Membrane Processes and Surface Chemistry Modification

Joseph Imbrogno-Department of Chemical and Biological Engineering-CBIS

Talked to us about the different characteristics of membranes, and how those characteristics affect the purpose and function of the membrane.  The Achilles heel of membranes is excessive fouling-Joe was trying to prevent and/or find ways to correct the fouling of a membrane.   Later, we went into the lab and found that it is fairly easy to make a membrane, with basic chemistry of polymers, solvents and non-solvents (phase inversion).

Uses:

Desalination—removing salt (and other minerals) from water

Food Production—purifies and concentrates food components; ultrafiltration of milk yields cheese

Reverse osmosis—treats and purifies drinking water

Types:

Symmetric vs. Asymmetric—pores are all the same size for symmetric membranes and pores are varying sizes for asymmetric membranes

Organic vs. Inorganic—depends on the material:

Organic—natural polymers, Teflon PTFE (polytetrafluoroethylene), rubber, wool, cellulose and polyamide-imide (PAI)

                Inorganic—metallic powders, and ceramics

Hydrophilic vs. Hydrophobic—for protein separations, hydrophilic surfaces perform the best

Fouling—irreversible build-up of solute at or in the membrane and will eventually lead to stop of flow completely

Occurs 3 ways:

Pore blockages-particles block the pores of the membrane

Pore constriction—particles “stick” to the inner walls of the pores of the membrane and cause a decrease in flow of the solution

Cake formation—solute lays down and forms thick layers on top of membrane and complete blocks pores and membrane surface

Two Types of Flow:

Cross Flow—solution flows tangential to the membrane and only the particles that can fit through pores are able to pass through membrane—much more effective

Dead-End Flow—solution flows head on into the membrane—results in more fouling

Ternary Diagram:

Don't worry too much about this for the quiz: A graph/diagram with 3 variables and axis’s: membrane type, pore size and type, and casting composition.  Phase 1 is the solvent and polymer before the membrane is produced, Phase 2 is the result of the three variables and how they will affect each other.  The variables will add up to a constant, K, usually 1.0 or 100%.  The graph shows the ideal efficiency and one could find the actual efficiency, using the actual values of each variable.       

Connections:

Dr. Koratkar—dropped material in water (non-solvent) and an entirely different outcome was produced

Dr. Ullal and Palermo—characteristics and properties of materials determine the results yielded by that material

Protein interactions

Name : Brian Murray
Department : Chemical and Biological Engineering
Topic : Protein-Protein Interactions
Date : November 24,2015

Social Value

 The research we learned about is important because it affects many of our lives. Understanding
how proteins interact with each other is extremely important in understanding protein based
diseases such as Alzheimer’s, Parkinson’s, Huntington’s, and many more. The better we
understand such diseases, the closer we get to being able to combat and defeat them.


Government Connection

The fingerprint experiment connects to government because when a crime takes place, police
often use forensics to detect fingerprints at the scene. Fibril detection is similar to fingerprint
detection because it breaks down to the organic chemistry of each thing.

Economics Connection
●
If the detection is used in health care, it will have to be done at a cost that is available to
patients. This relates to “Economies of Scale.”

● Resistance cost
Antibiotics
are becoming less effective and it’s costing the US $2134
billion a year to fix it. If we can develop the solution, it can save billions in the budget (and many lives)

Guest Connections
●Ullal and Palermo proteins
are also polymers
● Lindhardt Relating
to health care
● Silva Polymers
● Borten Economies
of Scale

Terms/Concepts
●Protein Linear
chain of amino acids
● Neurofibrillary Tangles The
reason why some diseases occur
● Amyloid Plaques - build up of tangles; obvious in autopsy of diseasesd.
● ABeta
The
protein responsible for Alzheimer’s Disease
● Amyloid Fibers
When
the ABetas
stick together
● Antimicrobial Resistance
Bacteria
start becoming tolerant to medicines
● Antimicrobial Peptides
one possible olution
to eliminating Antimicrobial Resistance

Tour

Tuesday November 24, 2015

Presenter: Dr. Marimar Lopez

Department: Director, CBIS Research Core Administration

Topic:Tour of the Building

There are several state-of-the-art Research Cores at the Center for Biotechnology and Interdisciplinary Studies Building.  These resources are available to Rensselaer faculty, staff and students.

•     Nuclear Magnetic Resonance (NMR)- Best technique for determining structure of organic compound. (For example, does the substance have a ring of carbons, or a straight chain? Does it have a carbon bonded to an oxygen bonded to a different carbon, or does it have a carbon double bonded to an oxygen?) Also, NMR can be used to determine if a substance is pure (hmmm...this substance isn't supposed to have any R-C-OH bonds, something else must be in here.)  It is a physical phenomenon in which nuclei in a magnetic field absorb and re-emit electromagnetic radiation.  It is used  for “solution structure determination” (determine structure of an organic compound) of tiny molecules such as proteins, carbohydrates, and macromolecular complexes at atomic resolution. 

•     Isothermal Titration Calorimeter- Used most often to study how small molecules (such as pharmaceuticals) bind to large molecules (such as proteins.) Allows simultaneous determination of binding parameters such as the equilibrium constant, enthalpy of binding and stoichiometry of the interaction

•     Chromatography-  This is not your elementary school "smash up leaves and let them streak into colors" stuff. These are elaborate techniques to separate a mixture by a specific characteristic of its components. The entire mixture is passed through a medium that proportionally slows down molecules based on a certain parameter.   Laboratory techniques for the separation of a mixture. If I ran a chemical experiment and wanted to quantify and identify every component in the resulting solution, I would use chromatography (likely HPLC - high pressure liquid chromatography).

•     X-Ray Crystallography- Equipment used to identify the atomic and molecular structure of a crystal.  Crystalline atoms cause x-rays to diffract into many specific directions. This would be used to determine the structure of atoms in a substance. Dr. Shi talked about this as well, when he talked about atoms functioning like slits for diffraction - visible light waves have a wavelength of about 5000 atoms, so we cannot tell one atom from another if we shine visible light on them. But xrays have much tinier wavelengths and seeing how atoms diffracts xray waves tells us how atoms are connected - at what angles, in what crystal pattern, etc.

•     Atomic Force Microscopy- This can be used to slowly scan the surface of small material, down to resolution of tens of nanometer.  It is very gentle and can be used to monitor real time transcription (copying DNA), and real time interaction between sub-cellular biological molecules such as microtubules and proteins. It can resolve structures on nanometer scale.  It has a dry and wet mode scanning.  A bioheater module facilitates live cell imaging for cells where temperature control is essential.

•     Klett Meter- Used to measure cell growth

•     Centrifuge- It is an equipment with a rapidly rotating container that applies centrifugal force to its contents.  It is used to separate fluids of different densities(or liquids from solids). 

•     Mass Spectrometer- Instrument which can measure the masses and relative concentrations of atoms and molecules.  It uses the basic magnetic force on a moving charged particle.  Basically you smash up something into its component ions, measure the abundance of those ions, and then back-calculate what that substance was . If you want to know "what is this?" the mass spec is your first instrument to try.

•     Microbiology and  Fermentation(Smelly Room)- Facilitates bacterial growth, harvesting and processing on a small, medium. and large scale

•     Sonicator- Sound/ Ultrasound is used to disrupt cell membrane and release cellular content. (Dr. Koratkar also used an ultrasonicator.)

Sources

http://biotech.rpi.edu/facilities

http://biotech.rpi.edu/facilities/nuclear-magnetic-resonance-research-nmr

Metals and Ceramics

Quick summary from today:

• What's a question you asked today or to one of Dr. Belfort's team, or our tissue engineers? (Tissue engineering is not on quiz, but questions to them count.)
• Be able to explain (with a few exceptions that you don't have to explain) do colored substances have high electrical resistance?
• Does everything with temperature give off light?
• How does angular momentum play a role in understanding that the old model that "electrons orbit nuclei" cannot be true?
• Why might he Titanic be less likely to sink if it hit the same iceberg at the same speed in the same way, if it was built out of today's steel?
• Know something about the following classes of materials: steel, super alloys, titanium alloys, shape memory alloys, biodegradable metals - which materials are best used where and why?
• What are the advantages of lithium polymer batteries over traditional lithium ion batteries?
• Why are Ti, Al, and Mg used in laptops and air crafts?
• Why is Ti more expensive than Al?
• Useful terms, ideas, concepts:
• ev (electron volt)
• actuate
• phase (as used in context of metals; not 'solid liquid and gas'.)
• resistance
• black body radiation
• band gap
• conduction band compared to valence band
• photo electric effect
• emission spectra
• role of temperature in material ages (e.g. bronze age)
• contributions of Schrodinger
• marble in tube analogy for conduction and valence bands
• insulator, semi-conductor, and conductor
• diffraction (resolution benefits of light, xray, and electron)
• Connections to other guests - Dr. Koratkar (batteries), Dr. Palermo and Ullal (materials), Mr. Colwill (clean room) 

Helps and Hints

  The following paragraph comes from an article published this year in Nature:

The key to making stable [metal organic frameworks] MOFs is to use clusters of metal atoms as the nodes, rather than individual ions. The geometry of the clusters determines the overall architecture of the crystal, which can be held together by a cornucopia of organic linkers. The growing set of interchangeable Tinkertoy components makes MOFs much more adaptable than zeolites and enables chemists to design products with pores that have just the right size and chemical properties for specific applications. Today, there are MOFs that can withstand temperatures of 500 °C, or easily endure a week in boiling methanol; others have internal surface areas that are triple that of MOF-5, or pores large enough to accommodate chunky proteins³.

•    How does what you learned from Dr. Koratkar (Li ion batteries) and Dr. Ullal and Palermo (materials) help you interpret or better understand or visualize what is being said here. Use specific example, facts, or imagery that our guests shared
     It has been said that the field of engineering can be defined as “applying math and science cost effectively”.  With that in mind what elements of the scenario Dr. Silva shared with us show that he was acting as a “cost effective” engineer rather than doing fundamental scientific research.  In your answer, use specific scientific details about what he taught us.
      It has been said that scientific invention is “creating something” while engineering innovation is “creating something that others want to buy.” With that in mind, how is Dr. Koratkar innovating rather than inventing? In your answer, use specific scientific details about what he taught us.
  Be able to use the following terms in context

  Metal	Ceramics	Glass	Polymer	Body centered cubic	Face centered cubic
  Amorphous	Defect	Vacancy	Ductile	Brittle	Dislocation
  Ductility	Transparency	Translucent	Opaque	Elasticity	Conformation
  Plastic	Thermoset	Thermoplastic	Bisphenol	Short path condenser	Partial reflux condenser
  Electroplating	Scaling	Surface area to volume ratio	Gibbs phase rule	Biodiesel	Ethanol
  BTU	MTBE	Energy density	Power density	Oxidation	Thermal shock
  Heparin	Graphene	Graphite	Anode	Cathode

•  What was a key insight that Dr. Linhardt learned (and shared with us) about the role of federal government when an important pharmaceutical is thought to be or become in short supply

Materials Science and Engineering

Professor Ed Palermo & Professor Chaitanya Ullal

Materials Science & Engineering

Gave a lecture and demos on how different chemical structures and environmental variables affect a material’s properties. Civilization is determined by the advances in materials.

Types of Materials (characterized by performance, properties, processing and structure)

• Metals

• Pure metal (Groups 1-12 + Al, Ga, In, Tl, Sn, Pb, Bi, Po only)
• Ductility Varies
• Opaque
• Crystalline Structure
• Ceramics
• One metal and one nonmetal
• Brittle
• Opaque
• Crystalline Structure
• Glass
• Mostly Silicon Dioxide or “Silica” (Sand)
• Brittle (additives affect how much (Plexiglass / fiberglass) )
• Transparent
• Amorphous Structure
• Polymers
• Plastics
• Long hydrocarbon chains
• Most variable of all materials (Ductile, brittle, transparent, translucent, opaque, etc.)
• Types include PET, HDPE, LDPE, PVC, PP, Polystrene
• He showed us a demo of heat changing HDPE to LDPE

Structure

• Crystalline Materials

• Metals, Ceramics and Some Polymers
• Organized atomic structure
• Prone to defects
• Cubic Structure

• Primitive Cubic (Nothing but the edge vertices of the cube)
• Body-Centered Cubic (Extra atom in center of cube)
• Face-Centered Cubic (Extra atom in center of each face of the cube)

• Hexagonal Packing (Cannonball Problem)

• Most efficient method of stacking objects
• Each atom has six surrounding it
• Structures made of spherical components naturally pack hexagonally

• Amorphous Materials

• Glasses and Some Polymers
• Non-specific atomic structure

• Defects

• Vacancy
• Smaller/Larger atoms
• Differing number of neighboring atoms
• Dislocations – necessary in ductile materials – the dislocation propagates in response to pressure

Properties

• Ductility

• Object’s ability to change shape
• Brittle (Shatters easily) ←→ Ductile (Bends easily)
• Dependent on atomic structure
• Transparency
• Object’s ability for light to pass through it
• Opaque (Cannot see through) ← Translucent → Transparent (Can see through)
• Elasticity
• Object’s ability to absorb force, bend and reanimate back to its original shape
• Inelastic (Does not allow for bending) ←→ Elastic (Allows for bending)

External Factors

• Temperature

• Mostly affects ductility
• Demonstrated through rapid cooling by way of liquid nitrogen and shattering a plastic water bottle
• Demonstrated through rapid heating by way of a torch and blowing a bubble out of the heated plastic of a water bottle

Connections

• Cleanroom

• Structure matters (single crystal versus grain boundaries)
• Potential material change adds advantages and disadvantages
• SME:
• annealing to strengthen with regard to grain boundary structure
• Thermoset versus thermoplastic polymers
• Dr. Chen – polymers and polymer conformation (RNA and proteins)
• Dr. Koratkar – sometimes there are advantages to material defects

Chemical Engineering of Polymer

Dr. Jim Silva

Chemical Engineer at GE

Drying Aqueous Salts for Polyetherimide Monomer Synthesis

Basically what Dr. Silva was trying to do was create a thermoplastic  that could retain its structural integrity  up to temperatures of 180 degrees Celsius. He wanted this plastic to be light weight, as well as electro-platable which means it  a very thin surface of metal can be electro-chemically put onto it, giving it  shiny finish without  no corrosion. To make the polymer, he wanted to make a bisphenol into an organic salt. The product needed to be created in water, but because the rest of the process required water-free organic salt, the water had to be removed. It was, however,  fine to have the product floating in a non-aqueous solvent.

When they did the process for one bisphenol, it was well-behaved and resulted in fine crystals. The product was full of water to start with, but they needed  it to be dry. A boiling solvent wasadded and then a chemical was sprayed into the solvent. This caused evaporation and left behind the salt in the remaining solvent.

When this process was repeated with a biphenol, it resulted in big particles and caking on the walls. It was discovered that the new polymer was taking much longer to dry; therefore they needed to make the new polymer at a much higher temperature. With this approach, an extremely large amount of solvent would boil off with the water.

In order to fix this they changed from a short path condenser to a partial reflux condenser that allowed much of the condensate to return to the original mixture. The idea was to condense at a temperature that was warm enough to keep the water if vapor phase but cool enough to condense the solvent and return it to the mixture. But this process is never perfect so some water inevitably gets condensed and returned to the initial mixture.  Because of this, they believed that the partial reflux condenser would not work. They thought with the partial reflux condenser too much water would be left behind in the mixture, but then they did an experiment to see that wasn’t true. They recalled the Gibbs Phase Rule which gave the theoretical reason for what they observed- that by fixing temperature and pressure, the composition in the condenser would necessarily not change. As a result they reduced the wasted solvent by an enormous amount, making the process phenomenally more cost effective.

Terms

• ·         Thermoplastic- a material (usually resin based) that is rigid when cooled, but deformable when heated. The material can repeatedly be heated and cooled.
• ·         Cellulose –Repeating glucose units. Arguably the most common polymer on earth.  Cannot be digested by humans. Starch (easily digestible by humans) is also a  glucose polymer. However cellulose and starch link the repeating units in different ways, making a huge difference!
• ·         Bisphenol- a class of organic chemicals (organic meaning made from carbon, not meaning free of pesticide!) that is characterized by having two hydroxyl-phenyl groups.  Saying something is a “bisphenol” is to categorize it chemically like saying something is a carbohydrate or an alcohol or an ester.
• ·         Biphenol – A subtly different substance from the one referred to as a  bisphenol. Our guest used this to distinguish between two similar substances whose specific names he did not want to disclose.
• ·         Short path condenser – a condenser cools a vapor back into a fluid. A short path condenser removes that fluid from the original mixture. In our example, any solvent that is boiled off with the water gets removed from the process and then needs to be dealt with as recyclable or non-recyclable waste
• ·         Gibbs phase rule - essentially that degrees of freedom or things you can adjust in a process = number of phases minus number of components, plus two. So if T and P are fixed, the relative proportions of the mixture are defined, cannot change.
• ·         Partial reflux condenser –a condenser cools a vapor back into a fluid.  A partial reflux condenser allows some of that condensate back into the initial mixture to be reboiled. Because the solvent and water have different boiling points, the two  can be mostly separated using this process.
• ·         Ppm- parts per million. A term used to describe concentration, similar to percentage (parts per hundred)
• ·         Electroplating- coating something with a thin layer of metal through the use of electricity
• ·         Scale and scaling of a process- the larger the scale of the project, the more money and time it takes. More importantly, scaling a process is not as straightforward as it sounds. In this example doing something in the lab at the gram scale was simple, but doing it at the scale of metric tons posed many complications – large amounts of waste solvent, challenges to mixing and heating, etc. A classic example of scaling comes with the ratio of surface area to volume. Surface area increases at a squared rate, while volume increases at a cubed rate. In the case of mixing or heating, this has major implications.  Imagine how long it takes to heat a 3 x 3 x 3 cube has a surface area of 54 square units and a volume of 27 cubic units. A 30 x 30 x 30 cube has a surface area of 5400 square units but a volume of 27,000 cubic units. You can easily see that heat transfer, fluid dynamics, and many other process variables will be affected by this dramatic shift in ratios.

Connections

·         Dr. Linhardt- The chemical engineering process and scaling

·         Dr. Ullal and Dr. Palermo-  Discussion of polymers

---

Polymer process outline

·         Dr. Jim Silva, Chemical Engineer at GE

·        

·         He talked us through a real life problem and how he solved it:

o   Trying to produce a low-weight, electro-platable thermoplastic that could hold up to temperatures of 180 C.

§  Wanted to make a bisphenol into an organic salt that could then go on and be used to make the polymer

§  Creating the product required water but rest of process needed water-free organic salt

§  But it was OK to have desired product floating in a non-aqueous solvent

o   Scaled up a lab process for one particular bisphenol and it worked fine

§  Needed a dry product but it was full of water

§  So add a large amount of boiling solvent

§  Sprayed wet chemical into boiling solvent

§  Water and vapor would evaporate, leaving desired salt behind in remailing solvent.

§  Some of solvent would boil off too, but this was condensed by short path condenser and then treated (not reused in process.) The loss of solvent was OK as it wasn’t so much that the process became cost prohibitive.

o    But when they tried to repeat the process for a different biphenol (not bisphenol) they got big chunks of salt caked to the walls, not fine particles suspended in solvent.

o   Analyzed situation and discovered newer polymer was taking much longer to dry at a given temperature so needed to make the new polymer at a much higher temperature, but this meant way more solvent would boil off with the water. Way more!

o   Came up with a solution (details not listed in this outline)

·         Terms

o   Thermoplastic

o   Cellulose

o   Bisphenol

o   Biphenol

o   R group (as in HO-R-OH)

o   Short path condenser

o   Thermos gravitational analyzer

o   Materials balance

o   Gibbs phase rule – essentially that degrees of freedom or things you can adjust in a process = number of phases minus number of components, plus two. So if T and P are fixed, the relative proportions of the mixture are defined, cannot change.

o   Partial reflux condenser

o   ppm

o   electroplating

o   Scale and scaling of a process

o   Chemistry versus chemical engineering

o  

·         Connections to other guests

o   Linhardt (scaling, process simplification, cost effectiveness etc.) Others:

Bio-diesel

David Connor and Brian Murray and Ray,

Bio-diesel (Chemical Engineering Dept.)    11/20

Terms:

·         Biodiesel-A fuel source produced from vegetable oil, fats, or grease

·         BTU’s-British Thermal Unit equivalent to 1055 joules; amount of energy to raise 1 lb of water 1 degree F

·         Ethanol-Ethyl alcohol, a two carbon alcohol found in fuels and found in liquor. Typically liquor has a maximum of 40% ethanol (diluted with water). The ethanol is very purified through distillation.  Ethanol used for fuel is essentially just ethanol, but not in a very pure form, so it tastes worse than food-grade alcohol (if that’s possible!)  Ethanol is typically mixed into fuel at a 10% content to oxygenate the gasoline so that it can burn more cleanly and meet the Clean Air Act amendments of the early 90’s. Until the mid 90’s MTBE was typically chosen for this purpose but in the late 90’s MTBE was found to be leaking into drinking water. This added a terrible taste to the water. It is unclear if MTBE is carcinogenic.

Social value-Some emissions created by biofuels are  considerably less than that of traditional diesel , reducing pollution produced by vehicles. http://www.crimsonrenewable.com/emissions.php  Specifically, net carbon emissions are less because the carbon in biodiesel comes from plants, a renewable source. (For a gram of carbon  to be released by combustion that same gram of carbon had to be  taken out of the atmosphere by photosynthesis for a net carbon emission of zero.)  This could be a useful alternative for fossil fuels in the case of a shortage or to just reduce green house gas emissions IF the biodiesel is made from used cooking oil. If the biodiesel is made from UNUSED cooking oil, its benefit is likely reversed by the deforestation it causes. (cutting down trees to grow oil-producing crops.)

Government and economics

Biodiesel could potentially reduce the reliance of the US on foreign oil, relieving some political tension.  It may also possibly reduce the cost of fuel, as fatty food wastes are abundant in America. There are about 3 billion gallons of waste fuel oil generated by the US each year.  Americans use 100 billion gallons of gas in the same period. So we would have to grow oil crops. The big issue there is  that there is some risk involved with both our major fuel and food sources being the same.  If there is a shortage then both are in trouble. Also, this would set up a trade off in resources between fuel and food ; some fraction of the water and farmland that could go to produce food would go to produce fuel instead.

Concepts continued:

·         Carbon REcycling International is a company that uses CO2 and water to make methanol products, mostly fuel for flexibly fueled (FF) cars.  One possible issue with FFcars, that I found, is that methanol is slightly corrosive, leading to increased wear on certain parts.  This process also solves the food/fuel source issue, as it is not produced from feedstock, but from CO2 and water.

Connections

o    Borton and Cleanroom and Dehnert (renewable energy,solar)

o    Dr. Silva and Dr. Linhardt (Scaling up production of a product)