Why ATP Meters Don’t Work For Microbes

Despite the less than clear marketing efforts by the makers of ATP(adenosine triphosphate) meters, the application of ATP bioluminescence is not an indicator of microbial contamination since it does not specifically measure bacteria, viruses or fungal spores. ATP bioluminescence for hygiene monitoring applications is an effective test for general hygiene and the verification of cleaning procedures, but is absolutely not appropriate for determining microbial contamination.

This from the maker of the most successful brand of ATP meter:

“ATP test is a direct, objective method that detects product residues on surfaces, and that the test is not intended to be a direct replacement for the traditional cultural microbiological test. Put simply, ATP hygiene monitoring is a product residue test, not a bacteria test.
ATP is the universal energy carrier and is found in all living organisms from the food we eat, our own body fluids and micro-organisms. The ATP content of foodstuff and body fluids is very large (usually millions of times greater) than that of microorganisms. This is largely due to the size differences but is also a function of metabolic condition.
Can the ATP test detect bacteria? Yes, if they are present in large enough numbers (typically > 10,000 cfu /ml; Stanley, 1989; Kyriakides et al., 1991, 1994) and there is no ATP from any other sources. Similarly the cleaning standard for product contact surfaces in the food industry is typically <100 – 800 cfu/100cm2 (Dillion and Griffiths, 1999) which is below the detection limit of ATP test. Accordingly performance claims for ATP tests for hygiene applications based solely on the detection of numbers of micro organisms are irrelevant.”

At best, ATP meters can show trend lines of corresponding organic reduction, and OxiTitan will progressively reduce all organics so you can see this. We demonstrate this effect as a biofilm reduction study ( please see our test under Microbial Lab tests elsewhere on our website). However, it is not food residue that gives us infectious disease, but pathogenic microbes. Microbes can exist without the gross quantity of ‘dirt’ that ATP meters can show.

Simply, just because an ATP meter reads ‘low’, it doesn’t mean there are no microbes.

Ref: http://www.hygiena.net/docs/atp_myths.pdf

One area which we at EcoActive Surfaces place a lot of emphasis is on application method. Because OxiTitan is not dependent on great film thickness for effectiveness, but instead needs a very thin even dispersion onto the substrate, conventional ‘painting’ methods are not the ideal. Excess of our coating does not add benefit, but instead increases cost per square foot/meter and may even have negative cosmetic effects, i.e. decreased transparency. We desire the very smallest droplets, evenly dispersed, so there are minimum voids between nanocrystals. That’s why we pay so much attention to fine atomization and recommend electrostatic spraying if possible.

One big issue is that even at the microscopic level, particles flow to the edge of a droplet during evaporation leaving areas uncovered. This is clearly visible in water spots we commonly see, as the minerals are left forming an outer ring, even in raindrops.

Here are some numbers to wrap your head around:
Although the percentage by weight in OxiTitan’s ready-to-spray coating is 98% water by weight, it still contains immense, almost incomprehensible, numbers of nanocrystals in suspension. A single liter (a little more than a quart) of OxiTitan contains around 2.75 sextillion nanocrystals. Sounds like a lot and it certainly is. Well, I had to look up ‘sextillion’, but it turns out that is a billion trillion or 1 followed by 21 zeros!

Let’s bring that down to a more manageable number. Raindrops average about one milliliter in volume, or 1/1,000th of a liter. So just a raindrop sized droplet of OxiTitan has an incredible several million trillion nanocrystals.

In this video you can see evaporation of water and the movement of particles to the edges, leaving voids with no particles. And this is just a very tiny droplet, 1 millionth of a liter, about a 1,000 times smaller than even the average raindrop I mentioned before.

http://www.youtube.com/watch?v=vXMJI3ugvvQ&feature=related

However, the bigger droplet, the more nanocrystals that just stacks up on the “coffee ring” of particles at the droplet edge and leaves voids.The voids left by evaporation of droplets are more pronounced as the droplets get bigger. Here is a “coffee ring” demonstration of how particles are moved to the edge of the droplet leaving much of the area ‘uncoated’.

http://www.youtube.com/watch?v=zMHNm7OEICw

The takeaway here is that OxiTitan functions at an incredibly minute scale and care needs to be taken to ensure an even coating. Meaning very small droplets, evenly dispersed.

And now you know what a sextillion is.

The safety of our products is a subject near-and-dear to us, since OxiTitan does not use any poisons or toxins (unlike all other antimicrobial products) to accomplish its self-cleaning magic. While we don’t advocate ingesting OxiTitan, it is important to realize just how safe and common nanoscale TiO2 is.

We use this mineral in everything from coloring milk, cake frosting, toothpaste, paint, paper, and the ‘M’ on an M&M, to use as the safest of sunscreens on our skin. This is not some new thing, but dates from nearly a hundred years ago. TiO2 is one of the most studied minerals in history, and is universally recognized as safe as food. And although the term ‘nanoparticle’ may be relatively new to our vernacular, humans have been safely eating TiO2 for generations since large scale production began in the early 1900’s. Here it is pointed out that 36% of all the TiO2 we have been safely eating is in nanoscale.

By Charlie Schmidt
Science & Technology

Sweet, Sweet Titanium
Candies contain high levels of the whitening compound titanium dioxide.

Used mainly as a whitening agent, titanium dioxide is a common additive in foods, paints, and personal care products. But scientists know little about how much TiO2 appears in these products, and that lack of data hinders studies of the chemical’s potential health effects. Now researchers have conducted the first analytical study of TiO in U.S. commercial goods, finding some products that contained almost 10% titanium by weight
“Risk assessors need more data on titanium exposure in people,” says Paul Westerhoff, of Arizona State University, who led the study. “Our study aims to fill in the gaps.”
Westerhoff and his colleagues analyzed foods, such as candy, chocolate, and dairy products, as well as personal care products, such as toothpaste and sunscreen. The researchers quantified titanium levels in the products using mass spectrometry. Concentrations in personal care products ranged from 1% to almost 10% titanium by weight. Among the 89 food products tested, white candies and other white-colored sweets, such as doughnuts, had the highest titanium levels, up to 340 mg per serving. Based on data on the consumption of such sweets from the National Diet and Nutrition Survey in the U.K., the researchers concluded that children consume two to four times as much titanium as adults do.
The team also found using scanning electron microscopy that 36% of the titanium in food was in nanoparticle form, with particles measuring less than 100 nm. Based on those observations, Westerhoff says food sources likely account for the vast majority of titanium nanoparticles discharged into the environment by wastewater treatment plants. Researchers next need to understand the health risks posed by this nanoscale fraction, he says.

Chemical & Engineering News
ISSN 0009-2347
Copyright © 2012 American Chemical Society

We frequently see these articles that purport to show the danger of various nanoparticles in the environment. Well-meaning and of definite value since there are a variety of new materials that have been developed that have higher toxicity in the nano form than the macroscale.

However, it needs to be made clear we should not have irrational fear of all things nano! Our natural world is filled with nanoscale particles of all types, including the ingredients in OxiTitan: titanium dioxide, zinc and silica. These minerals are ubiquitous in our natural world in both large scale and small, from rocks to pebbles, from dust and powder to nano sized. They are in the foods we and generations before us have consumed and myriad studies have shown their continued safety.

Our recent ability to create consistent nanoscale materials is a wonderful way to utilize the special attributes which these minerals have. They have them whether made by the natural grinding of the larger scale rocks or through the computational chemistry we employ at EcoActive Surfaces. And we take their safe use in our world very seriously.

When researchers state that their study shows a hazard or toxicity for nanomaterials, one really needs to evaluate the testing methodology. What is the dose? Dosage matters. Two aspirin are a boon to health, two dozen will kill you. Exposure to almost anything, even water, in high dosage can be detrimental to plants, animals, and humans. Studies look for the ranges in which material exposure can be hazardous because that is how we set our safety standards, but we should be cautious not to extrapolate extreme conditions to typical environments.

Next, what is the means of exposure? It is well known that inhalation of micro fine dust is hazardous, and one of the reasons we only sell OxiTitan in a colloid of water, so that the only possibility of exposure is when the coating is applied. Standard protection (N95 mask) should be worn to avoid accidental inhalation of the droplets during application.

Many safety research studies expose lab animals to free nanoparticles by inhalation, injection, ingestion or other direct means in very high does to test for reaction. Concentrated direct exposure to unbounded nanoparticles in mega dosage is not how we find them in our everyday environment, but certainly a possible concern in manufacturing, so these ranges are good to know.

Once OxiTitan is applied to a surface and the water that is the water carrier evaporates, the nanoparticles bond to every nook and cranny of the substrate forming a matrix of OxiTitan and the surface material. I have discussed this incredible bonding strength in an earlier blog, but suffice it to say, once applied, the only way to remove OxiTitan is to remove it with the actual surface material itself.

The amazing thing is, from a safety point of view, is that even when abrading or frictionally removing the applied nanocoatings, the particle that come off are not solitary nanoparticles, but attached to the surface material itself. In a word, it is the same dust you get anyway. The particles are one and the same with the material to which it is applied.

Let me be clear: Once OxiTitan is applied, there is no more exposure to nanoparticles than would be possible from the same surface without the coating.

For my friends working on their continuing education in this field, here are two papers and a couple of relevant quotes from the study conclusions.

Characterization of Nanoparticle Release from Surface Coatings by the Simulation of a Sanding Process
Daniel Göhler, Michael Stintz*, Lars Hillemann and Manuel Vorbau

“First, results show a considerable generation of nanoparticles during the sanding process. However, no significant difference could be observed between coatings containing and not containing nanoparticle additives. This conclusion agrees with the results of Koponen et al. (2009) from the total particle emissions of a commercial hand-held sander. TEM images of precipitated swarf particles show that the generated nanoparticles are rather made up from matrix material, which contains the embedded additives.”

http://annhyg.oxfordjournals.org/content/54/6/615.long

Sanding dust from nanoparticle-containing paints: Physical characterization
Koponen, I. K.; Jensen, K. A.; Schneider, T.

The Koponen paper concludes: “Addition of nanoparticles caused only minor changes in the geometric mean diameters of the particle modes generated during sanding of two paints doped with 17 nm TiO2 and 95 nm Carbon Black nanoparticles as compared to the size modes generated during sanding a conventional reference paint.”

http://www.particleandfibretoxicology.com/content/pdf/1743-8977-8-22.pdf

Logic prevails. It makes perfect sense that the use of an antimicrobial coating on clothing worn by healthcare workers would decrease microbial contamination on those items of apparel. While the organo silane (ammonium chloride) solution used in this study has limitations in durability( detergent washing removes organo silanes) and skin irritation and allergic reaction( it is chlorine based) and is using the ‘treated item’ exemption for use of the word antimicrobial, the application is a good one and one which we are exploring. Studies have shown photocatalyst coatings to be long lasting (20 plus commercial launderings) and broad spectrum (organo silanes are largely ineffective against viruses).

Of course, with OxiTitan one needs not limit the treatment protocol to just what you’re wearing, but also all the surfaces the healthcare worker, patient or visitor might have contact with: doors, chairs, bedside tables, call buttions, privacy curtains, walls, sinks. Essentially everything within and including the 4 walls.

INFECTION CONTROL TODAY:The use of antimicrobial-impregnated scrubs combined with good hand hygiene is effective in reducing the burden of methicillin-resistant Staphylococcus aureus (MRSA) on healthcare workers’ apparel and may potentially play a role in decreasing the risk of MRSA transmission to patients, according to a new study from Virginia Commonwealth University researchers.

Previous findings have shown that hospital textiles may contribute to the transmission of pathogens through indirect contact via the hands of hospital staff and that antimicrobial textiles may reduce the bioburden, or the number of bacteria living on a surface before sterilization in clinical settings.

Led by Gonzalo Bearman, MD, MPH, associate professor of internal medicine in the VCU School of Medicine and associate hospital epidemiologist at the VCU Medical Center, the study “A Crossover Trial of Antimicrobial Scrubs to Reduce Methicillin-Resistant Staphylococcus Aureus Burden on Healthcare Worker Apparel,” is currently available online and will appear in the March issue of the journal Infection Control and Hospital Epidemiology. “We strive to study infection prevention interventions that are simple yet effective for the reduction of health care associated infections,” says Bearman. “The goal is to affect change or implement risk reduction by methods that are both easily implemented and sustained.”

In the study, 32 healthcare workers wore four pairs of identically appearing control scrubs and study scrubs impregnated with an antimicrobial, or germ-killing, compound over the course of four months, washing them regularly. Participants also received identical hand hygiene educational sessions every four weeks, and researchers assessed compliance with hand hygiene practices.
Researchers conducted once weekly, unannounced, garment and hand cultures of participants at the start and end of each shift where they obtained two samples from the garment’s abdominal area and cargo pant pocket – two areas of high-touch and high bacterial colonization.According to Bearman, although the scrubs did not impact the degree of MRSA on the healthcare workers’ hands, the antimicrobial scrubs were effective in reducing the burden of MRSA on healthcare worker apparel.

“It is critical for healthcare workers and patients to understand that the environment—including inanimate surfaces and apparel – is not sterile, and is frequently a reservoir of drug resistant bacteria,” says Bearman. “Meticulous hand hygiene at the point of patient care is critical for reducing the risk of a hospital-acquired infection.

“If widespread antimicrobial scrub use were added to existing infection prevention strategies, a further decrease in hospital acquired infections may occur by limiting the cross transmission of pathogens via apparel. The actual impact of antimicrobial scrubs on hospital acquired infections needs further study,” he adds.

One of the many remarkable properties of our functional OxiTitan coatings is hydrophilicity: the photo induced sheeting of water on a surface. You can read more about this on the website but one of the many positives of this is extremely effective reduction of heat loading by enhanced evaporative cooling. The concept is simple: just like humans that use a thin film of water to cool us off (perspiration), one can cool a building, particularly ones with large glass surfaces, by letting OxiTitan change water into a thin film that removes latent heat through evaporation. Cool. Really, cool!

We’ll let those of you who want to investigate this further. Here are two links to prove the science.

First, the results of a 2 year study in Japan on a variety of buildings that clearly demonstrated air conditioning cost reductions of 10-30%

http://tinyurl.com/6wjctyh

This is for you engineers out there that want to wear out a slide rule (do they still make slide rules?): The actual computations and modeling to determine the loading and reductions.

http://tinyurl.com/7do2vy6

Unfortunately, even if surfaces are coated with OxiTitan, influenza can be transmitted by aerosol and direct contact. If you are feeling sick, go to the doctor, but don’t come to work or shop in my grocery store. Don’t be that guy!! If you really want to do the right thing, go get your flu shot. Vaccinations do work, and the danger infinitely smaller than getting the flu. So be a good neighbor.

DON’T BE “THAT GUY”: REMEMBER FLU ETIQUETTE

National Foundation for Infectious Diseases teams up with the Emily Post Institute to educate about spreading manners, not influenza (Tweet this)

BETHESDA, MD (January 17, 2012) /PRNewswire/ — During flu season, when fever, aches, and chills hit, it is easy to forget one’s manners. A recent survey of more than 1,000 Americans found that nearly two-thirds (64%) of those who had influenza in the past three years admit to being “That Guy,” who despite experiencing flu symptoms, continues to go about his/her daily activities.

As part of its “Are You That Guy?” influenza education campaign, the National Foundation for Infectious Diseases (NFID) is partnering with the Emily Post Institute to remind Americans to do the responsible thing during flu season and practice behavior that will help limit the spread of influenza, a highly contagious virus. The campaign also reminds Americans to see a doctor quickly if flu strikes. The campaign offers flu etiquette tips for managing common situations where the flu virus might be shared from one person to another, such as shaking hands during a business meeting, over a family dinner, or when faced with a fellow airplane traveler who is showing signs of flu.

“Most of us try our best to be considerate and do the right thing,” said Anna Post, great-great-granddaughter of Emily Post and co-author of the 18th edition of the Emily Post’s Etiquette book. “While people recognize that the flu virus spreads easily, they admit to tossing proper etiquette aside when they have the flu.”

The survey found that while a majority (81%) agree that a person with the flu should cancel social obligations when she or he is sick, two-thirds (64%) of those who had the flu in the past three years admit to being “That Guy,” who despite experiencing flu symptoms, continued to go about his/her daily activities.

“Every year, millions of Americans get the flu. We are all personally responsible for controlling its spread,” says Susan J. Rehm, M.D., NFID medical director. “The CDC recommends flu vaccine as the first and most important step in preventing influenza, as well as good hygiene and seeing a doctor for possible treatment with prescription flu medicines if symptoms arise. It’s important to know the symptoms of the flu so individuals can visit a doctor quickly to get properly treated before they risk spreading it to others.”

Only one-third (36%) of people surveyed would call their doctor if they thought they had the flu. Influenza is a highly contagious viral infection of the nose, throat, and lungs. Influenza occurs most often in the late fall, winter, and early spring. Flu is a serious infection which is associated, on average, with more than 200,000 hospitalizations, thousands of deaths every year in the U.S. and substantial medical costs.

“No one wants to be ‘That Guy’ who spreads the flu to family, friends, or colleagues,” said Post. “Knowing how to politely cancel an event you’re hosting or how to avoid shaking your client’s hand because you’re sick can be difficult and potentially awkward. By following appropriate flu etiquette, we can all play a role in preventing the spread of the flu virus.”

The survey found nearly four out of 10 Americans (37%) are uncomfortable telling “That Guy” that he/she is sick and should stay away from others. The Emily Post Institute recommends the following flu etiquette tips to handle common situations with social grace:

In the workplace: If you have flu symptoms at work, let your boss know right away that you need to get to the doctor. Just let him or her know, “I don’t feel well—I need to see a doctor. I think I might have the flu.” Better to have others pitch in while you’re gone than risk others on your team becoming sick.
In social situations: Normally it would be rude to cancel on a dinner party or big event at the last minute, but if you’re sick, call with your regrets and instead, go see your doctor.
Air travel: It’s tough to point out someone’s behavior mid-flight with hours left to go. However, flu is highly contagious. If there’s no other seat available, consider saying, “I can see you’re not feeling well—would you mind covering your mouth when you cough? Thanks.” Most people when prompted are eager to show good manners and do the right thing.

When a US Fortune 500 company finally adopts some ‘new’ technology, the press loves it. EcoActive Surfaces has a far superior photocatalyst coating, OxiTitan, that functions the same as the Alcoa coating discussed in the following article. Big differences: OxiTitan can be easily and inexpensively applied on virtually any existing surface. You don’t need to build a new building covered with expensive Alcoa panels to get the same benefits of pollutant removal and self cleaning. Even if the building owner is not impressed by the improvement in his and his neighbors air quality, he can appreciate the savings in reduced maintenance.
Additionally, not only is OxiTitan is higher in photocatalytic oxidation power than the ToTo product Alcoa uses, but OxiTitan also will work indoors with just ambient visible light. All other photocatalyst coatings require the UV in sunlight. OxiTitan uses makes efficient use of both ultraviolet or visible light.

From Forbes Magazine
Technology
Air Freshener
Todd Woody, 06.06.11, 6:00 PM ET
Your trophy building may score green points for the wind turbines on the roof, the car charging stations in the garage and those waterless urinals. But does it eat smog? Upping the environmental ante in the corporate sustainability sweepstakes, Alcoa has unveiled building panels that it says clean not only themselves but also the surrounding air. “Candidly, when you first learn about this technology you think, ‘Wow, you’ve got to be kidding,’” says Craig Belnap, president of Alcoa Architectural Products, at the aluminum giant’s New York City offices in the iconic Lever House.

That does sound way sci-fi, so Belnap reaches for a prop, a mini-me version of an aluminum-skinned building panel like you’d find on a skyscraper in Anywhere, U.S.A. It looks utterly unremarkable.

But invisible to the naked eye is a coating of titanium dioxide on top of the silver paint. Titanium dioxide particles serve as photo catalysts, and when struck by sunlight their electrons become supercharged and interact with oxygen and water molecules in the air. That interaction releases free radicals that break down organic material–dirt, in other words–on the panel’s surface. The panel, dubbed Reynobond with EcoClean, works the same magic on pollutants such as nitrogen oxide in the surrounding atmosphere, according to Belnap.

“It’s really those free radicals that do all the work,” he says. “They’re the components that attack organic material and oxidize them down to harmless compounds that can eventually be washed away by rainwater.” That happens because the titanium dioxide particles also create what is called a hydrophilic surface that allows water to cascade off the panel in sheets rather than bead up. What’s not washing off the building and ultimately into rivers and oceans, of course, are the chemicals used to clean traditional building facades.

Alcoa estimates that the self-cleaning EcoClean panels can cut a building’s maintenance costs by a third to half. In early 2009 Alcoa tested the new coating on four Reynobond panels, which are sheets of a metal such as aluminum, stainless steel or copper that sandwich a thermoplastic. They installed the aluminum panels on a gas station canopy in the Atlanta area. Four months later they were still clean.

Alcoa won’t divulge its secret sauce or how much it spent on the R&D effort. And the company is cagey about the size of the potential market but believes it can capture a good chunk of the 14 billion square feet of aluminum or steel panels installed each year, as it currently faces no competitors for self-cleaning buildings.

According to Alcoa, 10,000 square feet of EcoClean panels will eat 5.9 pounds of nitrogen oxide a year, or 5.3 cars’ worth a year. “That’s about the same air cleansing of 80 trees,” Belnap says. “If a fraction of [panel] surfaces use the EcoClean product, it would be the equivalent of planting several million trees.”

Alcoa began the project several years ago after some decidedly old-school clients approached the company about greening up their images. “We had a number of our petroleum and gas customers ask us if there was something we could do to help them make their brand more striking and cleaner,” says Belnap.

Alcoa turned to Japan’s Toto for some help. Toto had developed very popular titanium dioxide coatings used widely throughout Japan, but its coatings had to be applied after the manufacture of the building panel, a labor-intensive and expensive endeavor. A breakthrough came when Alcoa developed a way to integrate the titanium dioxide coating into a high-speed manufacturing process that paints coils of aluminum. “Our current research shows it can be applied to all painted surfaces,” says Belnap.

Even cars? Theoretically, yes, but not anytime soon. “There would be a substantial amount of research to be done to get the kind of durability needed to cover other kinds of surfaces.”

EcoClean panels will command a 4% to 5% premium over the installed cost of conventional versions, a price Alcoa believes customers will be willing to pay for the long-term return on investment as well as the monumental boost to their green image.

Two pilot projects are under way in Europe and North America with customers Alcoa declined to identify. But Belnap does show off a new faux-wood-grain building panel. “In Europe we’re using the tagline ‘How much forest can I build?’” he says.

EcoClean: The Chemistry Of Cleaning
Mix titanium dioxide and sunlight and wash away pollution.

1. FREE RADICALS RELEASED
When sunlight strikes the titanium dioxide particles embedded in Alcoa’s EcoClean building panels, their electrons get charged. The energy is transferred to oxygen and water molecules in the air, forming free radicals.

2. SEARCH AND DESTROY
The free radicals attack and oxidize organic pollutants on the panel and in the surrounding atmosphere, breaking them down into benign compounds.

3. SUPERSLICK SURFACE
Free radicals cling together on the EcoClean building panel, creating a slick surface that allows rainwater to wash off in sheets rather than form beads. As the water cascades off the building, dirt remaining on the panel is washed away.

We are often asked about the binding strength of OxiTitan and why it displays such tenacity in affixing to virtually any surface.

Generally, a nanoparticle’s size and surface characteristics determine the kinds of materials with which it will bond. For us, there are really two things going on, one is physical bonding and the other is chemical. The term used physio-chemical bonding.

First, nanoparticles are incredibly small and even though we think of some surfaces as being absolutely smooth, they are not. Here is a micrograph of the surface of glass (amorphous silica). We ‘see’ it as perfectly smooth, no pores, etc….. but it is not. This is true of virtually all surfaces.

Note the measurement of 4 microns, lower left. 4 microns is 4,000 nanometers. Visualize how many nanocrystals of OxiTitan, at 7 nanometers in size, can infill these ‘defects’. In a perfect deposition( not likely), that 4 micrometer hole can hold over 500 nanocrystals of OxiTitan on its surface. This lodging in and on the nooks and crannies is simply physical bonding.

This infilling of defects is also what makes the addition of nanocrystals give substrates additional abrasion resistance. Nano materials infilling the defects make the substrate more resistant to the fracturing that occurs from both impact and friction. Like putting putty at the head of a crack, it arrests further fracture and substrate degradation. Cool.

To get scale, think of the typical surface as being like looking at the Rocky Mountains from an airplane. By scale nanoparticles of OxiTitan are like trees on those mountains. You may wipe the surface for example, but you are only ‘topping the mountains’, and you must wear down to the bottom of the valleys to remove all the nanocrystals. This is also why it is hard to pinpoint wear rates, since every substrate has different texture and hardness. Scientific accurate statement is that OxiTitan wears at the same rate as the surface to which it is on.

Figure 9. Scanning electron micrographs of steel surfaces. A – annealed stainless 316 (Valco); B – the same tube after forming into the serpentine shape; C – hypodermic stainless 304 (Coopers Needle Works); D – hypodermic stainless 304 (SGE). Absolute magnification: 10k.

Above you can see even the ‘smoothest’ of surfaces like annealed stainless which is very smooth due to its chromium oxide passivation layer, still has lots of texture.

Now, chemical bonding is also occurring. The immense surface area to mass ratio of nanoparticles make them highly receptive to chemical bonding: the exchange of electrons to a stable state. Obviously this chemical bonding will vary with the chemical composition of the substrate, but the evidence is that this is pretty universal. Additionally, OxiTitan nanocrystals are unique in being a largely metallic crystal, with atoms of titania and zinc. We also include silica in the basic formulation to enhance binding strength
( nano-silica is even used to bond optical glass together).
The properties of metals suggest that their atoms possess very strong bonds. However, the ease of conduction of both heat and electricity show that electrons can freely move in all directions in a metal, particularly the semiconductors like zinc, titanium and silica oxides that we create in OxiTitan. Great for us because the goal is to present as many electrons to the surface of the nanocrystal( with a concurrent maximized surface area) when energized by light so as to be available for water-splitting, thus maximizing our photocatalytic performance.

Hope this helps, any input is welcome.

Now here is a great way to study anatomy: the biodigitalhuman. In beta version, this is a very cool interactive way of learning more about yourself from skin to skeleton and all the systems in between. Give yourself some time to play ‘doctor’ and enjoy!
Here’ the limk:

http://www.biodigitalhuman.com/