Atkins Physikalische Chemie Pdf To Jpg
Wake up super early, make a warm drink, and drink it while u r watching the sun rise. take a super long bath with music, a bath bomb, candles, magazines, etc!! - have a movie/tv day with ur fav snacks & treats!! - go for a long walk and pick some flowers to dry, press, or give to some1 u love!! - spend some time with animals!!
If u have a pet, play with it, pet it, love it!! Or, go to an animal shelter and play with all the animals there!! - host a lil fundraiser for a cause u care about! It doesn’t have to be much, maybe just sell some treats and donate the money to a charity u want 2 support!! - make some positive journal lists!!
Anwendung. als Referenzelektrode Quelle: Atkins/de Paula, Physikalische Chemie, 4. Auflage, WILEY-VCH Verlag, Weinheim, 2006, S.
Some suggestions: small things I love about myself, things that make me happy, kind things to do, etc! - head to a local farmers’ market and buy urself some potted flowers or herbs! Remember to water and care for them!! - go for a rly long walk!! Call it an adventure & explore ur hometown! - write a letter to a loved one!!
U can include little gifts like teabags, tiny candies, polaroids, etc! - clean a desk or table, light an aromatic candle, and take some time to really think. What’s on ur mind truly, hiding just beneath ur consciousness? Can u fix some of ur problems?
What’s makin u happy rn? - mix some natural scented extract w water in an old spray bottle! U can spray it around ur room or whatever!
Mint 4 balance, Lavender 4 relaxation, vanilla bc it smells sweet, etc!! - make a playlist on ur phone, or burn it onto a cd! Make it soothing & relaxing!
U can give some copies 2 ur family members or pals!! - put on some lipstick, stick out ur tongue in the mirror, take some cute selfies (if ur comfortable!) u r a beautiful work of art and u look just the way ur supposed to! - don’t 4get to get a good nights sleep, drink lotsa water, and love urself! - remember it’s okay to have lazy days.
It’s ok to relax. It’s ok to pamper urself. You are still moving and growing and learning, u r a tiny little plant with so much to give and to receive and you are always worth it. Here it is, babes: my highly requested mixtape how-to!!
HERE’S WHAT YOU WILL NEED:. iTunes + a disc drive.
Sharpie or other permanent marker. Collage supplies!. glue stick, magazine scraps, stickers, glitter, etc.
Decide your purpose. What’s it for? Who’s it for? Will you have a theme? What kinda music/genres fit with that theme? Compile the tracks into a playlist on iTunes. FILE NEW PLAYLIST Here are sum tipz for compiling your tracklist:.
I like to vary old + new music, genres, moods, etc. To make it flow, I like to place the songs in an order where each song somehow compliments or contrasts the previous track. Include a good mix of familiar tracks and new finds. Live versions of familiar songs are always a good idea.
DO NOT BE SCARED TO INCLUDE CHEESY POP SONGS. Consider movie soundtracks! Those are ALREADY like mixtapes!. 15 songs is a good # of tracks to shoot for.
Burn the CD!!! Insert a blank disc into your disc drive. FILE BURN PLAYLIST TO DISC 4. Wait 4 the disc to burn.
Grab a big ol snack while u wait. Make sure you don’t bump your computer while the disc is burning or the driver could fail. 🌸 DECORATE YER COVER, HUNY 🌸 This is obviously my fav part nnggg. My biggest tip is that collaging takes tons of practice to get a feel for.
The person you’re making the mix for will love it NO MATTER WHAT, so don’t sweat it. Here are some of my biggest tips on art directing yer new creation:. I start by cutting out a little less than 5″ by 5″ piece of plain card stock to act as a solid background.
A good title can MAKE a CD (and lend itself to some solid visuals). Have a small collection of magazines + clippings to go to for inspiration. My favs are 1980′s Nat Geo’s, “Oh Comely” (a British rag). To get my clippings, I look through a few issues and clip ANYTHING that relates to the vibe of my mix in any way. Sometimes I have a color scheme in my head or a specific imagine or mood. That guides my pics, but I’m always ready to deviate if something else grabs my eye. Sometimes simple covers with a big graphic and some dope patterns/color blocking are more appealing than wild ones, so don’t overthink it 6.
GIVE THAT BABY AWAY! Here are some covers I’ve made to give y’all some samples: If you follow this how-to, be sure to tag me in yer pics.
I’m sorry, this isn’t Jojo at all but I think I’ve had it for today. As a pharmacy tech, I’m tired of hearing “Well, I started to feel better so I didn’t finish them.” I always knew this but now as a Molecular and Cellular Biology major, I not only know why but how.
If you’re willing to heed my advice from the title, good; be on your way. If you need to know more, keep reading. It’s widely known–to some extent–that not completing a regiment of antibiotics can result in resistant bacteria, or even super bacteria. But in an infection, you already have resistant bacteria lurking. Not taking antibiotics doesn’t literally create resistant bacteria. So how, then, do the antibiotics take care of the resistant ones? A lot of antibiotics aren’t bacterialcidal: They don’t actually kill them.
Many inhibit growth by some mechanism depending if the bacteria is gram negative or gram positive. For example, penicillin inhibits growth by disrupting the formation of a peptidoglycan layer on gram positive bacteria. Others target the LPS layer on gram negative ones.
This keeps the non resistant bacteria at bay. So what kills the resistant ones? Your immune system. Antibiotics buy time and energy for your immune system to recognize and destroy the resistant strains. Your immune system is intelligent in that sense and can form antibodies for new illnesses.
It’s important to give your immune system this time because bacteria grow, mutate, and transfer genetic material at astonishing rates. If you wanted to look at a microcosm of the mechanics that go into evolution, you’ve got it with bacteria. There are three methods aside from binary fission in which they transfer genes (I won’t get into the minutia of the form of informational material): Transformation, transduction and conjugation. In transformation, a bacteria can pickup lost genes from a ruptured and dead cell. Transduction is a way to transfer information via a viral vector.
In conjugation, genes are transferred through something called a pilus: It’s a bridge between two cells that pipes a copy of the information from one cell to another receptive cell and is the only method that doesn’t involve killing either cells. Resistant bacteria like to give around that resistance information like they’re burning a CD for their friends. So please finish your antibiotics if you’ve been given them. It doesn’t matter if you’ve started to feel better or even great. (Hey science people, If I’ve missed anything or even got something wrong, help me out.
There’s obviously lengthy stuff I’ve left out but I think I got the basics). Well I cannot really tell you EVERYTHING on what you should send to your pen pal but hopefully this will give you an idea: 1. (make their day) 2. Pictures (whether it’s of you or something you just really like/find pretty) 3. Post Cards from places you visit 5.
Pencils/Erasers/Pens (They don’t have to be expensive or anything. It’s the thought and effort that counts!) 6.
Washi Tape (You can use a popsicle and wrap the washi tape around it. That way your pen pal can use washi tape you own!) 8. If you like to draw, you can draw anything on pretty paper and cut it out (maybe turn them into stickers?!) 9.
Make magnets! Make your own bookmarks with the things your pen pal and you have in common. Or maybe something you find cute 11. You can make pins and send them to your pen pals 12. Send them bracelets or a necklace (You can even make that) 13.
Make a CD of your favorite playlist (Burn a CD of your fav. Cute hair pins 15. Souvenirs from where you are from/at 16. You can always get leaves or flowers and use tape that way your pen pals can save and see what your fav. Flower or leaf is?
Lol or maybe you just like being outdoors I can go on and on I hope this gave you an idea or maybe you might even try some of the things that were on this list. Whatever you’d like, just remember to have fun with it! ✨ some alive noah things ✨.
takes the steps two at a time. jumps the last three when going down. does not use shampoo marketed For Men. this boy smells like flowers. dropped latin after exactly one and a half class periods. Switched to spanish.
Never looked back. will burn you a CD for every life event. will write your birthday on his calendar.
once showed up to adele’s school in the middle of the day and claimed there was a family emergency so that he could check her out; they went and got gelato. doesn’t care about your shitty opinions. knows every possible make out spot on aglionby campus. aglionby’s #1 source for girl scout cookies.
the youngest czerny sister always has the highest sales in her troop. does peace signs in photos. Never clear if it’s ironic or not. Summary: (College!AU) In which you do something for Bucky that brightens his bad day. Pairing: Bucky x Reader Word Count: 1,923 A/N: An anon requested “reader does something spontaneous and romantic for Bucky that she doesn’t even think of as romantic!
And he is just floored by her thoughtfulness.“ This takes place between “The Little Things (Part Two)” and “The Get Together”. A track list for the CD mentioned in this part.
+ - thank you for existing and being my very best friend/editor You’re stuck in the middle of a heated debate between Bruce and Helen Cho about gamma radiation when Steve walks. He scans the dining hall, letting his gaze fall from one table to the next, before balancing his tray in one hand so he can rub his forehead.
As he does, he discreetly scans the room for a second time, reminding you of a lost child desperately seeking out his mother. 'Steve!” You call out, making sure your voice is loud enough to be heard over all the chatter. He turns around immediately, a relieved grin overtaking his features as he walks towards you. Summary: this is the first 5 (Part 1) of 10 ways Peter Parker shows he loves you, peter x reader. Alcohol consumption is mentioned in case that’s a trigger for anyone. A/n: I actually really liked this Idea and went with it.
For Masterlist click. I won’t write part 2 unless this gets a good amount of notes so please if you like it, like or reblog!
Peter turned the corner of the school hallway to find you furiously unzipping every zipper on your bookbag. You were searching for a pen through your entire bag and locker. You had history next and your teacher only allowed students to write all notes and assignments in pen. The bell rang, indicating that lunch had ended and you still hadn’t found a pen. Sighing loudly you closed your locker and were greeted by Peter.
“Hey” Peter smiled. “Hey” you greeted, throwing your backpack over your shoulder and slumping your shoulders. Beginning to walk towards the stairs, “Wait what’s up?” Peter asked aware of your slumped mood. You took three steps before turning to look at him, a step below you. “I just forgot a pen for class and I didn’t answer the pop question yesterday correctly, which means he will call on me to check all of my work- which I won’t be able to write because I don’t have a damn pen” you gushed out all in one breath. “ Easy, take mine” he handled you his only pen. “what will you write with them” you questioned, warily taking the pen. “I’ll figure it out when I get there” He said intertwining your hands together and leading you to class.
Atkins Physikalische Chemie Pdf To Jpg File
Peter rapidly tapped his fingers against the desk, spaced out from whatever the decathlon meeting was discussing today. He was counting down the seconds until the bell rang and he could rush to meet you outside your classroom. He knew you had to return the majority of your books today and he could only imagine the literal weight on your shoulders.
As soon as the obnoxious ring sounded throughout the room, he bolted out of the room. Flying down the stairs and taking a sharp right turn towards your class, he caught you just in the nick of time. You were walking out of class with 3 textbooks stacked over your arms and making small talk with Michelle. One of textbooks started to slip from your grasp and peter was at your side immediately picking up the fallen book. “Hey Parker” you greeted him. “Hey” he leaned in, kissing you and swiftly taking all the books onto his arms, and pulled away. “ Let me carry these for you” peter signaled towards books now resting in his arms. “God I love you” you sighed out while rubbing your sore arms. “I know” He shot back with a smirk. “Okay, Han solo I need to return these after lunch so meet me at the library” you pecked his cheek and turned to walk with Michelle. “He’s so whipped” Michelle said matter of factly and laughed. “Petre R u up” A text Peter received from your number at 10:30pm on a Thursday night. “Hey what’s up?
Are you okay?” He quickly straightened up and grabbed his phone it was unlike you to send these type of texts on a school night. At once, he received an incoming call from you He picks up and starts bombarding you with questions and to which you only answer “shhh I miss you Parker” slurring in last name a bit. “Are you drunk right now?” he asked quickly throwing off the covers and searching the room for a T-shirt. “Maybe, I’m at Liz’s, for a project, project for science, yep a project, I’m sleeping over and we may or may haven’t gotten into Liz’s dad’s liquor cabinet” You stuttered out. You knew it was a bad idea to get drunk on a school night but you underestimated the power of alcohol and how much of a lightweight you are. “He’s out of town, we are in the clear I miss youu” you giggled at something Liz said. “I’m on my way” Peter whispered into his phone as he snuck out through the fire escape window.
“no don’t come, you can’t come, no boys allow liz’s rule” you said. “ I just want to make sure you’re okay” peter says worrisome into his receiver. But how are you even getting here though? You don’t drive” you question. “Uh Uber” he says, pulling his mask over his face. On your one year anniversary, Peter gives you the typical flowers and love letter. Until you spot the CD attached to the back of the letter.
You look up at him to see the sheepish smile on his face. “You made me a mixtape?” you question already smiling. “ Yeah I memorize every song you every sang under your breath to and put them on a disc” he said staring at the ground now, blushing. You thought back to before you and Peter were even dating, when you were just bus partners and you sat next to him with your headphones in.
You knew you hummed into to quite a few songs but now you had realized you might have sung a few as well. You grabbed your laptop from your bed and slipped the cd right into the slot.
Nothing played on the first try nor the second or the third. You even tried playing it on your DVD played with no luck. “Maybe my computer disk reader is broken” you offered after seeing the look on Peter’s face. “No i just think I don’t know how to burn CDs very well, I knew I should’ve asked Ned for help I’m sorry for ruining the anniversary” He looked down at his knees. “Hey no you didn’t ruin anything Peter it’s the thought that counts here” You put your hand under his chin, “I’m serious this, today was really great” you assure him. Looking between his lips and his eyes you begin to lean in when music starts blaring from your laptop speaker, interrupting your moment. “Hey at least it works” You tease and roll on your side to scroll through different songs Peter picked out for you.
Peter snapped a picture of you leaning on the lunch tables deep in thought, the camera noise going off pulling away from your thoughts. “You taking pictures of me again Pete?” You point your fork at him accusingly, before grabbing another ball of noodles with your fork. He just nods examining the picture detail by detail as if he wasn’t sitting in front of the real thing. His lips twitches at the way you scrunch your eyes when you’re concentrated. He follows every curve on your face with his eyes. “oh come on let me see it, I hate off guard pictures I always look pissed off” you reach over the table and grab his phone.
You look at the picture then back at him, “just as a suspected, I look extremely pissed off at the ceiling.” Peter immediately chimes in that he thinks you look great. “Of course you did Peter, I could wear a sock on my head and you would tell me I looked amazing” you smiled at him caressing his kiss. ”Yeah true but i seriously think you look good in this one, its wallpaper worthy” he says like staring down at his phone again. “Only Wallpaper” you ask raising an eyebrow. Kagan cooperative learning timer tools kagan. “ You already know you’re my lockscreen and wallpaper” he rolls his eyes but nevertheless blushes. “Thought so, you’re mine too by the way” You smile before turning to playfully flip off Michelle after hearing her make gagging noises towards you and Peter. Please lmk if you want a part 2, aka the other five reasons, cause my most recent imagine flopped.
Received 27th May 2017, Accepted 27th June 2017 First published on 28th June 2017 Self-oriented anisotropic nanoparticles in nanoporous films were obtained by controlling the surface functionality induced by the organic amino acid derivatives adsorbed onto TiO 2 nanosheets. In particular, tyrosine-functionalized TiO 2 nanosheets were self-oriented in a nonparallel orientation with respect to the substrate plane owing to the following surface properties: (1) the ζ-potential, (2) hydrogen bonding, and (3) hydrophobicity due to the collaborative effects of segregative interactions from hydrophilic surroundings, i.e., water and oxide substrates. Although nanoporous films with both parallel and nonparallel orientations of TiO 2 nanosheets with respect to the substrate plane exhibited a similar internal surface area and porosity, evaluation of the electrochemical properties of TiO 2 films with non-parallel orientation showed a significant improvement in electron transport through the TiO 2 nanoporous network, as demonstrated in dye-sensitized solar cell devices. Introduction Nanoporous films composed of nanoparticles with large internal surface areas, high porosity, and nanostructured voids have attracted attention recently for their potential applications in photo-electrochemical devices, batteries, thermoelectric and photocatalytic devices, and solar cells. In the field of nanoparticle engineering, the development of facet-controlled anisotropic oxide nanomaterials, such as nanosheets, nanotubes, nanorods, and nanowires, has resulted in the development of a large variety of anisotropic oxide nanoparticles instead of conventional spherical particles. Recently, these anisotropic particles have been proposed as building blocks for the construction of novel nanostructured porous films.
This is because of the advantage that they offer of superior properties in carrier transport through the nanoporous material network and their ion diffusion properties in electrolytes filled in the void of the nanoporous films. These properties are due to their morphological ordering, in addition to fewer inter-particle connections through the nanoporous network compared with conventional random-networking spherical isotropic nanoparticles. This is especially true for applications in electrochemical and photo-electrochemical devices by assembling the nanoporous network with liquid or quasi-solid electrolytes.
To utilize the morphological advantage of the anisotropic materials, the desired morphology of the nanoporous network would be for their long axis to be perpendicularly orientated in films with respect to the substrate plane rather than the orientation being random. Perpendicular orientation of anisotropic nanomaterials was recently achieved by self-orientation of directly grown particles, nanowires, nanosheets, nanotubes, and others on substrates by utilizing solution phase growth techniques, such as hydrothermal, solvo-thermal, and anodic oxidation processes, which involve immersing the substrates in a precursor solution. However, these processes are not widely applicable in practical applications due to the drawbacks of limited coating area, less uniformity, and batch-to-batch-based slow processes. In contrast, a practically more feasible coating-based process involving anisotropic nanoparticle suspensions generally results in the parallel orientation of the longer axis of nanoparticles with respect to the substrates , owing to the minimization of the surface energy of anisotropic particles. Therefore, anisotropic nanoparticles mostly have a parallel orientation with respect to substrates fabricated by the coating process.
These parallel-oriented anisotropic nanoparticles sometimes do not show significant advantage of electrochemical properties over conventional spherical nanoparticles possessing a random network. For example, a high aspect ratio of nanorod TiO 2 revealed less effective charge transport in the nanoporous films due to their unfavorable parallel orientation with respect to substrates. A method to control the orientation of nanoparticles in the suspension has therefore been proposed based on electrophoretic deposition under a strong magnetic field. However, obtaining a large production area with a uniform film is still a challenge because of the complexity of the system setup. Another method based on convective self-assembly using dispersion suffers from the problem of sensitivity to the environment. Solvent drying and film preparation therefore take a long time. Scheme 2 Amino acid derivatives used as Phenylalanine (Phe), Glutamic acid (Glu), Arginine (Arg), Lysine (Lys), Cysteine (Cys), Glycine (Gly), Tyrosine (Tyr), and Histidine (His).
The paste with non-functionalized TiO 2 was prepared by the addition of α-terpineol and ethylcellulose in ethanol (2 wt% of TiO 2) suspension. These TiO 2 films were successively annealed at 500 °C for 30 min to remove the organic compounds and the solvent. We confirmed the parallel orientation of the TiO 2 film with non-functionalized TiO 2 on glass or FTO substrates by SEM and XRD. 3 Number density of self-assembled TiO 2 nanosheets with nonparallel orientation of the longer axis with respect to the plane of substrates counted in plane view SEM images (Fig. The driving force behind the non-parallel orientation is now discussed with the hypothesized mechanism of particle self-assembly, since many nanosheets with a non-parallel orientation gave the appearance of multiple sheets stacked together in SEM images ( and Fig.
Atkins Physikalische Chemie Pdf To Jpg Free
S2, S4, ESI). The adsorbed amount of Tyr on the TiO 2 nanosheets was determined to be below the saturated concentration of Tyr in water, ∼8 × 10 −4 M, (Fig.
This is limited by its low solubility in water, while the actual Tyr adsorption is much greater than the measured maximum surface concentration of 0.6 molecule per nm 2 determined at a Tyr concentration of ∼8 × 10 −4 M. This is because the actual experiment of particle assembly was performed beyond the saturation point of Tyr in water, i.e., Tyr was contained in the TiO 2 suspension with an equivalent molar concentration of 0.5 M in the experiment, while Tyr was observed as the solid in the suspension, which indicates that not all of the compound was completely dissolved in the solution.
Therefore, the surface concentration of adsorbed Tyr molecules could be much higher than 0.6 molecules per nm 2 as a result of the excess amount of Tyr dispersed in aqueous TiO 2 suspensions under the experimental conditions of film preparation. To characterize the surface properties of the TiO 2 nanosheets functionalized with several varieties of amino acids in the aqueous suspension, the ζ-potential was measured by the electrophoretic light-scattering method. The ζ-potential of the oxide surface typically shifted from positive to negative due to the deprotonation of the TiO 2 surface, corresponding to an increase in pH of the surrounding solution.
Correspondingly the titration process of the hydroxy group on the oxide surface depended on the pH of the surrounding solution. As a consequence, the pH-dependent ζ-potential of the oxide surface significantly influenced the repulsive electrostatic force between the particles. As reported previously, most of the TiO 2 samples, including bare TiO 2, revealed an isoelectric point with a pH value of about 7. It was, however, clearly observed that the absolute values of the ζ-potential varied with the amino acid, and therefore a few amino acids, including Tyr, exhibited a significant decrease in the ζ-potential. The low values of the ζ-potential presumably resulted in the particles aggregating in the suspension due to a decrease in the electrostatic repulsive force in the stable suspension of oxide nanoparticles. To observe the aggregation of the nanoparticles, dynamic light scattering of the suspension was applied in order to determine the diameter of aggregated nanoparticles in the suspension by utilizing the Stokes–Einstein equation. The results revealed that the Tyr-functionalized TiO 2 nanoparticles were still well-dispersed in the suspension, while a slight increase in particle size was observed.
This is probably an indication of aggregation due to smaller inter-particle repulsive forces compared with a non-functionalized TiO 2 suspension (Fig. 4 ζ-Potential of TiO 2 nanoparticles (0.01 wt%) measured with aqueous suspension in amino acid solution (0.09 mM) under a pH controlled by the addition of NH 4OH aq (0.1 M) into acidic suspension containing HCl (pH 2). We observed that self-assembly with non-parallel orientation of nanosheets with respect to the substrate plane was achieved in most cases with a hydrophobic amino acid of Tyr, Cys, and Phe among the applied conditions.
Here, we quantitatively examined the hydrophobicity of the TiO 2 surface functionalized by a series of amino acid compounds by means of contact angle measurements of water droplets on the surface of each amino acid-functionalized single-crystal rutile TiO 2. The substrates of single-crystal rutile TiO 2 were cleaned by EtOH under sonication, annealed at 500 °C, and then immersed in an equivalent 0.5 M aqueous solution of each amino acid without ammonia addition for pH control.
Although the single-crystal rutile and anatase nanoparticles may have a slight difference in TiO 2 surface properties for molecular adsorption, we focused on the qualitative examination of the surface of each amino acid-functionalized TiO 2. A high contact angle, corresponding to the hydrophobic surface, was consistently observed with the amino acid exhibiting relatively favorable behavior for non-parallel orientation of TiO 2 nanosheets with respect to the substrate plane. These results thus clearly indicate that the mechanism of self-assembly of TiO 2 nanosheets resulting in non-parallel orientation is correlated with the hydrophobic surface properties. Although His and Lys also demonstrated a relatively high contact angle, indicating hydrophobicity, the non-parallel orientation of TiO 2 nanosheets was not observed, probably due to a certain synergetic mechanism of non-parallel orientation of the TiO 2 nanosheets. 5 Water contact angle on the amino acid-functionalized single crystalline rutile TiO 2(110). Functionalization by amino acids was performed by immersing the substrate in amino acid solution (0.045 M) without pH control for 20 h. Here, we propose a mechanism for the self-assembly of TiO 2 nanosheets with non-parallel orientation with respect to the substrate plane, which was observed the most with Tyr-functionalized TiO 2 nanosheets, as schematically described in.
In the experimental condition of TiO 2 nanosheet coating, a sufficient number of Tyr molecules were adsorbed on the surface of the TiO 2 nanosheets with a carboxylic acid moiety in the saturated aqueous solution of Tyr with TiO 2 nanosheets. Therefore, the Tyr-adsorbed TiO 2 surface revealed the hydrophobic characteristics and a ζ-potential less than 30 mV. Lowering the ζ-potential of the TiO 2 particles induced by Tyr also resulted in slight aggregation in the suspension, although this was not significant enough to affect the results of dynamic light scattering (Fig. The surface hydrophobicity also possibly induced segregative hydrophobic inter-particle interactions due to synergetic interactions with the surrounding polar water as the solvent. Finally, the stacking of anisotropic nanosheets could have been the result of the driving force of the segregative hydrophobic interactions among the TiO 2 nanosheets under a low electrostatic repulsive force. The casted suspension became concentrated during the evaporation of the solvent in the film coating process of the TiO 2 suspension onto FTO or glass substrates.
Furthermore, the segregative hydrophobic inter-particle interaction from the hydrophilic FTO or glass substrates resulted in the non-parallel orientation of the anatase TiO 2(001) plane with respect to the substrate plane to avoid non-favorable contact between the hydrophilic substrate and hydrophobic Tyr-functionalized TiO 2 surface. Scheme 3 Plausible mechanism of self-oriented TiO 2 nanosheets for nonparallel orientation by the printing process proposed in this study. This mechanism is also supported by a controlled experiment with acetone addition in the suspension at the most favorable condition (Tyr-functionalized TiO 2 nanosheets under pH = 4), which significantly degraded the expected non-parallel orientation of the TiO 2 nanosheets (Fig. This was probably due to a decrease in the segregative hydrophobic interaction among particles, since acetone decreases the polarity of the solvent compared with water. In addition, hydrogen bonding between the hydroxy groups in Tyr moieties or between Tyr and the surface of TiO 2, which was typically covered with hydroxy groups especially in aqueous solution, possibly stabilized the stacked nanosheets on the FTO since a controlled experiment with a few simple saturated fatty acid compounds did not give any indication of non-parallel orientation (results are not provided). Although His and Lys also demonstrated a relatively high contact angle, indicating hydrophobicity on the TiO 2 surface , non-parallel orientation of the TiO 2 nanosheets was not observed.
This could be due to the following two factors: (1) a relatively large electrostatic repulsive force in the coating conditions or (2) hydrogen bonding as an inter-particle force. In the study of His and Lys, both molecules possess a protonated ammonium moiety, so each surface is positively charged under the assembling condition (pH 7), none of the amino acid-functionalized TiO 2 nanosheets revealed non-parallel orientation with respect to the substrate plane. This is probably because the carboxylic acid provides chemical bonding on TiO 2 only in an environment possessing low pH regions, so amino acid functionalization is possible only in the low pH region. This is indicated by low coverage of Tyr in the high pH region, as analyzed from the Lineweaver–Burk equation based on Langmuir's adsorption model (Fig.
As a result of (1) low electrostatic repulsive force, (2) hydrogen bonding as inter-particle forces, and (3) segregative interactions between particles and surroundings, such as water and the substrate surface, TiO 2 nanosheet functionalized with Tyr, Cys, or Phe at a pH of ∼4 exhibited the most favorable non-parallel orientation of the (001) plane with respect to the substrate plane among the applied conditions. Electron transport properties of TiO 2 nanoporous films in DSSC To demonstrate the effect of the nano-morphology of nanoporous films on the electron transport properties of nanoporous TiO 2 electrodes, the parallel and non-parallel orientations of TiO 2 nanosheets with respect to the FTO substrate plane were examined in the DSSC device configuration composed of a Ru dye-sensitizer (N719), an iodine/iodide redox electrolyte, and a platinum counter electrode. The TiO 2 nanoporous network shows non-parallel orientation by Tyr-functionalization, presumably because it possesses fewer inter-particle defects through the nanoporous network in TiO 2 films, while the parallel orientation without any functionalization provides more inter-particle defects in the nanoporous TiO 2 film in case the films have the same thickness. Therefore, we prepared the two types of nanoporous TiO 2 nanosheet films with the same thickness (∼2 µm). A similar loading of dye-sensitizer on both parallel and non-parallel nanoporous TiO 2 (Table S1, ESI) indicates that both nanoporous TiO 2 film properties are not affected by the internal surface area and porosity of the nanoporous films. The electron diffusion coefficient in TiO 2 was determined by analysis of the transient short-circuit photo-current under modulated incident excitation in the DSSC device configuration.
The charge density as a function of the energy level in TiO 2, and the electron lifetime representing the recombination exhibits similar with each TiO 2 film (Fig. On the other hand, the electron diffusion coefficient in TiO 2 shows significant improvement (a factor of approximately 4) with non-parallel orientation of nanosheets compared with parallel orientation in TiO 2 nanoporous films (Fig.
S9, ESI) in DSSC.