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R. Nagarajan has written:
'Amphiphiles' -- subject(s): Self-assembly, Amphiphiles, Hydrophile-lipophile balance, Chemistry
'Nanoscience and nanotechnology for chemical and biological defense' -- subject(s): Safety measures, Congresses, Biotechnology, Chemical warfare, Biological warfare, Nanotechnology, Chemical detectors
R. Nagarajan has written:
'Amphiphiles' -- subject(s): Self-assembly, Amphiphiles, Hydrophile-lipophile balance, Chemistry
'Nanoscience and nanotechnology for chemical and biological defense' -- subject(s): Safety measures, Congresses, Biotechnology, Chemical warfare, Biological warfare, Nanotechnology, Chemical detectors
Considering that phospholipids are amphiphilic molecules, such as soaps and detergents, form "micelles" (globular aggregates whose hydrocarbon groups are out of contact with water). This molecular arrangements eliminates unfavorable contacts between water and hydrophobic tails (the fatty acids) of the phospholipids and yet permits the solvation of the polar head groups (the phosphate group).
Now, we have to consider that micelle formation is a cooperative formation, that is, an assembly of just a few amphiphiles cannot shield its tails form contact with water. Consequently, dilute aqueous solutions of amphiphiles do not form micelles until their concentrations surpasses a certain critical micelle concentration (cmc). According to this, above the cmc, almost all added amphiphiles aggregates to form micelles. The value of the cmc depends on the identity of the amphiphile and the solution conditions, for example, biollogical lipids, most of which have two large hydrophobic tails (the fatty acids), the cmc values are generally < 10-6 M.
This question is perhaps a little confused.
A saturated solution means that no more substance can be dissolved into it. The solution itself therefore - saturated or otherwise - does not need to be dissolved.
The question remains that if we have a saturated solution, how do we dissolve more stuff into it? If I have a litre of water and put in 359g of salt, it is now saturated. You can find this information on wikipedia for most common substances, it's on the right-side under "Solubility in water".
Anyhow, how can we put in more than 359g of salt? We can raise the temperature of the water. That's easy but raising the temperature means you should be careful not to destroy your product or boil off your water.
You don't always have to use water, either. Some things dissolve better in other solvents. If you want to dissolve oil, water isn't going to do a lot for you, but Hexane might. That's why we use nail polish remover (Acetone) instead of just washing our fingers in water.
Polar things like to dissolve in polar solvents. And non-polar things in non-polar solvents. Things that are both polar and non-polar (amphiphiles) can be used to dissolve polar things into non-polar solvents and vice versa. This is why we use detergent to remove fats from dishes using water, which would otherwise not mix.
Finally, pressure can matter but that's really just for gases and is probably beyond the scope of this question.
Note: Answering this question requires the assumption that by soaps, the person submitting the question meant typical carboxylic acid-containing products. Please read on to understand.
Background. (i) Recall that any time one discusses chemicals (molecules) in practical use, we are actually talking about large "populations"-- where the chemical population of even a few ounces of water in a cup with some added detergent and a drop or two of vegetable oil is literally many billions of billions larger than the entire human population of our planet. Water solutions and suspensions (e.g., respectively, a glass of salt water and of soapy water) are such enormous populations. Bottom line: Molecules are very small, and their practical populations in use are very, very big, almost inconceivably so.
(ii) Levels of acidity of water (aqueous) solutions are measured using the pH scale. The more acidic the solution the lower the pH (e.g., 0-1 is very acidic), while the higher the pH, the more basic/alkaline the solution (e.g., 13-14 is very basic). The pH scale is logarithmic, thus compressing large ranges of acidities into a small range of numbers. Hence, a one unit change in pH corresponds to a ten-fold change, a two unit to a 100-fold change, etc. in the concentration of the active acidifying agent.
(iii) Detergents are most often used to disburse water-insoluble substances and mixtures of substances. The cleansing properties of a population of detergent molecules depend on their ability to form structured aggregates in which many billions of detergent molecules surround a smaller number of molecules of the water-insoluble materials, enclosing them in a water-soluble shell.
(iv) Specifically, detergents are most often molecules that are amphiphilic ("loving both sides"): they contain a hydrophilic group ("water loving", a positively charged or other very water-soluble structure) and a hydrophobic group ("water fearing", e.g., a 8-16 carbon long hydrocarbon chain or a steroid) . This combination of groups works by forming large ("supramolecular") aggregates -- e.g., spherical "micelles" or other emulsifying structures. In these, the hydrophilic groups point outward toward the water, and the hydrophobic groups point inward and "dissolve" similarly hydrophobic substances (e.g., in a familiar sense, cooking grease, or hydrocarbons in oil).
(v) The actual "energetics" of why this works are actually quite complex, with some details of mechanism and driving forces being intriguing, and even counter-intuitive.
(vi) In terms of molecular structure, detergents and soaps are composed of charged amphiphiles. While some charged groups are charged at all pH values (e.g., the alkyltrimethylammonium group of the detergent CTAB), most others are charged only at particular pH values. This arises because of the particular chemical structures of the charged group of the detergent amphiphile.
(vii) The chemical structures of many common commercial detergents and soaps conjoin "greasy" alkyl chains derived from animal or plant fats with a group having an electrical charge of -1 unit at neutral pH values (pH=7, neither acidic nor basic). Here, the charged groups are salts of various kinds of acids. One typical type of acid used in detergent structures are termed carboxylates (salts of fat-derived carboxylic acids, or fatty acids), and another are termed sulfonates (salts of sulfonic acids).
(viii) Acids have a defined pH point of being 50% charged, termed a pKa. Carboxylic acids are considered weak acids, and their pKa = pH 4.5; the proportion of carboxylates in a population that are charged at a particular pH is altered above and below this point. Molecules in a population of carboxylate detergents are almost all negatively charged at pH 6.5 and above, while at pH 2.5 they are almost all uncharged/neutral. Sulfonates, on the other hand, are salts of a extremely strong acids; their pKa is actually < 0 (negative!); hence, they remain negatively charged across the full normal pH range of aqueous solutions. (Sulfonic acids can only be made neutral by acidifying the aqueous solution in a way that is impractical with regard to human handling.)
Question answer. A detergent containing a sulfonate group likely "works better ... at all pH ranges" than a typical carboxylate-containing soap at all pH ranges, because at some pH values, the carboxylates do not form the necessary charged structure to be efficient amphiphiles that can form hydrophobe- (e.g., oil and grease) solubilizing aggregates such as micelles. Sulfonate detergents on the other hand remain charged and so effectively amphiphilic at all accessible aqueous pH values.
2-letter words
am
3-letter words
ama, ami, amp, amu
4-letter words
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5-letter words
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6-letter words
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7-letter words
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8-letter words
amadavat, amalgams, amandine, amanitas, amanitin, amaranth, amarelle, amaretto, amassers, amassing, amateurs, amazedly, ambaries, amberies, amberoid, ambiance, ambience, ambients, ambition, ambivert, amboinas, amboynas, ambroids, ambrosia, ambsaces, ambulant, ambulate, ambushed, ambusher, ambushes, ameerate, amelcorn, amenable, amenably, amenders, amending, amentias, amercers, amercing, amesaces, amethyst, amiantus, amicable, amicably, amidases, amidines, amidogen, amidones, amidship, amirates, amitoses, amitosis, amitotic, amitrole, ammeters, ammocete, ammonals, ammoniac, ammonias, ammonify, ammonite, ammonium, ammonoid, amnesiac, amnesias, amnesics, amnestic, amnionic, amniotes, amniotic, amoebean, amoeboid, amorally, amoretti, amoretto, amorists, amortise, amortize, amotions, amounted, amperage, amphibia, amphioxi, amphipod, amphorae, amphoral, amphoras, amplexus, ampoules, ampullae, ampullar, amputate, amputees, amreetas, amtracks, amusable, amusedly, amygdala, amygdale, amygdule, amylases, amylenes, amylogen, amyloids, amyloses
9-letter words
amadavats, amanitins, amaranths, amarelles, amarettos, amaryllis, amassment, amatively, amauroses, amaurosis, amaurotic, amazement, amazingly, amazonite, ambergris, amberinas, amberjack, amberoids, ambiances, ambiences, ambiguity, ambiguous, ambitions, ambitious, ambiverts, amblyopia, amblyopic, ambrosial, ambrosias, ambrotype, ambulacra, ambulance, ambulated, ambulates, ambuscade, ambushers, ambushing, amebiases, amebiasis, amebocyte, ameerates, amelcorns, amendable, amendment, amenities, americium, amethysts, ametropia, ametropic, amidogens, amidships, aminities, amitroles, ammocetes, ammoniacs, ammoniate, ammonites, ammonitic, ammoniums, ammonoids, amnesiacs, amnestied, amnesties, amoralism, amorality, amorettos, amoristic, amorously, amorphous, amortised, amortises, amortized, amortizes, amounting, amperages, ampersand, amphibian, amphibole, amphiboly, amphioxus, amphipods, ampleness, amplidyne, amplified, amplifier, amplifies, amplitude, ampullary, amputated, amputates, amusement, amusingly, amygdalae, amygdales, amygdalin, amygdules, amylogens, amylopsin, amyotonia
10-letter words
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11-letter words
amalgamated, amalgamates, amalgamator, amantadines, amaranthine, amaryllises, amateurisms, amativeness, amazonstone, ambassadors, ambergrises, ambiguities, ambiguously, ambisexuals, ambitioning, ambitiously, ambivalence, ambiversion, amblygonite, ambrosially, ambulations, ambuscaders, ambuscading, ambushments, ameliorated, ameliorates, ameliorator, ameloblasts, amenability, amenorrheas, amenorrheic, amercements, amethystine, amiableness, amicability, aminopterin, aminopyrine, ammoniating, ammoniation, ammonifying, ammunitions, amobarbital, amoebocytes, amontillado, amoralities, amorousness, amorphously, amortizable, amoxicillin, amoxycillin, amphetamine, amphibolies, amphibolite, amphibology, amphibrachs, amphictyony, amphimacers, amphioxuses, amphipathic, amphiphiles, amphiphilic, amphiploids, amphiploidy, amphisbaena, ampicillins, amplenesses, amputations, amusingness, amygdaloids, amyloidoses, amyloidosis, amylopectin, amyloplasts
12-letter words
amalgamating, amalgamation, amalgamators, amateurishly, amazonstones, ambassadress, ambidextrous, ambitionless, ambivalences, ambivalently, ambiversions, amblygonites, ambulatories, ambulatorily, ameliorating, amelioration, ameliorative, ameliorators, amelioratory, amentiferous, amiabilities, amicableness, aminopterins, aminopyrines, amitotically, ammoniations, amobarbitals, amontillados, amortization, amoxicillins, amoxycillins, amperometric, amphetamines, amphibiously, amphibolites, amphibrachic, amphictyonic, amphidiploid, amphisbaenas, amphisbaenic, amphitheater, amygdaloidal, amylopectins
13-letter words
amalgamations, amativenesses, ambassadorial, ambidexterity, ambiguousness, ambisexuality, ambitiousness, ameliorations, amenabilities, amiablenesses, amicabilities, aminoaciduria, aminophylline, amitriptyline, amniocenteses, amniocentesis, amorousnesses, amorphousness, amortizations, amphibologies, amphictyonies, amphidiploids, amphidiploidy, amphiploidies, amphiprostyle, amphitheaters, amphitheatric, amplification, amusingnesses, amyloidosises
14-letter words
amateurishness, ambassadorship, ambassadresses, ambidextrously, amicablenesses, aminoacidurias, aminopeptidase, aminophyllines, amitriptylines, ammonification, amphibiousness, amphiprostyles, amplifications
15-letter words
ambassadorships, ambidexterities, ambiguousnesses, ambisexualities, ambitiousnesses, aminopeptidases, ammonifications, amorphousnesses, amphidiploidies, amphitheatrical
16-letter words
amateurishnesses, aminotransferase, amphibiousnesses
17-letter words
aminotransferases, amphitheatrically
663 words found.
