Purification of Inkjet Ink from Water Using Liquid Phase Electric Discharge Polymerization and Cellulosic Membrane Filtration

Mechanistic Insight of Pseudo-lignin Formation and Its Impact on Enzymatic Hydrolysis

A method to separate inkjet ink form water was developed using liquid phase electric discharge free radical polymerization, then filtration of ink using a 0.8 micron filter cellulose acetate membrane. The electric discharge polymerization process generates free radicals by stripping off hydrogen atoms from ink molecules. Once the radicals are generated polymerization takes place and creates very large molecular weight molecules that can be easily separated from water. The mechanism was verified as free radical using small molecule analysis of methanol that had undergone the electric discharge process. Since 1,2-ethanediol was found in the solution after the discharge process, positive confirmation could be made that the process was free radical. This technique was very effective in removing ink from water changing variables such as: discharge time; ink concentration; volume of mixture; power of discharge and pH.

Direct Measurement of Cellulose Degradation by C. Thermocellumin the Surface of Microcrystalline Cellulose using MALDI-MS

Biomass is one of the most abundant potential sustainable sources for fuel and material production, however to fully realize this potential an improved understanding of lignocellulosic recalcitrance must be developed.  In an effort to appreciate the underlying phenotypic, biochemical and morphological properties associated with the reduced recalcitrance observed in tension stress-induced reaction wood, we report the increased enzymatic sugar yield and corresponding chemical and ultrastructural properties of Populus tension wood (TW).  A series of complimentary analytical techniques were used to describe changes occurring as a result of the formation of a gelatinous cell wall layer.  Along with bulk analysis by gel permeation chromatography (GPC) and 13C solid-state nuclear magnetic resonance (NMR), surface characterization with chemical image can provide  spatial and lateral information.

Herein, we illustrate the application of chemical imaging technique to understand biomass recalcitrance; time-of-flight secondary ion mass spectrometry ﴾ToF-SIMS﴿ and Coherent anti-Stokes Raman scattering (CARS) Microscopy.  ToF-SIMS has been applied to achieve the major component images (e.g. cellulose, xylan, and lignins) and their semi-quantitative variation on the surface of poplar stem. The ToF-SIMS images represent excellent cell wall components under submicron scale.  3D microanalysis combined with surface sputtering also shows lateral distribution of major components of tension wood which can be related to the recalcitrance of biomass. CARS Microscopy has been developed and applied for biomass imaging, and this unique tool is powerful in imaging complex biological systems in-situ, specifically in identifying recalcitrant features evolving in biomass with reference to their processing to biofuels.

Effect of Steam Explosion on Degradability and Accessiblity of Loblolly Pine in Bioethanol Applications

Biomass is one of the most abundant potential
energy resources for fuel nowadays. It is renewable
and sustainable thus thought to be an excellent
replacement for fossil fuels.

Comparing to grain and sugar based first generation
biofuel, non-food lignocellulosic based second
generation ethanol is more preferred due to the
elimination of competition for food and environmental
friendliness.

Lignocellulosic materials are known to be extremely
recalcitrant to enzymatic hydrolysis due to the tightlypacked and highly-ordered 3D structure.

Loblolly pine, one of the most recalcitrant softwood
species, was subjected to SO₂ aided steam explosion and the resulting steam exploded loblolly pine (SELP) was used for a series of investigation.

Non-wood Pulping and Papermaking

We investigate the possibility to substitute a fraction of agricultural residue for woodchips. The research focuses on chemical and mechanical pulping of blends of agricultural residue and virgin wood. The capabilities and the primary results of the research allow to evaluate the impact of co-pulping on physical and optical properties of handsheets.

Hysteresis Enabled Biomedical Testing on Superhydrophobic Paper

Fabrication of surfaces with heterogeneous contact angle hysteresis enables extraction of droplet samples from bulk liquid volumes. These surfaces are created by printing high hysteresis wax islands onto low hysteresis superhydrophobic paper. The volume of the sampled droplets depends on the hysteresis of the printed islands, which can be controlled through both physical and chemical means. Physically, hysteresis is modified through the addition of surface roughness. Chemical hysteresis is tuned by changing the active chemical groups present on the wax surface. The observed control of the volume of sampled droplets, which is necessary for quantitative biochemical or chemical assays, extends to scenarios in which multiple droplet samples are extracted simultaneously from a single bulk droplet. The ability to obtain well-defined microliter sample volumes and to extract several samples simultaneously from the same source enables the development of 2D paper based microfluidic devices for biomedical testing.

Hydrodeoxygenation of Lignin Pyrolysis Oil via Thermal Catalytic Reaction in Aqueous Phase

Lignin has a very complex structure. It has three basic monomers with over 20 kind of linkage. The complex structure makes it very hard to decompose to small pieces. Pyrolysis is one of the most economic ways to break down the lignin. The disadvantage is that the pyrolysis oil derived from this process has very high oxygen content and unsaturated bond. Therefore, the upgrading of pyrolysis oil is necessary.

The pyrolysis oil has two phases, the heavy oil phase (water-insoluble) and light oil phase (water soluble). In my study, a two-step method to hydrodeoxygenate the heavy oil in aqueous phase is used. After the treatment, no aromatic ring and other unsaturated bond were left. The oil was broken down to monomers with transparent apparent. The C13 NMR study indicated the removal of oxygen occurred in the process. The yield for this process was 33%. The light oil derived from wood achieved 100% yield and fully hydrogenated. The light oil from residual could only be partially hydrogenated but the yield is also 100%. The bark could be fully hydrogenated but the yield is 80%. The reaction mechanisms for all the processes above are discussed.

Role of Pyrolysis Conditions in the Evolution of Biomass Char Morphology and Gaseous Products

A major advantage of biomass gasification is that waste and residue from forest and paper industry can be converted to syngas. Biomass gasification involves pyrolysis and char gasification steps in series. Pyrolysis experiments on pine and switchgrass (particles of 180-250µm) were performed in Laminar Entrained Flow Reactor (LEFR) and Pressurized Entrained Flow Reactor (PEFR). Measurements in LEFR were made at a residence time of 4 s and at 600-1000°C and PEFR at 5, 10 and 15 bars and 600-1000°C and at a residence time of 10 s. Scanning Electron Microscopy (SEM) was used to study the effects of pyrolysis temperature and pressure on char morphology. The results show that with increase in pyrolysis temperature particles gained more sphericity. The pyrolysis gaseous products tend to trap in the char particles at higher pressures creating distinct gas pockets. Melting and reconstitution was observed at higher pressure which indicated the presence of an internal skeletal structure. Char morphology and structure is strongly impacted by the increased pressure during devolatilization and is likely to affect char gasification activity.

Cellulosic Nanocompositeas a Potential Scaffold in Cardiovascular Tissue Engineering Designing

Cellulose nanowhiskers (CNWs) with its renewable and environmentally benign nature, and its abundance and excellent biocompatibility could potentially open a new avenue in cardiovascular tissue engineering for small caliber grafts. Inspired by this bioapplication, we have designed a fully bio-based nanocomposite of aligned CNWs embedded in a matrix of cellulose acetate possessing a controlled biodegradability, 3D porosity, and non-acidic byproducts as opposed to degradable PLA/PGA. To ensure uniform distribution, CNW were delicately extracted from a multi-stage process and dispersed in a solvent of choice prior to mixing with the matrix to inhibit whiskers flocculation. Comparable to Carbon Nanotubes or Kevlar, CNWs imparts significant strength and directional rigidity to the composite even at 0.2 wt% yet doubles that within a controlled magnetic field of only 0.3T. We believe our fibrous porous aligned nanocomposite could expand the biomedical applications of cellulose-based materials while provide a potential scaffold in vascular tissue engineering.

Hydrodeoxygenation of Lignin Model Compounds via Thermal Catalytic Reactions

The production of renewable specialty chemicals and fuel additives is of major importance as the economies of the world continue to grow while fossil resource production declines. At present, roughly one third of biomass entering paper mills is used a low grade boiler fuel. The majority of this fuel is lignin which is a branched phenolic polymer with base molecular weight near that of gasoline. In this work, I will attempt to hydrodeoxygenate lignin model compounds with Pt/C catalysts in organic and aqueous solvents under hydrogen atmosphere to compare solvent hydrogen solubility effects. In later work, depolymerization of lignin will be assessed to determine operating parameters necessary for the development of a biorefinery.

Structural Characterization of Lignin in Agave Americana

As part of our efforts to investigating the biomass recalcitrance in Agave, we studied the plant cell wall structure by whole cell NMR analysis in perdeuterated pyridinium chloride –DMSO d₆ and since the lignin content in Agave is significantly low in order to get a detailed information about various lignin sub-units, we isolated enzymatic lignin from Agave americana leaf (AAL) and heart (AAH) bagasse and it is characterized by ¹³C NMR, ¹³C-¹H HSQC NMR and Gel-permeable Chromatography. Agave Americana lignin characterized as syringyl rich with an S/G ratio as 1.75 and 1.20 for AAL and AAH respectively. The lignin side-chain units identified are β-aryl ether, phenyl coumaran, resinol and spirodienone. Based on a semi-quantitative estimation of the side-chain units from the ¹³C-¹H HSQC spectra the amounts of resinol and phenyl coumaran are significantly high in Agave Americana Heart (AAH).

Packaging materials are used for food stuff, pharmaceuticals, cosmetics and other dry goods.  Packaging materials provide a barrier against air, water, grease, microbes and odor. Packaging materials currently in use consists of glass, metals (aluminum and tin), petroleum based plastics and paper coated with aluminum, wax and plastic. These materials have various disadvantages; they are unsustainable (metals), fragile (glass), increase cost of transportation (glass) and not are renewable (metals, coated papers). The packaging industry is values at around $4 Billion currently and is projected to grow at 3% a year. Therefore there is a need to replace conventionally used, unsustainable packaging materials with completely renewable, recyclable, biodegradable packaging materials which can provide the same properties as conventionally used packaging materials.

Pure cellulose based packaging material are unheard of since they do not have good barrier properties in the native form. At IPST there have been recent developments in the field of Nanocellulosic barrier materials. Nanocellulosic materials are composed of cellulose fibers of diameter 10-50nm and lengths up to 1000nm. These materials can be easily modified chemically and can be cast into dense coatings.   Materials that offer excellent gas barrier properties while being completely renewable, biodegradable, nontoxic and stable have been developed. Additionally, they are lightweight and can help reducing transportation costs and are easily stored.

Obtaining a better understanding of the complex mechanisms occurring during lignocellulosic breakdown is critical to the growth of renewable and clean biofuel production. A key step in bioethanol production is pretreatment to reduce cell wall recalcitrance for downstream processes. We have shown in an earlier study this pretreatment can cause a decrease in cellulose degree of polymerization, increase in cellulose crystallinity and accompanying increase in the cellulose microfibril dimensions during dilute acid pretreatment, which is similar to the of synthetic polymers. This process could have large implications with respect to enzymatic deconstruction efforts, therefore in an effort to understand this phenomena poplar with controlled lignin contents are pretreated with dilute sulfuric acid (0.1 M) at 160 ℃ for 15 min and 35 min. Solid-state CP/MAS 13C NMR, GPC, HPLC and FTIR were applied to investigate how cellulose crystallinity, and degree of polymerization along with other chemical signatures of degradation change during pretreatment as a function of lignin content.

Flexible Electronic Papers Fabricated from Microfibrillated Cellulose

Cellulose, as the main component of the paper, is a polysaccharide consisting of thousands of β -linked glucose unit. Cellulose not only is the most abundant biopolymer in the world but also has excellent mechanical properties. Using paper-based substrate for electronic devices has become a new research focus, because paper has the advantages of being environmental-friendly, transparent and flexible. In my work, first, a paper-based ionic diode consisting two oppositely charged cellulose nanofibrils sublayers was studied. Paper based solar cell is another electronic devised that will be studied.