility of fabricated nanocomposites were deduced with the help of biological techniques. HCP3 manifested cell viability above 100% at 2 μg/mL concentration and exhibited hemolysis below 3% at all tested concentration favoring cell growth with minimum cytotoxicity. HCP3 also exhibited efficient apatite layer deposition, optimum swelling ability and improved biodegradability (~30%) and anti‐bacterial activity predicting it as a promising nanocomposite implant for future orthopedic applications.

An experimental study of the sooting behavior of a partially premixed flame under moderately rich conditions

Soot and its gaseous precursors are quantified in detail (precursors up to 166 amu, volume fraction, particle size, number concentration, and light emissivity dispersion exponent) in a laminar partially premixed counterflow flame of ethylene. The investigated flame has an equivalence ratio Φ = 2.43 and a mixture fraction Zst = 0.4, resulting in a distinct double-flame structure consisting of a rich premixed flame component and a diffusion flame component, both stabilized on the fuel side of the stagnation plane. The value of the equivalence ratio makes the premixed flame the dominant contributor to soot production, with soot being oxidized completely by OH from the diffusion flame component. Particle size is measured to increase quasi-monotonically, but remains within a few nanometers throughout the soot forming region. Aromatic species are primarily formed in the post flame region of the premixed flame. Their mole fractions peak close to the premixed flame and decrease as the diffusion flame is approached. The experimentally measured gaseous species are captured well by kinetic models, with the exception of two critical species in soot chemistry: benzene and naphthalene.