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Membrane filters you need to know and their properties

Bryan Nesbit

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Membrane filters or commonly known as “membranes” are microporous membranes with specific pore size ratings. It is also called a sieve, microporous filter, or screen. Cellulose acetate membrane filter preserves or filter particles bigger than the pore size. If there are particles slighter than the pore size, other mechanisms will be used. There are different types of membrane filters, such as nylon, cellulose acetate, mixed cellulose ester, or MCE membrane filters. Here are more membrane filter types and their attributes.

The mixed cellulose ester

MCE is composed of cellulose acetate and nitrocellulose. It has a high porosity and can provide a higher flow rate. It also has a high level of protein binding, which can be prohibited by pretreatment or application. MCE is a standard membrane that can be used in many laboratory applications, such as filtration and sterilization of biological fluids, pollution analysis, microbiology, and air monitoring. The membrane is able to be converted into transparent to view the particles collected during the filtration process.

Cellulose acetate-

coated cellulose acetate consists of cellulose acetate cast on a non-woven polyester carrier. It has a non-fiber releasing ability, and the protein binding level associated with nitrocellulose is low. It also has a low level of static charge and chemically enhances compatibility with low molecular weight alcohols. The coated cellulose acetate is used as a pre-filter or clarification filter.

Hydrophilic PTFE

Hydrophilic PTFE has characteristics described as having the greatest resistance to chemicals and pH. The membrane has a high level of flow rate and almost no water-extractable. When the membrane is wetted with water, it is transparent to the naked eye, so it is very suitable for use in HPLC, organic solvents, and other aqueous mixtures.

Hydrophobic

PTFE The characteristic of hydrophobic PTFE is that it has a high porosity is very thin and behaves like a monolithic retention membrane. It also has a passive effect on most corrosive chemical solvents, alkalis, and strong acids. The membrane traps water-containing aerosols by sterilizing the gas. It is also used for gas and air discharge so that gas can freely pass through the membrane, and at the same time prohibit liquid from entering. This protects the best samples and vacuum pumps. In addition, hydrophobic PTFE clarifies and sterilizes strong acids and other solvents that are incompatible with other membrane filters.

Nylon

nylon membrane filters are made by impregnating polyester fiber webs with polymers made of nylon. This makes the membrane durable, heat-resistant, and essentially hydrophilic. Because it is hydrophilic, it is suitable for alcohol and aqueous samples. The membrane filter can be used to sterilize, filter, and clarify organic aqueous solutions.

Cellulose acetate

The membrane filter is composed of diacetate and cellulose triacetate. It is characterized by high strength and low electrostatic charge. The advantage of using it is that it can be repeatedly disinfected without losing its integrity or changing its bubble point. Associated with MCE membrane filters in stipulations of their solvent confrontation to alcohol molecular weight increase at low levels.  Cellulose acetate is used to enhance the recovery of positive organisms and filter enzyme solutions. It is also used for cytological diagnosis and receptor binding research.

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Rapid production of porous cellulose acetate membrane for water filtration using readily available chemicals

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Abstract

We describe a chemistry lab experiment using everyday elements and readily available chemicals to introduce porous polymer membranes to high school and college students. The principle of membrane filtration is illustrated by filtering solutions containing watercolor pigments or food coloring, while the food coloring is completely soluble in water and easily passes through the membrane. . The laboratory experiment can be performed in a 2 hour activity and is intended to (1) expose students to an exciting new field of materials science. He familiarizes them with porous membranes for the production of drinking water and presents them with a model elimination technique that uses the acid / base theory. In Switzerland, 52 high school students and 55 high school teachers have already successfully completed the laboratory experience and found the activity interesting and motivating.

 

introduction

Importance of safe drinking water

Access to clean and safe drinking water remains a global problem. In developing countries, around 80% of diseases are linked to poor water and sanitation conditions. Among the most common health risks of unclean drinking water are water-borne illnesses caused by pathogenic bacteria, viruses, and protozoan parasites. In a comprehensive study, Bain and colleagues examined the microbial quality of drinking water and estimated that approximately 1.8 billion people worldwide use a source of drinking water contaminated with E. coli or other bacteria. thermotolerant coliforms (TTC).

Various approaches, with their inherent advantages and disadvantages, have been studied for eliminating microorganisms linked to waterborne diseases. The portable water purification devices currently in use include systems based on ultra and microfiltration membranes, ceramic filters, activated carbon filters or chemical halogen disinfection. The disadvantages of the most efficient systems are, in general, their complex installation and their periodic maintenance, which leads to high operating costs and, consequently, makes these systems unsuitable for developing countries. In addition, many point-of-use treatment devices are not effective against all possible contaminants. Therefore, new water treatment technologies are being explored.

Water quality issues are an integral part of many high school chemistry courses, and various experiments have been developed as educational laboratory procedures. Water filtration experiments for the removal of nanomaterials have already been described and a laboratory experiment comparing various biochemical separation technologies (including filtration) has been presented. The experience presented here differs from previous approaches in that the filtering device itself (a porous membrane) is made by students from standard materials, then its separation performance is tested.

Cellulose Acetate Membrane for Water Filtration

In this article, we describe a laboratory experiment to produce a cellulose acetate membrane filter for drinking water which, in its production stages, resembles the commercially available water filter, but which is accomplished using everyday items such as a kitchen blender, glass dishes, rulers and chemicals readily available. The entire experiment can be performed in a 2 hour laboratory exercise. Supporting information for this article includes a student brochure and instructor notes for conducting the classroom experience (approximately 20 to 40 students). The production of membranes is based on the addition of calcium carbonate to a solution of cellulose acetate dissolved in acetone. Glycerol is also added to the reaction mixture and acts as a pore spacer. The polymer solution is then mixed using a kitchen mixer, and the resulting dispersion is spread on a glass plate using a stainless steel ruler. After evaporation of the solvent in ambient air, the calcium carbonate and glycerol particles are washed from the polymer matrix in an acid bath and then rinsed in a water bath.

Functional test of the membrane using watercolor and food coloring

Students test the performance of the membrane obtained with a solution of watercolor and food coloring. Although, when mixed with water, both give colored water, the color of the food used is a water-soluble dye, and watercolor is a dispersion of pigments, with particles between 40 and 80 µm in size. The watercolor solution based on pigments is first passed through the membrane. Then the filtration is repeated with the food coloring solution. In both cases, students are invited to record their observations. The experiments with the two solutions are then repeated with a standard filter for a Buchner funnel.

Procedure

Equipment and chemicals

The experiment uses the infrastructure and materials available in a university-level chemistry laboratory (see Information on teaching support and notes to students), as well as certain additions, which can be easily obtained:

• Kitchen mixer with at least 800 W of power (eg Philips HR 2195/04)

• Mirror or glass plate (148 × 210 mm2 or larger area)

•           Tape

• Ruler with stainless steel edge or aluminum profile.

• Two plastic tanks for dilute hydrochloric acid and a double boiler.

• Cellulose acetate (Sigma-Aldrich n ° 180955)

• Calcium carbonate (Sigma-Aldrich No. 21069)

• Watercolor (for example, Artists Loft Fundamentals watercolor pans set on amazon.com)

• Food coloring (for example bright blue FCF E133)

Preparation of a solution of cellulose acetate polymer

Preparation of the cellulose acetate dispersion

All of the cellulose acetate membrane filter was transferred to a kitchen mixer. Then, 41 g of calcium carbonate and 17.6 g of glycerol were added, and the suspension was stirred for 3 minutes in the highest setting of the kitchen mixer. The dispersion was placed in a new 250 ml Schott bottle and closed to limit evaporation of the solvent. The kitchen mixer was immediately filled with water to precipitate the remaining dispersion and the polymer waste was deposited in household waste.

Removal of calcium carbonate particles

To remove the calcium carbonate particles, a plastic container was filled with 5 L of water and another container with 5 L of hydrochloric acid (0.24 M). The mirror plate containing the membrane sheet was then immersed in the hydrochloric acid bath. The membrane sheet was released from the mirror plate, and gas bubbles indicated the removal of the calcium carbonate particles. After 10 minutes, the membrane sheet was transferred to the container containing only water and washed for an additional 5 minutes. Finally, the membrane sheet was removed from the water bath and placed on a cloth. Another kitchen towel was used to dry the membrane.

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Health

Orlando Dermatologist Reports Coronavirus Rash- Sunlight Needed for Vitamin D

Chris Rynolds

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Getting to deal with a whole new disease is very unsettling. No one has answers to anything, and that is enough to cause panic across any nation.

Well, that is precisely what is happening now with the Coronavirus. All the symptoms cropping up from different areas is bringing in more worry and doubt. The Coronavirus is an upper respiratory disease that gets in the way of your breathing, and it makes it harder for air passage in and out of the lungs. And now, there is something else worrisome — the Coronavirus rash.

So what is this rash, and where has it come from?

Is there any relation between skin rashes and Coronavirus

Doctor around the world including any Orlando dermatologist attest that it is not unusual to see skin rashes on someone infected with a viral infection. Just like herpes that appears around the lips and chickenpox that present all over the body.

The reasons this can happen is one, the rashes are a by-product of a robust immune system fighting against the virus. And two, it could be that the virus is directly affecting the skin cells as in the case of the chickenpox. Studies on the sources and targets of the coronavirus rash are still unknown.

The rashes have manifested in several ways so far. These are:

  • Head to toe rashes
  • Hive-like eruptions
  • Blisters
  • Purple rashes across the body
  • Bumps and lesions on the heels and toes

Now, what is perplexing is that these rashes are presenting on younger coronavirus patients. But any Orlando dermatologist should not make any conclusions yet as it is known that sometimes viral infections can impact almost every organ in the body, including the skin. The astonishing part is that the rashes are presenting differently from one patient to the other.

Types of rashes reported

Livedo Reticularis

The first kind of rash is the Livedo reticularis which is a vascular condition. It is characterized by mottled, purplish discolourations that mostly appear in the legs and appear to form a net-like pattern.

Petechial

This rash appears like a bright red, pinpoint rash that is commonly seen in other ailments. It is caused by bleeding under the skin.

Vesicular

A vesicular rash is diagnosed when a rash appears in the same spot as multiple vesicles with fluid trapped under the top layer of skin. The blisters are painful to touch, which make it hard to resist touching because they are itchy.

Acral Ischemia

This is a chicken-pox-like rash that appears specifically on the toes. It seems to be raised, looks like frostbite because of the purple lesions. These rashes are what has been named the COVID toes.

Morbilliform

These rashes look like measles rashes. They consist of maculopapular skin eruptions and are mostly because of hypersensitivity in patients taking antiretroviral and antiepileptic drugs. It is also a common outcome in viral infections like Coronavirus.

Urticaria

These are commonly known as hives or nettle rash. They are an outbreak of red bumps that are mostly triggered by several things, include medication reactions, allergies and infections.

Is there a cure for these rashes?

Any Orlando dermatologist would love to say that there is, but there is no known cure for the rashes. What doctors are doing is keeping the lesions in control using anti-inflammatory medications. And the fact that they are presenting in different forms makes it more challenging to come up with one specific cure.

With that said, it is still advisable for anyone showing any of the above symptoms to seek medical assistance immediately. Not all rashes are a result of Coronavirus, so it is safe to see a doctor first. So eat right and know that sunlight needed for vitamin D, especially in people of colour is essential too.

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Health

The Rising Importance of Orange County Family Doctors and Family Medicines

Chris Rynolds

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Are you thinking of getting an orange county family doctor? You may ask us, why do you really need one? Well, there are a ton of reasons why you need a permanent family doctor for yourself and your family. A family doctor is the first reliable and knowledgeable opinion source for your medical conditions keeping in mind your medical history, allergies, lifestyle, and preferences. A good family doctor not only looks into all your medical concerns but also facilitates the prevention of not just any physical but also all your mental, emotional, and spiritual dilemmas. Over the long-term, you can form a bond with your primary care physicians that will give you motivation and encouragement to share all your problems and concerns with them without any hesitation. You can also get a solution to all your physical and mental problems. 

Having good primary care now is our best hope for a healthy future tomorrow. And one asset that can contribute to this healthy and prosperous future is the orange county doctors and physicians. From providing treatment to all primary and short-term medical conditions to diagnosing chronic and long-term diseases, family doctors hold an undeniably important place in everyone’s lives. A properly maintained and operated family community clinic isn’t only a blessing in a patient’s life but can also contribute towards social stability. It’s a prominent place where you cannot only consult your family doctor but also get all your tests and scans performed to detect any medical condition. This information can be handy for your doctor to treat and eliminate your health condition.

Why are Orange County Family Doctors & Family Medicines Important?

The need/reasons to have orange county family doctors & family medicines are endless. However, we are stressing on the primary five reasons that make it clear as to why their presence can make your life healthier and tension-free.

 

 

  • Your family doctor does a lot more than you notice

 

 

 It would be ignorant to think that your primary care physicians just do some yearly medical check-ups. They treat and cure a lot more medical conditions that you think. The list goes on from taking care of emergencies to performing minor surgeries, treating infections and allergies, delivering babies, prescribing pills. Still, sadly a lot of their work generally goes unnoticed. Your family doctors are the bedrock of all your and your family’s immediate and long-term medical needs. 

 

 

  • Your family doctor knows you and your history 

 

 

Your family community clinic has all records and reports of your complete medical history. They know about all of your infections and allergies and any medical condition or disease that you may be suffering from. They also have a good idea of your psychological approach to different treatments or methodologies. This can be helpful in situations where you may need any advanced or specialist treatment for any reason. In such cases, your orange county physicians can recommend you to doctors or specialists that will be the most suitable for your condition. 

 

 

  • Family doctors team up with other healthcare professionals 

 

 

In case you are facing more than one medical condition, be it physical or mental, your orange county family doctor will easily co-ordinate with your other doctor or health care responder to keep in track all your treatment to help you get back to your healthy and happy self as soon as possible. They can provide any proactive measures and precautions to your other doctors that can guide them to understand and remedy your condition more quickly and more accurately.

 

 

  • Your family doctor can save your life and your money 

 

 

Statistics have shown that your primary care physicians can detect up to 95 percent of their patient’s chronic medical conditions and diseases in their early stages if you keep up with your regular appointments and check-ups. And when these conditions are discovered at their preliminary stages, they can be treated in under 5 percent of the health budget of the amount it would take for the treatment of such diseases and disorders in the long term. Not to forget that any condition caught in its primary stages is more easily beatable than at an advanced and powerful stage. So the next time you or your family members have an appointment with your family community clinic, don’t skip it. 

 

 

  • Your family doctors can take care of you and your family for a lifetime 

 

 

Be it a case of simple flu or something as serious as a cardiac attack; it’s most likely that your first call will be to your orange county family doctor. Be it, infants and newborns, or senior citizens, your family doctor, can attend patients of any age, gender, and medical condition and provide them with the proper diagnosis on time. If the situation calls for special attention, they can quickly connect you to a specialist keeping in mind your medical and family history. Your family doctor looks after you and your family’s unique and personalized needs and takes care of your health for any medical emergency

 

Now you must have understood how vital your orange county physicians are and what crucial role they play in your life. From providing immediate medical attention to assisting and supporting you through a major health condition, your family doctor always plays an active part in your life. They play a crucial role in identifying, explaining, and providing the best possible treatment of all kinds of health queries and concerns. Family doctors are the guardians of our life that can form a long-term relationship with their patients. You should keep in mind that no matter how technologically advanced things become, nothing can replace the human side of a doctor-patient relationship. So next time you see your primary care physician don’t forget to thank them for everything they do for you. 

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